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20 January
The challenge in detail, and in general
- Can Eye Color Have An Effect on Vision?, NYTimes, 19 Jan 2009
- Trying Everything and Anything for Autism, NY Times, 19 Jan 2009
- Purple Heart is Ruled Out for Traumatic Stress, NY Times 7 Jan 2009
- Psychiatrists Revise the Book of Human Troubles, NYTimes, 17 Dec, 2008
- Study Finds Drug Risks with Newer Antipsychotics, NYTimes 14 Jan 2009
- A Problem of the Brain, Not the Hands: Group Urges Phone Ban for Drivers, 12 Jan 2009
- A Love Vaccine, 12 Jan 2009
- Sex and Depression: In the Brain if not the Mind, NYTimes 19 Jan 2009
- My Genome, My Self, NYTimes, 11 Jan 09 (see also The Self: Genes, Environment, Chance, and ... Free Will?
"The more scientists look, the more they're able to tease romance apart into its individual strands--the visual, auditory, olfactory, tactile, neurochemical processes that make it possible."
Jeffrey Kluger, "Why We Love", Time Magazine, 17 January, 2008
"Moral intuitions ... are being explained with tools from game theory, neuroscience, and evolutionary biology"Steven Pinker, "The Moral Instinct", NYTimes Magazine, 13 January 2008
"if time doesn't exist, why do we experience it so relentlessly? Is it all an illusion?"The response in general
Assemble a team of people with different backgrounds/perspectives to look into what is emerging from scientific exploration, become familiar with it and its implications, become involved directly and/or by helping others understand/become involved
Who are we? (your intros on course home page)- What distinctive experiences/characteristics do you bring to the conversation this semester?
- List three questions that you'd like to see explored during the semester
The challenge more concretely
Neurobiology and BEHAVIOR ... what is "behavior"?
| Everything we can observe another organism/person doing from outside them, together with everthing we think we need to imagine going on inside them to account for what we observe from outside (emotions, drives, creativity, consciousness, agency, rationality, self?) |
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Image by Andreas Vesalius (1514-1564), contemporary of Copernicus, suggested (less than 500 years ago) that nervous system rather than heart was origin of behavior (see Milestones in Neuroscience Research for a time line extending from 4,000 B.C.). | 
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Image by Rene Descartes (1596-1650). Set framework for several centuries (and continuing) discussion: mind and body distinct things or same thing? |
| Nervous system is material object, part of body, can be touched, manipulated, measured. What IS the relationship between brain (nervous system) and behavior (broadly defined to include human experience)? Subset of this are questions such as the relation between mind and brain, mind and body, matter and spirit, matter and form ... | |||
The core of the challenge
- Emily Dickinson (1830-1886)
- Francis Crick, 1995: The Astonishing Hypothesis: "a person's mental activities are entirely due to the behavior of nerve cells ... and the atoms, ions, and molecules that make them up and influence them".
- V.S.Ramachandran, 2003: " it never ceases to amaze me that all the richness of our mental life - all our feelings, our emotions, our thoughts, our ambitions, our love life, our religious sentiments and even what each of us regards as his own intimate private self - is simply the activity of these little specks of jelly in your head, in your brain. There is nothing else"
- Paul Grobstein, contemporary: "Brain = behavior, there isn't anything else."
- Descartes (among others) was ... wrong? We are actually nothing more, and nothing less, than organized clumps of matter? From which it follows that ... ?
Brain = behavior?, from a "scientific" approach:
The Nature of Science
Science as Story Telling and Story Revision
(article, web resources, on-line forum)
Relevant both as context for course and as introduction to fundamental feature of brain, "loopiness"
| Linear science | Seriously loopy science |
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| Science as body of facts established by specialized fact-generating people and process
Science as successive approximations to Truth
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Science as ongoing process of getting it less wrong, potentially usable by and contributed to by everyone
Science as ongoing making of observations, intepreting/summarizing, making new observations, making new summaries Science as process of inquiry into anything, one which everybody is equiped to do/can get better at/be further empowered by, and contribute to - a way of making sense of what is but even more of exploring what might yet be |
| If science is as much about creation as discovery then the "crack"is a feature, not a bug ... and differences among people are an asset to the process rather than a problem or an indication it isn't working |
Trying It Out
Which of the following two stories do you prefer?- The earth is flat (Flat Earth Society)
- The earth is round
Because of ...
- personal observations?
- observations made by others (personally verified or not)?
- social stories (heard from others)?
- usefulness?
Is one or the other story true? Have there been others? Are there others? Will there be?
Which of the following two stories do you prefer?
Because of ...
- personal observations?
- observations made by others (personally verified or not)?
- social stories (heard from others)?
- usefulness?
- is one or the other story "true"? are there others?
Is one or the other story true? Have their been others? Are there others? Will there be?
Scientific stories are
frequently efforts to summarize the widest possible range of
observations, always motivate new observations and hence new stories,
should never be understood as "authoritative" or "believed in", do not
compete with or invalidate other stories.
Key issues about scientific stories
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Which story do you prefer about brain and behavior?
| Descartes et al: There is brain and mind (or soul or ...) | 14 |
| Dickinson et al: Its all brain/neurons/matter ... | 15 |
| Unsure/fence-sitting/other |
8 |
Issue is not "Truth" but whether there is a good "summary of observations", "working hypothesis", something that contributes to getting it continually "less wrong" is useful for the ongoing generation of new stories in science and in culture at large ... Keep "loopiness" in mind, not only for science but also for the brain
Our task for the semester (and beyond?):
to try and make sense of an existing and continuing explosion of observations on the brain, observations that have the potential to greatly influence our sense of ourselves and our relation to the world .... and to help others make sense of it as well.
Your starting thoughts about "brain=behavior", about science as story? about loopiness? ... are they good summary of observations? stories? What observations do they not incorporate? What new questions do they raise?
27 January 2008
Starting thoughts, from the forum
The idea of loopy science is appealing, it makes sense. A lot of science is always changing. Even the most definitive of rules have exceptions. (F=ma included). The only problem is that the way the general public is to anticipate that anything that comes from a scientist has to be ‘true’. Look at toothpaste ads, or dandruff shampoos – ‘70% of researchers say…’ or ’96% damage control, tested and proven’. It’s a cultural thing. Now if the producers were to say that this is true only for the cases tested, not many toothpastes will sell. What I am trying to say is that while the idea of loopy science is definitely credible, it is an idea that will be hard to put across to all of the general populace ... mmg
I too was only taught the linear way of exploring science and it was never too fun for me ... kjean
learning about this new way of thinking about science basically put into words what I had been striving to do that whole year but was held back from ... Brie Stark
The linear method we were all taught in grade schools I believe was appropriate for use as a learning tool. Many of the labs throughout grade school were not there to make you think about the scientific theory behind the lab topic, but to learn lab techniques and prove something at that current time. Sure eveything changes over time and something that might be true one day might not be true the next, but at the same time there needs to be some results or there would be no grants given to science. I believe there is a difference between the loopiness and the linear models, and they both serve their own individual purpose with the loopy model building on the linear model ... jwiltsee
Before coming to college I had always believed that there was absolute truth in science. I was taught that it was a fact that an airplane could fly and that the sun rises and sets in the sky every morning and evening, and I felt no reason to challenge these beliefs because they were constantly reinforced by my real life experiences. I realize that most people would find it ridiculous to spend a day, let alone a lifetime, trying to prove these “truths” incorrect. But there are scientists out there that spend their academic life trying to find contradictory evidence to these long held beliefs, and their work has and will continue to benefit us for years to come .... If there were absolute truth in science, science would eventually disappear ... bbaum
I do wonder how useful it is to eliminate the concept of truth. To what degree, I wonder, does human nature depend on truth and how do we respond to that need? Can humans feel trust without certainty? .... jlustick
Thinking about truth in science has led me to think about truth in more philosophical terms. What is truth really? Does truth even exist? If everything we know as reality comes from our brain and nervous system, how do we know what we perceive is actually reality and not out brain making things up? I don’t know, but thinking about things like this makes my head hurt ... Leah Bonnell
Once we establish and believe in the construction of the mind that is science, there can be definitive truth ... BeccaB-C
| Pro Descartes | Pro Dickinson |
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I still lean toward Descarte's view because I just can't understand how a bunch of chemical interactions could create a person's inner being/consciousness/sense of self/whatever you want to call it ... Crystal Leonard I feel like the mind is just a lens through which we experience a real world. If not, how is it that each of our minds are constructing reality, but we are able to agree on what this reality is (like things we come into physical contact with)? In that sense, I guess I agree with Descartes that the mind is not something we construct ... bkim Matter would be nothing had the concept of it not been a construction of the mind, or would it?? ... kjean I think Descartes understanding of the nervous system makes the system most easily understood by the most number of people (assuming they are all rational), and because of this fact, it therefore seems 'more true' or 'less wrong' ... bpyenson With Dickinson’s view it seems as if we’re living in a fantasy world constructed by our brains, which is fascinating to think of when writing science fiction or philosophy but I would like to think that what I’m experiencing is real and not something my imagination came up with ... fquadri i think that saying everything is a construct of our own brains gives us a more important role in the world than we really have ... hope How can something like morality simply be a result of firing neurons? ... shikha |
It would be nice to think that the world is almost magical in that my brain is creating what it wants ...Aybala50 I think our brains are complex enough to create complex emotions and our "inner mind." ... Leah Bonnell Dickinson’s idea, in conjunction with neurobiological information, may lead to a narrower, but more thorough exploration and understanding of the relationship between mind and brain. If we accept neurons and neurotransmitters as the basic mechanisms responsible for brain function, can we use these well-supported observations as building blocks to eventually comprehend the mind-brain relationship? ... kenglander So if we look at Dickinson the “the brain = behavior” we can start to look for some answers in the physical mass that is our brain ... ilja Without knowing the brain completely, I don’t think we can say that the dualism is right (or wrong) because the entity--the brain-- we are dealing with is not fully graspable. So, I would rather lean toward Dickinson’s view because that opens more possibilities ... redmink |
Start with overview of the "trend of the evidence":
- Behavior can be altered by altering the nervous system
- Traumatic brain damage
- Surgery, drugs, and ... ?
- Epilepsy as an instance
- Lots of aspects have behavior, even quite sophisticated ones, have "material" feel about them
- Surprising and quite sophisticated things can emerge from interactions of simple elements (of which the brain/nervous system is an example, as we'll see).
- It isn't that anything "disappears" as one discovers things related to
the brain but rather that the Brain gets "wider"
- Disadvantages?
- Advantages:
- ???
- would make the unobservable observable?
- Brain=behavior "True"? ("perhaps we just do not have the right microscopes yet"?). Good "story"?
- Are brains both sufficiently different and sufficiently similar to account for both differences and similarities in behavior?
- Do all things that influence behavior influence the brain?
- Is thinking a "physical" process? that can affect physical things?
- How do we distinguish between acting with and without thinking?
- Is morality/altrusim a function of the brain?
- Is "agency" a function of the brain?
- If everybody has their "own construct of what the world is" what follows from that?
- If the brain is itself a construction of the brain what follows from that?
- If brain = behavior, is all mystery lost? are there still "intriguing" things?
IF Emily et al are right:
- "brain"="nervous system"=body=matter, therefore all action/experience a function of organized matter? complexity from simplicity?
- Brains must not be only "reactive"
- Brains are to some degree different in different people
- Brains in given people must change with time/experience, must be affected by culture/language, nexus point for ALL influences on behavior?
- Brains must have different parts?
Some starting points: a sphagetti bowl? ("chains of neurons" or "hormones, chemicals")
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The sphaghetti (switchboard, "reflex") box
model
Virtues
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Sphaghetti (switchboard, "reflex") plus box
model
Virtues
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A rethinking - boxes in boxes
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The sphaghetti (switchboard, "reflex") box
model
Virtues
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Facing up to the stereotopy, stimulus-response problem ... freeing the box from the outside world, adding autonomy
| Harvard Law of Animal Behavior
"Under carefully controlled experimental circumstances, an animal will behave as it damned well pleases"
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The boxes inside boxes (with
"autonomy") model
Virtues
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If brain=behavior then the nervous system must not be a
stimulus/response machine (nor a bag of chemicals) that is invariant
and the same in everyone. It must instead be a different kind of "machine"
- somewhat different in different individuals,
- affected by both genes and experiences/culture,
- capable of
- different outputs for the same input
- taking in inputs with no output
- generating outputs with no input
- a "semi-autonomous" input/output box consisting of input/output boxes.
Go on to look at actual nervous systems to see if they satisfy expectations and to
address issues ... further iterations ("getting it less wrong") to come.
3 February
Issues for future consideration
Does our intelligence come from the presence of the “mind?” Do other, less intelligent creatures possess a mind, or do they only have a brain? ... bbaum
My pony has a lot of what I would term, common sense ... jrlewis
if this experiment were done with a human we would not be able to distinguish the signals coming from the brain as anything but just signals. Even if there was no body to communicate them would inner thinking still be going on? ... Sam Beebout
If the outside world is a construct of our mind, does this mean that a construct of the brain is controlling how the brain itself will act? It’s as if the brain as created a playground for itself, for which it can play in ... fquadri
we are in a a world where there is a box within a box within a box and then some. Our culture can be considered the mother of boxes, with all major inputs bouncing into us from our culture, and our reactions are to react within that box. sometimes our outputs stay within the box of the culture, and sometimes it bounces out. That way, our culture ends up effecting other culture boxes - which explains why nowadays there is a rise of anorexia in the eastern culture. That makes sense, doesn't it? ... hamsterjacky
in this model of the nervous system, there is NO foundational properties, there are no real built-in valuation systems of saying any aspects of the model are more important for its functioning than any other components. Maybe input is as equally valid as output. If that's the case, why can't we just switch the model on its head and make outputs inputs and inputs outputs, and see if the model holds 'true' then? .... bpyenson
I
too (like others before) like this idea of loopy science as I do the
idea of boxes within boxes as a representation for the nervous system.
Both offer a way out/around the set ‘rules’ that science is perceived
to be .... we
might soon abandon the input/output box model as we discarded the ones
before it and move onto a modification or a new one - one that has some
sort of explanation for contextual factors for indviduals
(culture,faith..), and also to keep the loopiness going ... mmg (see also kjean, ilja, drichard)
Immediate issues: boxes/outputs/inputs
It seems like the input/output box is favored by majority of the class. However, for me, stimulus/response model is still fine. Although I agree that input/output sounds more neutral and they add more complexity, I don’t have strong conviction to favor the input/output model yet. I think it is because I had been a strong believer who’s convinced that the function of the brain and behavior are solely based on chemical activity.So, it is hard for me to abandon my old belief, the concept of stimulus/response ... redmink
I've always been fascinated by the internal voice. What is it? How is it created? Obviously the internal voice doesn't have a specific input that leads to its formation, so it's created by one of the boxes within the box. But is the internal voice an output? ... Crystal Leonard
it seems to me that the essence of thought could really be compared to this box with no input signal ... Brie Stark (see also bkim)
It's not clear to me still how a box can produce output with no input, and vice versa ... Sarah Tabi (see also cc)
Now that we have a basic nervous system model as a reference I think we can confidently explore neurobiology and behavior ... Lisa B.
the boxes model still leaves open the possibility that there may be a metaphysical mind that operates outside of the physical. The boxes model has unexplained portions within the smaller boxes. How are inputs processed? What happens within the workings of the mind that creates and output, or not? ... eglaser
Even if you say all the way down, then what does the all the way down turtle stand on. What I'm trying to say is there must be a finite number of boxes that are within the larger boxes ... jwiltsee
how does this box model explain the recurrence of nightmares or images of traumatic experiences? How does the box model explain how we organize inputs once we receive them, and how we control outputs? ... nafisam
Since I am currently at a loss for how to investigate these boxes within boxes, I wonder if it is possible to explore the arrows that connect these boxes. Do they represent the neurons in the brain? ... kenglander
The "real" nervous system - an input/output box consisting of interconnected input/output boxes?
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| photo from Kemali and Braitenberg, Atlas of the Frog Brain, Springer-Verlag, 1969 |
Each box in turn (somewhat arbitrarily) subdividable into smaller boxes (with some differences among vertebrates, to return to)
And those ... yes, "its boxes all the way down"
The smallest box: neurons everywhere
Invertebrate nervous systems also have neurons, but differently arranged - makes sense?
Neuron as common, smallest box and as input/output element, connected to other boxes
- Cells, like other cells, but specialized to receive/process transmit "information" (as opposed to matter or energy)
- Size scale - tens of microns (10-6) meters)
- Larger boxes must differ in how smallest interconnected
- Relevance of numbers? enough to "account for all the uniqueness that exists among people"? ... 1012exp1012 possible nervous systems?
- Differences between people, differences between organisms due to .... not building blocks but assembly (architecture)
- Need to know how neurons work - to return to
Can use boxes->boxes ... ->boxes(neurons) to show that larger boxes interconnected, in relatively specific ways (anatomical specificity) and to rigorously specify "input" and "outputs" of largest box ... nervous system itself
- grey matter (soma, dendrites, pre-synaptic terminals, neuropil) vs white matter (bundles of axons, tracts)
- central vs peripheral nervous system (some ganglia, but largely axon bundles
- output elements of nervous system (motoneurons, plus) = neurons with axon terminating outside nervous system
- input elements of nervous system (sensory neurons, plus) = neurons with receiving surface (dendrites) outside of nervous system
- everything else = interneurons
- numbers/proportions: more reason to think of ns as "semi-autonomous"
So ... at least parts of our box within box model real ... and helps define "input" and "output" more rigorously
Implies: different regions on brain, different brains, different behaviors largely because of different assemblies of similar elements ("architecture")
The "real" nervous system - different if behavior different?
- Among different kinds of organisms?
- Among different individuals? within individuals over time?
- Notice that differences leave open the question of what causes differences (genes, experiences, activity, culture, etc)
- Implies that "information" can alter matter; not mysterious, "info" turns out to be perturbations of matter organization in neurons, can via metabolic processes influence organization/properties of neurons
10 February
From the forum
the brain is not a machine because we cannot always predict the outcome of a stimulus. But what about Psychology?... the whole point of my Experimental Methods and Statistics class is to design experiments and to critically examine data all in the ultimate goal of better understanding human behavior. I mean, isn't that what Psychology is about-- to understand and predict human behavior ... ? ... Anna Dela Cruz
I felt really great knowing that no one else had my brain. It made me think about this struggle for individuality that everyone has or certain people focus their entire lives on .... kjean
It would seem that since there are an almost infinite amount of combinations of neurons, which are each their own “computer”, that all humans would be vastly different, and any foundations, such as social norms, would not exist. Given the fact that they do exist, perhaps outside influences such as culture and social norms tend to even things out, and account for the similarities in behavior among specific groups of people .... nafisam
I do think that social and cultural influences or information shape the brains of groups of people. When people adapt a certain set of morals or certain way of thinking, they must also induce change in their neuron organization ... bkim
if the leach had been just freshly born when its nervous system had been removed, or if somehow a leach system was cloned and never put in a leach body would it still produce output? in more general terms, can a nervous system produce output in the complete absense of any previous input? If so, then what would be the purpose of learning other than to standardize the output of all of our brains? ... hope
could an individual alter the physical structure of his or her brain? ... ddl
Can you detect thoughts in the brain with an MRI? What is the physiology of a thought? ... eglaser
maybe thinking involves different parts of the brain, like the frontal lobe and temporal lobe, interacting with each other .... leah bonnell
At what point within the spaghetti web of interneurons does information go from unconscious to cortexual and conscious? - BeccaB-C
Our NS seems to be very complex and if it is responsible for our behavior, or can explain our behavior I think that maybe we have to look at some of the bigger boxes first ... ilja
The "real" nervous system - different if behavior different?
- Among different kinds of organisms?
- Among different individuals? within individuals over time?
- Notice that differences leave open the question of what causes differences (genes, experiences, activity, culture, etc)
- Implies that "information" can alter matter; not mysterious, "info" turns out to be perturbations of matter organization in neurons, can via metabolic processes influence organization/properties of neurons
Outputs - topographic organization - anatomical specificity
- Motoneurons located at levels of neuraxis related to location of muscles controlled
- Each motoneuron activates only one muscle
- Implications:
- "action" is not one output but pattern of activity across lots of them - "motor symphony"
- source of lots of additional variation in behavior
- lots of outputs/nervous system involved in any "action", is "distributed" characteristic
- need to understand how patterns of activity created, parts coordinated
- Sensory neurons terminate at levels of neuraxis related to location of receptors
- Implications
- "sensation"/"perception" not one input but pattern of activity across lots of them (across modalities and, as will be seen, in one modality - another "distributed" characteristic
- need to understand how inputs combined
- thought = pattern of activity across lots of neurons
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For additional information: |
Usefulness of the interconnected box model and ... another box?
- Capabilities of spinal cord
- Quadriplegia (slightly better) - relevance of topographic organization
- Christopher Reeves and ... , from NIH
- The "I-function"
Observations "surprising", but have to be accepted - Issue is "how to make sense of them"
Two kinds of behavior ("reflex" versus something-else) intuition probably not useful
- Spinal cord capable of very sophisticated activity
- Brain capable of quite unsophisticated activity
- Distinction between "reflex" and other things?
- "foot withdraws when irritated" - spinal cord capable of
sophisticated activity on own
- is ok ... given topography and "physical contiguity principle ("PCP")
- "person doesn't say ouch when foot irritated" - behavior frequently
depends on linking paths within nervous system
- is ok ... given topography and "physical contiguity principle ("PCP")
- "person doesn't move foot when hearing (or reading) request to do so" -
behavior frequently depends on linking paths within nervous system
- is ok ... given topography and "physical contiguity principle ("PCP")
- "person says foot irritation not felt/experienced" - behavior frequently
depends on linking paths within nervous system
- is ok ... given topography and "physical contiguity principle ("PCP") AND ..
- "behavior" can occur without it being experienced by the behaving organism AND ...
- neuronal circuitry adequate to support "feeling/experiencing" (I-function) is in the brain (spinal cord not needed for this function)
- Where is Christopher Reeves? Is he paralyzed? Does he feel pain? -
has to do with "mind", "self", "soul", "personality", "consciousness" ?
- words requiring redefinition in light of new experiences/observations?
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Ascending somatosensory
pathways Descending motor pathways
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If its all sensory neurons, motoneurons, interneurons, and signals moving among them (the I-function included), we need to look at signals, what they are, how they're handled ...
Signals:
- Resting potential
- Action potential
- Receptor and generator potentials
- Synaptic potentials
17 February
From the Forum
The fact that the parts of your body correspond to a certain section of the nervous system in an corresponding and relative manner never occurred to me. Nor did I pay much attention when I walked, talked, sat and stood about just how my body was accomplishing these requests ... SandraGandarez
thinking about an action and performing an action are different. Thoughts can be completely dissociated from inputs and outputs in the nervous system ... jrlewis
Could it be that autism is an anomaly, like the Reeves anomaly, of the I-function where somehow, some cords got tangled/cut/rearranged ... Brie Stark
I asked whether or not the "I-Function" is something used among neurobiologists or if the term/concept is just for the convenience of the class. I think it is important to understand where our class conversations intersect with the larger conversations that neurobiologists are having (see also Lisa B) ... We discussed the fact that the I-function is related to, but not the same as, the conscious/unconscious distinction, but I'm interested in learning more about where these two concepts overlap. In other words, if dreams are part of the unconscious, can they also be part of the I-function? ... jlustick
"I" am the focus of my actions, my actions are focused around me. Other people's perceptions of my personality is based on a series of actions that "I" am responsible for ... Sarah Tabi
it seems like the I-function is what we consider "self" ... Leah Bonnell
Which part of our body is truly essential to our individuality? And also, is there such a part? ... ilja
In order to reach a high level of competition, one must make the right action at precisely the right time. In a fast paced sport, such as fencing, these decisions are made in a matter of seconds.But at what point does the “I function” end, and muscle memory begin? ... Adam Zakheim
It was interesting to hear about the concept of pain being explained as a simple pattern of activity in one of the boxes of our nervous system. In our diagram of the system I would have thought it to be an input. After all, a person can percive pain without using their I-function. when a person burns their hand they withdraw the hand at the first feeling of pain, before the brain has time to register it. Does pain only be labeled pain if it is a part of the I-function? ... eglaser
maybe consciousness is simply being able to take in all the input signals from the environment and being able to potentially react to them. While the I-function is a part of consciousness--the part that focuses on thinking about how the "I" is going to interact with the environment. Perhaps the "I-function" fits under the larger umbrella term of "consciousness" ... bkim
for something as abstract and complicated as the I-function (a person's character, individuality, decision making), can just physical interactions between nuerons be held accountable? I find it hard to get my head around this divide ... mmg
The thing I'm still unsure about was in class we spoke about babies being different at birth and then converging to become similar in society. I think this is completely opposite. I believe that babies are very similar at birth, because they have no yet had the influence of society. I believe as individuals grow they diverge from one another, maybe not totally, but they diverge because of nurturing, society, morals, culture, and them just wanting to be different. This can swing back to the I function, where your individual self will make decisions and your mind will see things as it wants to construct them ... jwiltsee
For every unthinking action, is there also an identical set of neurons which allow that action to be regulated or produced within the constraints of the 'I' function box? Or is the 'I' function essentially able to tap into and oversee every other box within the human body ... ddl
If we were able to move the boxes required for walking lower in the nervous system, our brains may be able to accomplish more complex tasks because there is more room and energy for these tasks ... bbaum
Start with action potential, use it to raise questions that will lead to explanation of resting potential, use those ideas in turn to successively build up a set of more basic ideas that collectively account for all signalling.
- continual motion (diffusion)
- concentration gradients of charged particles (ions)
- specific membrane permeability
- passive current flow
- variable membrane permeability
Action potential - longitudinal battery which appears/disappears successively at successive points along an axon ("travels" at finite speed), "all or nothing" transient (millisecond range) event
- Helps to account for "thinking takes time"
- Is the common currency of "information" in nervous system cables (axons, axon bundles), of
all organisms
- Problem: how distinguish action from perception from thought?
- Solution: anatomical specificity ("see thunder, hear lightning")
- Is way to "see" otherwise unobservable
- Need to understand it - doing so will help make sense of other potentials, provide further insights into how ns COULD be behavior
To understand action potential, need first to understand resting potential - transverse battery, continuously present, with potential for continuous variation
| Organization based on random motion |
- Diffusion
- Selective permeability
- Charged particle movement, balance of diffusion and battery creation
- Stable
transverse battery, with potential for variation
- Concentration gradients, energy dependent ion pumping
- Can get action potential? what more?
24 February
The I-function
It now makes more sense to me why thinkinng sometimes makes me unable to do things. I'd always noticed that i couldn't do certain things, like driving or playing sports, if i thought about what i was doing, but i'd never thought about the reason. Maybe it is simply that thinking, or sending signals around in the "I-function", takes time, and when there isn't a lot of time the signals have to be sent directly to the muscles and skip the i-function ... hope
Now it makes more sense why I wasn't getting better, but worse for a while. Until I got used to the new routine, I was thinking about every step and because it wasn't more instinctual I wasn't playing as well. When I got a hang out the new moves, I started playing a lot better ... aybala50
I disagree that use of the I-Function impedes the execution of an act ... Olufemi.Nazsira
Action potentials: issues to keep in mind
Why is it that brain activity is so often portrayed as an electrical current when it is in fact a chemical one? It is interesting to note the inherent misconceptions about the brain that we must address. No electricity in the brain ... so how else has so called 'common knowledge' tricked us? ... eglaser
Do these chemicals and electric currents give rise to our thoughts and self-awareness as well? ... bkim
Is it just Sodium and Potassium that accounts for some of the best literature or art that is in the world today? ... mmg
It has often benefited me to look at the nervous system (and many other body systems) as a symphony of sorts. If all the individual instruments (the chemicals and proteins) play well, the body's song as a whole will be pleasing ... drichard
it is revealed that the girl has a rare genetic disorder which causes her to be insensitive to pain. Due to this insensitivity, the girl believed that she was a superheroine and often dared classmates to injury her ... Anna Dela Cruz
How much of this is in the hands of him/her? How much of experiencing pain is mental and how much is behavioral? ... BMCsoccer01
reaction time connects to the exercise we did in class where we proved through a computer program that it takes time to think. If thinking involves neurons, then it must also involve action potentials, which take time to travel ... Leah Bonnell
Whenever I've been close to stepping on something painful or running into something, I've always noticed the little delay before my body reacts to what I'm seeing. Instead of knowing that propagation is occurring and that all of these reactions are attempting to get me out of harm's way, I've always just thought that it was the surprise that caused my hesitation ... SandraGandarez
Issues to deal with more immediately
what would be the effect of two oppositely oriented action potentials moving into one another? ... ddl
Can action potentials move faster or slower? ... jlustick
Thinking of an action potential in this way can perhaps help explain how some input can have no output. If the cell membrane is not depolarized enough (ie it does not reach the threshold potential) an action potential will not be generated, it thus the input may not have an output ... shika (see also jwiltsee re pain)
We mentioned before that not all output boxes are connected to input boxes. Does that mean action potentials can be generated without stimuli? ... Sarah Tabi
Propagation
Notice it is NOT matter moving, nor energy, it is a perturbation (signal, information) |
Will propagate if started. How affect things? How started? Need to understand synaptic potentials, receptor potentials, but first ...
Lots of things can start it. Among them is something that provides answer to one of our box questions ...
And the big question ... Do signals actually start in the middle of the box? If so, how?
Yes, not mysterious, follows from what we know, if we add possibility of some differences in permeability of some membrane regions not mysterious, has interesting implications ...
- brain in a vat
- action without "personal responsibility"?
- epilepsy
- other things?
Go on to receptor potentials, synaptic potentials (how action potentials affect things, how boxes integrate, how signals stopped in box)
Input (sensory) signals - an example
- Neuronal receiving surface outside nervous system
- Sensory transduction - specific channels varying permeability in response to external events
- Receptor potential - continuously variable in space/time (like passive current flow
- Transformed into action potentials
- Coding in pattern of action potentials
- Significance for behavior?
- Restricted sample of "reality"
- All representations of "reality" in same form, in same signals as those created in nervous system itself
- Anatomical specificity IMPORTANT ("hear lightning, see thunder")
- Extra-sensory perception
- "five senses"?
- proprioception (muscle spindles, tendon organs, plus)
- pheromones
- others?
Synaptic potentials - Synaptic integration
- action potential vanishes at synapse
- intermediate chemical step: neurotransmitter release and ... (multiple control steps)
- permeability change leads to synaptic potential (alternate), also continuously variable in space/time
- summation - neuron as integrator rather than relay
- inhibitory synaptic potentials, algebraic summation
- is how to "stop" signals - significance for behavior?
20 January
The challenge in detail, and in general
- Can Eye Color Have An Effect on Vision?, NYTimes, 19 Jan 2009
- Trying Everything and Anything for Autism, NY Times, 19 Jan 2009
- Purple Heart is Ruled Out for Traumatic Stress, NY Times 7 Jan 2009
- Psychiatrists Revise the Book of Human Troubles, NYTimes, 17 Dec, 2008
- Study Finds Drug Risks with Newer Antipsychotics, NYTimes 14 Jan 2009
- A Problem of the Brain, Not the Hands: Group Urges Phone Ban for Drivers, 12 Jan 2009
- A Love Vaccine, 12 Jan 2009
- Sex and Depression: In the Brain if not the Mind, NYTimes 19 Jan 2009
- My Genome, My Self, NYTimes, 11 Jan 09 (see also The Self: Genes, Environment, Chance, and ... Free Will?
"The more scientists look, the more they're able to tease romance apart into its individual strands--the visual, auditory, olfactory, tactile, neurochemical processes that make it possible."
Jeffrey Kluger, "Why We Love", Time Magazine, 17 January, 2008
"Moral intuitions ... are being explained with tools from game theory, neuroscience, and evolutionary biology"Steven Pinker, "The Moral Instinct", NYTimes Magazine, 13 January 2008
"if time doesn't exist, why do we experience it so relentlessly? Is it all an illusion?"The response in general
Assemble a team of people with different backgrounds/perspectives to look into what is emerging from scientific exploration, become familiar with it and its implications, become involved directly and/or by helping others understand/become involved
Who are we? (your intros on course home page)- What distinctive experiences/characteristics do you bring to the conversation this semester?
- List three questions that you'd like to see explored during the semester
The challenge more concretely
Neurobiology and BEHAVIOR ... what is "behavior"?
| Everything we can observe another organism/person doing from outside them, together with everthing we think we need to imagine going on inside them to account for what we observe from outside (emotions, drives, creativity, consciousness, agency, rationality, self?) |
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Image by Andreas Vesalius (1514-1564), contemporary of Copernicus, suggested (less than 500 years ago) that nervous system rather than heart was origin of behavior (see Milestones in Neuroscience Research for a time line extending from 4,000 B.C.). |
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Image by Rene Descartes (1596-1650). Set framework for several centuries (and continuing) discussion: mind and body distinct things or same thing? |
| Nervous system is material object, part of body, can be touched, manipulated, measured. What IS the relationship between brain (nervous system) and behavior (broadly defined to include human experience)? Subset of this are questions such as the relation between mind and brain, mind and body, matter and spirit, matter and form ... | |||
The core of the challenge
- Emily Dickinson (1830-1886)
- Francis Crick, 1995: The Astonishing Hypothesis: "a person's mental activities are entirely due to the behavior of nerve cells ... and the atoms, ions, and molecules that make them up and influence them".
- V.S.Ramachandran, 2003: " it never ceases to amaze me that all the richness of our mental life - all our feelings, our emotions, our thoughts, our ambitions, our love life, our religious sentiments and even what each of us regards as his own intimate private self - is simply the activity of these little specks of jelly in your head, in your brain. There is nothing else"
- Paul Grobstein, contemporary: "Brain = behavior, there isn't anything else."
- Descartes (among others) was ... wrong? We are actually nothing more, and nothing less, than organized clumps of matter? From which it follows that ... ?
Brain = behavior?, from a "scientific" approach:
The Nature of Science
Science as Story Telling and Story Revision
(article, web resources, on-line forum)
Relevant both as context for course and as introduction to fundamental feature of brain, "loopiness"
| Linear science | Seriously loopy science |
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| Science as body of facts established by specialized fact-generating people and process
Science as successive approximations to Truth
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Science as ongoing process of getting it less wrong, potentially usable by and contributed to by everyone
Science as ongoing making of observations, intepreting/summarizing, making new observations, making new summaries Science as process of inquiry into anything, one which everybody is equiped to do/can get better at/be further empowered by, and contribute to - a way of making sense of what is but even more of exploring what might yet be |
| If science is as much about creation as discovery then the "crack"is a feature, not a bug ... and differences among people are an asset to the process rather than a problem or an indication it isn't working |
Trying It Out
Which of the following two stories do you prefer?- The earth is flat (Flat Earth Society)
- The earth is round
Because of ...
- personal observations?
- observations made by others (personally verified or not)?
- social stories (heard from others)?
- usefulness?
Is one or the other story true? Have there been others? Are there others? Will there be?
Which of the following two stories do you prefer?
Because of ...
- personal observations?
- observations made by others (personally verified or not)?
- social stories (heard from others)?
- usefulness?
- is one or the other story "true"? are there others?
Is one or the other story true? Have their been others? Are there others? Will there be?
Scientific stories are
frequently efforts to summarize the widest possible range of
observations, always motivate new observations and hence new stories,
should never be understood as "authoritative" or "believed in", do not
compete with or invalidate other stories.
Key issues about scientific stories
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Which story do you prefer about brain and behavior?
| Descartes et al: There is brain and mind (or soul or ...) | 14 |
| Dickinson et al: Its all brain/neurons/matter ... | 15 |
| Unsure/fence-sitting/other |
8 |
Issue is not "Truth" but whether there is a good "summary of observations", "working hypothesis", something that contributes to getting it continually "less wrong" is useful for the ongoing generation of new stories in science and in culture at large ... Keep "loopiness" in mind, not only for science but also for the brain
Our task for the semester (and beyond?):
to try and make sense of an existing and continuing explosion of observations on the brain, observations that have the potential to greatly influence our sense of ourselves and our relation to the world .... and to help others make sense of it as well.
Your starting thoughts about "brain=behavior", about science as story? about loopiness? ... are they good summary of observations? stories? What observations do they not incorporate? What new questions do they raise?
27 January 2008
Starting thoughts, from the forum
The idea of loopy science is appealing, it makes sense. A lot of science is always changing. Even the most definitive of rules have exceptions. (F=ma included). The only problem is that the way the general public is to anticipate that anything that comes from a scientist has to be ‘true’. Look at toothpaste ads, or dandruff shampoos – ‘70% of researchers say…’ or ’96% damage control, tested and proven’. It’s a cultural thing. Now if the producers were to say that this is true only for the cases tested, not many toothpastes will sell. What I am trying to say is that while the idea of loopy science is definitely credible, it is an idea that will be hard to put across to all of the general populace ... mmg
I too was only taught the linear way of exploring science and it was never too fun for me ... kjean
learning about this new way of thinking about science basically put into words what I had been striving to do that whole year but was held back from ... Brie Stark
The linear method we were all taught in grade schools I believe was appropriate for use as a learning tool. Many of the labs throughout grade school were not there to make you think about the scientific theory behind the lab topic, but to learn lab techniques and prove something at that current time. Sure eveything changes over time and something that might be true one day might not be true the next, but at the same time there needs to be some results or there would be no grants given to science. I believe there is a difference between the loopiness and the linear models, and they both serve their own individual purpose with the loopy model building on the linear model ... jwiltsee
Before coming to college I had always believed that there was absolute truth in science. I was taught that it was a fact that an airplane could fly and that the sun rises and sets in the sky every morning and evening, and I felt no reason to challenge these beliefs because they were constantly reinforced by my real life experiences. I realize that most people would find it ridiculous to spend a day, let alone a lifetime, trying to prove these “truths” incorrect. But there are scientists out there that spend their academic life trying to find contradictory evidence to these long held beliefs, and their work has and will continue to benefit us for years to come .... If there were absolute truth in science, science would eventually disappear ... bbaum
I do wonder how useful it is to eliminate the concept of truth. To what degree, I wonder, does human nature depend on truth and how do we respond to that need? Can humans feel trust without certainty? .... jlustick
Thinking about truth in science has led me to think about truth in more philosophical terms. What is truth really? Does truth even exist? If everything we know as reality comes from our brain and nervous system, how do we know what we perceive is actually reality and not out brain making things up? I don’t know, but thinking about things like this makes my head hurt ... Leah Bonnell
Once we establish and believe in the construction of the mind that is science, there can be definitive truth ... BeccaB-C
| Pro Descartes | Pro Dickinson |
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I still lean toward Descarte's view because I just can't understand how a bunch of chemical interactions could create a person's inner being/consciousness/sense of self/whatever you want to call it ... Crystal Leonard I feel like the mind is just a lens through which we experience a real world. If not, how is it that each of our minds are constructing reality, but we are able to agree on what this reality is (like things we come into physical contact with)? In that sense, I guess I agree with Descartes that the mind is not something we construct ... bkim Matter would be nothing had the concept of it not been a construction of the mind, or would it?? ... kjean I think Descartes understanding of the nervous system makes the system most easily understood by the most number of people (assuming they are all rational), and because of this fact, it therefore seems 'more true' or 'less wrong' ... bpyenson With Dickinson’s view it seems as if we’re living in a fantasy world constructed by our brains, which is fascinating to think of when writing science fiction or philosophy but I would like to think that what I’m experiencing is real and not something my imagination came up with ... fquadri i think that saying everything is a construct of our own brains gives us a more important role in the world than we really have ... hope How can something like morality simply be a result of firing neurons? ... shikha |
It would be nice to think that the world is almost magical in that my brain is creating what it wants ...Aybala50 I think our brains are complex enough to create complex emotions and our "inner mind." ... Leah Bonnell Dickinson’s idea, in conjunction with neurobiological information, may lead to a narrower, but more thorough exploration and understanding of the relationship between mind and brain. If we accept neurons and neurotransmitters as the basic mechanisms responsible for brain function, can we use these well-supported observations as building blocks to eventually comprehend the mind-brain relationship? ... kenglander So if we look at Dickinson the “the brain = behavior” we can start to look for some answers in the physical mass that is our brain ... ilja Without knowing the brain completely, I don’t think we can say that the dualism is right (or wrong) because the entity--the brain-- we are dealing with is not fully graspable. So, I would rather lean toward Dickinson’s view because that opens more possibilities ... redmink |
Start with overview of the "trend of the evidence":
- Behavior can be altered by altering the nervous system
- Traumatic brain damage
- Surgery, drugs, and ... ?
- Epilepsy as an instance
- Lots of aspects have behavior, even quite sophisticated ones, have "material" feel about them
- Surprising and quite sophisticated things can emerge from interactions of simple elements (of which the brain/nervous system is an example, as we'll see).
- It isn't that anything "disappears" as one discovers things related to
the brain but rather that the Brain gets "wider"
- Disadvantages?
- Advantages:
- ???
- would make the unobservable observable?
- Brain=behavior "True"? ("perhaps we just do not have the right microscopes yet"?). Good "story"?
- Are brains both sufficiently different and sufficiently similar to account for both differences and similarities in behavior?
- Do all things that influence behavior influence the brain?
- Is thinking a "physical" process? that can affect physical things?
- How do we distinguish between acting with and without thinking?
- Is morality/altrusim a function of the brain?
- Is "agency" a function of the brain?
- If everybody has their "own construct of what the world is" what follows from that?
- If the brain is itself a construction of the brain what follows from that?
- If brain = behavior, is all mystery lost? are there still "intriguing" things?
IF Emily et al are right:
- "brain"="nervous system"=body=matter, therefore all action/experience a function of organized matter? complexity from simplicity?
- Brains must not be only "reactive"
- Brains are to some degree different in different people
- Brains in given people must change with time/experience, must be affected by culture/language, nexus point for ALL influences on behavior?
- Brains must have different parts?
Some starting points: a sphagetti bowl? ("chains of neurons" or "hormones, chemicals")
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The sphaghetti (switchboard, "reflex") box
model
Virtues
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Sphaghetti (switchboard, "reflex") plus box
model
Virtues
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A rethinking - boxes in boxes
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The sphaghetti (switchboard, "reflex") box
model
Virtues
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Facing up to the stereotopy, stimulus-response problem ... freeing the box from the outside world, adding autonomy
| Harvard Law of Animal Behavior
"Under carefully controlled experimental circumstances, an animal will behave as it damned well pleases"
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The boxes inside boxes (with
"autonomy") model
Virtues
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If brain=behavior then the nervous system must not be a
stimulus/response machine (nor a bag of chemicals) that is invariant
and the same in everyone. It must instead be a different kind of "machine"
- somewhat different in different individuals,
- affected by both genes and experiences/culture,
- capable of
- different outputs for the same input
- taking in inputs with no output
- generating outputs with no input
- a "semi-autonomous" input/output box consisting of input/output boxes.
Go on to look at actual nervous systems to see if they satisfy expectations and to
address issues ... further iterations ("getting it less wrong") to come.
3 February
Issues for future consideration
Does our intelligence come from the presence of the “mind?” Do other, less intelligent creatures possess a mind, or do they only have a brain? ... bbaum
My pony has a lot of what I would term, common sense ... jrlewis
if this experiment were done with a human we would not be able to distinguish the signals coming from the brain as anything but just signals. Even if there was no body to communicate them would inner thinking still be going on? ... Sam Beebout
If the outside world is a construct of our mind, does this mean that a construct of the brain is controlling how the brain itself will act? It’s as if the brain as created a playground for itself, for which it can play in ... fquadri
we are in a a world where there is a box within a box within a box and then some. Our culture can be considered the mother of boxes, with all major inputs bouncing into us from our culture, and our reactions are to react within that box. sometimes our outputs stay within the box of the culture, and sometimes it bounces out. That way, our culture ends up effecting other culture boxes - which explains why nowadays there is a rise of anorexia in the eastern culture. That makes sense, doesn't it? ... hamsterjacky
in this model of the nervous system, there is NO foundational properties, there are no real built-in valuation systems of saying any aspects of the model are more important for its functioning than any other components. Maybe input is as equally valid as output. If that's the case, why can't we just switch the model on its head and make outputs inputs and inputs outputs, and see if the model holds 'true' then? .... bpyenson
I
too (like others before) like this idea of loopy science as I do the
idea of boxes within boxes as a representation for the nervous system.
Both offer a way out/around the set ‘rules’ that science is perceived
to be .... we
might soon abandon the input/output box model as we discarded the ones
before it and move onto a modification or a new one - one that has some
sort of explanation for contextual factors for indviduals
(culture,faith..), and also to keep the loopiness going ... mmg (see also kjean, ilja, drichard)
Immediate issues: boxes/outputs/inputs
It seems like the input/output box is favored by majority of the class. However, for me, stimulus/response model is still fine. Although I agree that input/output sounds more neutral and they add more complexity, I don’t have strong conviction to favor the input/output model yet. I think it is because I had been a strong believer who’s convinced that the function of the brain and behavior are solely based on chemical activity.So, it is hard for me to abandon my old belief, the concept of stimulus/response ... redmink
I've always been fascinated by the internal voice. What is it? How is it created? Obviously the internal voice doesn't have a specific input that leads to its formation, so it's created by one of the boxes within the box. But is the internal voice an output? ... Crystal Leonard
it seems to me that the essence of thought could really be compared to this box with no input signal ... Brie Stark (see also bkim)
It's not clear to me still how a box can produce output with no input, and vice versa ... Sarah Tabi (see also cc)
Now that we have a basic nervous system model as a reference I think we can confidently explore neurobiology and behavior ... Lisa B.
the boxes model still leaves open the possibility that there may be a metaphysical mind that operates outside of the physical. The boxes model has unexplained portions within the smaller boxes. How are inputs processed? What happens within the workings of the mind that creates and output, or not? ... eglaser
Even if you say all the way down, then what does the all the way down turtle stand on. What I'm trying to say is there must be a finite number of boxes that are within the larger boxes ... jwiltsee
how does this box model explain the recurrence of nightmares or images of traumatic experiences? How does the box model explain how we organize inputs once we receive them, and how we control outputs? ... nafisam
Since I am currently at a loss for how to investigate these boxes within boxes, I wonder if it is possible to explore the arrows that connect these boxes. Do they represent the neurons in the brain? ... kenglander
The "real" nervous system - an input/output box consisting of interconnected input/output boxes?
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| photo from Kemali and Braitenberg, Atlas of the Frog Brain, Springer-Verlag, 1969 |
Each box in turn (somewhat arbitrarily) subdividable into smaller boxes (with some differences among vertebrates, to return to)
And those ... yes, "its boxes all the way down"
The smallest box: neurons everywhere
Invertebrate nervous systems also have neurons, but differently arranged - makes sense?
Neuron as common, smallest box and as input/output element, connected to other boxes
- Cells, like other cells, but specialized to receive/process transmit "information" (as opposed to matter or energy)
- Size scale - tens of microns (10-6) meters)
- Larger boxes must differ in how smallest interconnected
- Relevance of numbers? enough to "account for all the uniqueness that exists among people"? ... 1012exp1012 possible nervous systems?
- Differences between people, differences between organisms due to .... not building blocks but assembly (architecture)
- Need to know how neurons work - to return to
Can use boxes->boxes ... ->boxes(neurons) to show that larger boxes interconnected, in relatively specific ways (anatomical specificity) and to rigorously specify "input" and "outputs" of largest box ... nervous system itself
- grey matter (soma, dendrites, pre-synaptic terminals, neuropil) vs white matter (bundles of axons, tracts)
- central vs peripheral nervous system (some ganglia, but largely axon bundles
- output elements of nervous system (motoneurons, plus) = neurons with axon terminating outside nervous system
- input elements of nervous system (sensory neurons, plus) = neurons with receiving surface (dendrites) outside of nervous system
- everything else = interneurons
- numbers/proportions: more reason to think of ns as "semi-autonomous"
So ... at least parts of our box within box model real ... and helps define "input" and "output" more rigorously
Implies: different regions on brain, different brains, different behaviors largely because of different assemblies of similar elements ("architecture")
The "real" nervous system - different if behavior different?
- Among different kinds of organisms?
- Among different individuals? within individuals over time?
- Notice that differences leave open the question of what causes differences (genes, experiences, activity, culture, etc)
- Implies that "information" can alter matter; not mysterious, "info" turns out to be perturbations of matter organization in neurons, can via metabolic processes influence organization/properties of neurons
10 February
From the forum
the brain is not a machine because we cannot always predict the outcome of a stimulus. But what about Psychology?... the whole point of my Experimental Methods and Statistics class is to design experiments and to critically examine data all in the ultimate goal of better understanding human behavior. I mean, isn't that what Psychology is about-- to understand and predict human behavior ... ? ... Anna Dela Cruz
I felt really great knowing that no one else had my brain. It made me think about this struggle for individuality that everyone has or certain people focus their entire lives on .... kjean
It would seem that since there are an almost infinite amount of combinations of neurons, which are each their own “computer”, that all humans would be vastly different, and any foundations, such as social norms, would not exist. Given the fact that they do exist, perhaps outside influences such as culture and social norms tend to even things out, and account for the similarities in behavior among specific groups of people .... nafisam
I do think that social and cultural influences or information shape the brains of groups of people. When people adapt a certain set of morals or certain way of thinking, they must also induce change in their neuron organization ... bkim
if the leach had been just freshly born when its nervous system had been removed, or if somehow a leach system was cloned and never put in a leach body would it still produce output? in more general terms, can a nervous system produce output in the complete absense of any previous input? If so, then what would be the purpose of learning other than to standardize the output of all of our brains? ... hope
could an individual alter the physical structure of his or her brain? ... ddl
Can you detect thoughts in the brain with an MRI? What is the physiology of a thought? ... eglaser
maybe thinking involves different parts of the brain, like the frontal lobe and temporal lobe, interacting with each other .... leah bonnell
At what point within the spaghetti web of interneurons does information go from unconscious to cortexual and conscious? - BeccaB-C
Our NS seems to be very complex and if it is responsible for our behavior, or can explain our behavior I think that maybe we have to look at some of the bigger boxes first ... ilja
The "real" nervous system - different if behavior different?
- Among different kinds of organisms?
- Among different individuals? within individuals over time?
- Notice that differences leave open the question of what causes differences (genes, experiences, activity, culture, etc)
- Implies that "information" can alter matter; not mysterious, "info" turns out to be perturbations of matter organization in neurons, can via metabolic processes influence organization/properties of neurons
Outputs - topographic organization - anatomical specificity
- Motoneurons located at levels of neuraxis related to location of muscles controlled
- Each motoneuron activates only one muscle
- Implications:
- "action" is not one output but pattern of activity across lots of them - "motor symphony"
- source of lots of additional variation in behavior
- lots of outputs/nervous system involved in any "action", is "distributed" characteristic
- need to understand how patterns of activity created, parts coordinated
- Sensory neurons terminate at levels of neuraxis related to location of receptors
- Implications
- "sensation"/"perception" not one input but pattern of activity across lots of them (across modalities and, as will be seen, in one modality - another "distributed" characteristic
- need to understand how inputs combined
- thought = pattern of activity across lots of neurons
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For additional information: |
Usefulness of the interconnected box model and ... another box?
- Capabilities of spinal cord
- Quadriplegia (slightly better) - relevance of topographic organization
- Christopher Reeves and ... , from NIH
- The "I-function"
Observations "surprising", but have to be accepted - Issue is "how to make sense of them"
Two kinds of behavior ("reflex" versus something-else) intuition probably not useful
- Spinal cord capable of very sophisticated activity
- Brain capable of quite unsophisticated activity
- Distinction between "reflex" and other things?
- "foot withdraws when irritated" - spinal cord capable of
sophisticated activity on own
- is ok ... given topography and "physical contiguity principle ("PCP")
- "person doesn't say ouch when foot irritated" - behavior frequently
depends on linking paths within nervous system
- is ok ... given topography and "physical contiguity principle ("PCP")
- "person doesn't move foot when hearing (or reading) request to do so" -
behavior frequently depends on linking paths within nervous system
- is ok ... given topography and "physical contiguity principle ("PCP")
- "person says foot irritation not felt/experienced" - behavior frequently
depends on linking paths within nervous system
- is ok ... given topography and "physical contiguity principle ("PCP") AND ..
- "behavior" can occur without it being experienced by the behaving organism AND ...
- neuronal circuitry adequate to support "feeling/experiencing" (I-function) is in the brain (spinal cord not needed for this function)
- Where is Christopher Reeves? Is he paralyzed? Does he feel pain? -
has to do with "mind", "self", "soul", "personality", "consciousness" ?
- words requiring redefinition in light of new experiences/observations?
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Ascending somatosensory
pathways Descending motor pathways
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If its all sensory neurons, motoneurons, interneurons, and signals moving among them (the I-function included), we need to look at signals, what they are, how they're handled ...
Signals:
- Resting potential
- Action potential
- Receptor and generator potentials
- Synaptic potentials
17 February
From the Forum
The fact that the parts of your body correspond to a certain section of the nervous system in an corresponding and relative manner never occurred to me. Nor did I pay much attention when I walked, talked, sat and stood about just how my body was accomplishing these requests ... SandraGandarez
thinking about an action and performing an action are different. Thoughts can be completely dissociated from inputs and outputs in the nervous system ... jrlewis
Could it be that autism is an anomaly, like the Reeves anomaly, of the I-function where somehow, some cords got tangled/cut/rearranged ... Brie Stark
I asked whether or not the "I-Function" is something used among neurobiologists or if the term/concept is just for the convenience of the class. I think it is important to understand where our class conversations intersect with the larger conversations that neurobiologists are having (see also Lisa B) ... We discussed the fact that the I-function is related to, but not the same as, the conscious/unconscious distinction, but I'm interested in learning more about where these two concepts overlap. In other words, if dreams are part of the unconscious, can they also be part of the I-function? ... jlustick
"I" am the focus of my actions, my actions are focused around me. Other people's perceptions of my personality is based on a series of actions that "I" am responsible for ... Sarah Tabi
it seems like the I-function is what we consider "self" ... Leah Bonnell
Which part of our body is truly essential to our individuality? And also, is there such a part? ... ilja
In order to reach a high level of competition, one must make the right action at precisely the right time. In a fast paced sport, such as fencing, these decisions are made in a matter of seconds.But at what point does the “I function” end, and muscle memory begin? ... Adam Zakheim
It was interesting to hear about the concept of pain being explained as a simple pattern of activity in one of the boxes of our nervous system. In our diagram of the system I would have thought it to be an input. After all, a person can percive pain without using their I-function. when a person burns their hand they withdraw the hand at the first feeling of pain, before the brain has time to register it. Does pain only be labeled pain if it is a part of the I-function? ... eglaser
maybe consciousness is simply being able to take in all the input signals from the environment and being able to potentially react to them. While the I-function is a part of consciousness--the part that focuses on thinking about how the "I" is going to interact with the environment. Perhaps the "I-function" fits under the larger umbrella term of "consciousness" ... bkim
for something as abstract and complicated as the I-function (a person's character, individuality, decision making), can just physical interactions between nuerons be held accountable? I find it hard to get my head around this divide ... mmg
The thing I'm still unsure about was in class we spoke about babies being different at birth and then converging to become similar in society. I think this is completely opposite. I believe that babies are very similar at birth, because they have no yet had the influence of society. I believe as individuals grow they diverge from one another, maybe not totally, but they diverge because of nurturing, society, morals, culture, and them just wanting to be different. This can swing back to the I function, where your individual self will make decisions and your mind will see things as it wants to construct them ... jwiltsee
For every unthinking action, is there also an identical set of neurons which allow that action to be regulated or produced within the constraints of the 'I' function box? Or is the 'I' function essentially able to tap into and oversee every other box within the human body ... ddl
If we were able to move the boxes required for walking lower in the nervous system, our brains may be able to accomplish more complex tasks because there is more room and energy for these tasks ... bbaum
Start with action potential, use it to raise questions that will lead to explanation of resting potential, use those ideas in turn to successively build up a set of more basic ideas that collectively account for all signalling.
- continual motion (diffusion)
- concentration gradients of charged particles (ions)
- specific membrane permeability
- passive current flow
- variable membrane permeability
Action potential - longitudinal battery which appears/disappears successively at successive points along an axon ("travels" at finite speed), "all or nothing" transient (millisecond range) event
- Helps to account for "thinking takes time"
- Is the common currency of "information" in nervous system cables (axons, axon bundles), of
all organisms
- Problem: how distinguish action from perception from thought?
- Solution: anatomical specificity ("see thunder, hear lightning")
- Is way to "see" otherwise unobservable
- Need to understand it - doing so will help make sense of other potentials, provide further insights into how ns COULD be behavior
To understand action potential, need first to understand resting potential - transverse battery, continuously present, with potential for continuous variation
| Organization based on random motion |
- Diffusion
- Selective permeability
- Charged particle movement, balance of diffusion and battery creation
- Stable
transverse battery, with potential for variation
- Concentration gradients, energy dependent ion pumping
- Can get action potential? what more?
24 February
The I-function
It now makes more sense to me why thinkinng sometimes makes me unable to do things. I'd always noticed that i couldn't do certain things, like driving or playing sports, if i thought about what i was doing, but i'd never thought about the reason. Maybe it is simply that thinking, or sending signals around in the "I-function", takes time, and when there isn't a lot of time the signals have to be sent directly to the muscles and skip the i-function ... hope
Now it makes more sense why I wasn't getting better, but worse for a while. Until I got used to the new routine, I was thinking about every step and because it wasn't more instinctual I wasn't playing as well. When I got a hang out the new moves, I started playing a lot better ... aybala50
I disagree that use of the I-Function impedes the execution of an act ... Olufemi.Nazsira
Action potentials: issues to keep in mind
Why is it that brain activity is so often portrayed as an electrical current when it is in fact a chemical one? It is interesting to note the inherent misconceptions about the brain that we must address. No electricity in the brain ... so how else has so called 'common knowledge' tricked us? ... eglaser
Do these chemicals and electric currents give rise to our thoughts and self-awareness as well? ... bkim
Is it just Sodium and Potassium that accounts for some of the best literature or art that is in the world today? ... mmg
It has often benefited me to look at the nervous system (and many other body systems) as a symphony of sorts. If all the individual instruments (the chemicals and proteins) play well, the body's song as a whole will be pleasing ... drichard
it is revealed that the girl has a rare genetic disorder which causes her to be insensitive to pain. Due to this insensitivity, the girl believed that she was a superheroine and often dared classmates to injury her ... Anna Dela Cruz
How much of this is in the hands of him/her? How much of experiencing pain is mental and how much is behavioral? ... BMCsoccer01
reaction time connects to the exercise we did in class where we proved through a computer program that it takes time to think. If thinking involves neurons, then it must also involve action potentials, which take time to travel ... Leah Bonnell
Whenever I've been close to stepping on something painful or running into something, I've always noticed the little delay before my body reacts to what I'm seeing. Instead of knowing that propagation is occurring and that all of these reactions are attempting to get me out of harm's way, I've always just thought that it was the surprise that caused my hesitation ... SandraGandarez
Issues to deal with more immediately
what would be the effect of two oppositely oriented action potentials moving into one another? ... ddl
Can action potentials move faster or slower? ... jlustick
Thinking of an action potential in this way can perhaps help explain how some input can have no output. If the cell membrane is not depolarized enough (ie it does not reach the threshold potential) an action potential will not be generated, it thus the input may not have an output ... shika (see also jwiltsee re pain)
We mentioned before that not all output boxes are connected to input boxes. Does that mean action potentials can be generated without stimuli? ... Sarah Tabi
Propagation
Notice it is NOT matter moving, nor energy, it is a perturbation (signal, information) |
Will propagate if started. How affect things? How started? Need to understand synaptic potentials, receptor potentials, but first ...
Lots of things can start it. Among them is something that provides answer to one of our box questions ...
And the big question ... Do signals actually start in the middle of the box? If so, how?
Yes, not mysterious, follows from what we know, if we add possibility of some differences in permeability of some membrane regions not mysterious, has interesting implications ...
- brain in a vat
- action without "personal responsibility"?
- epilepsy
- other things?
Go on to receptor potentials, synaptic potentials (how action potentials affect things, how boxes integrate, how signals stopped in box)
Input (sensory) signals - an example
- Neuronal receiving surface outside nervous system
- Sensory transduction - specific channels varying permeability in response to external events
- Receptor potential - continuously variable in space/time (like passive current flow
- Transformed into action potentials
- Coding in pattern of action potentials
- Significance for behavior?
- Restricted sample of "reality"
- All representations of "reality" in same form, in same signals as those created in nervous system itself
- Anatomical specificity IMPORTANT ("hear lightning, see thunder")
- Extra-sensory perception
- "five senses"?
- proprioception (muscle spindles, tendon organs, plus)
- pheromones
- others?
Synaptic potentials - Synaptic integration
- action potential vanishes at synapse
- intermediate chemical step: neurotransmitter release and ... (multiple control steps)
- permeability change leads to synaptic potential (alternate), also continuously variable in space/time
- summation - neuron as integrator rather than relay
- inhibitory synaptic potentials, algebraic summation
- is how to "stop" signals - significance for behavior?
3 March
Thus while we like to think of ourselves as individuals who are unlike any other person, we must also remember that our genetic similarities are what keep ultimately unite us ... kenglanderwe are all so different. None of us on this planet are made the same way. Then why is it that we are able to be treated by the same medications, same methods of healing? Why is it that there are manuals for how a person works such as the DSM or any science book for that matter? How is it that doctor's are so confident in their prescription of medication? I guess we can't be so different after all ... aybala50
We are all unique; we are all different. But our commonalities bring us together. ... Our symphonies are intimately in-tune with each other. The more we focus on the harmonius parts of the human song, the better off we will be ... drichard
it's interesting to see how our reality is limited. Sure we can see, touch, smell, taste, and hear but we lack receptors to sense gravity and magnetic fields ... It makes me wonder what else we are missing out on; what else is going on in the world that we are not completely aware of? Is it possible to find a satisfactory answer? ... fquadri
Could we, humans, in theory, have all of the receptor for 'all' stimuli? ... bpyenson
n class we talked about our conscious actions (the actions that go through the I-function) and our unconscious actions (actions that our NS is aware of but we are not). The examples were unexpected, we discovered another piece of ‘common knowledge’ that we take for granted every day (for example that we have 5 senses) without really thinking about what lies behind these assumptions ... ilja
Before class, I thought the only types of sensory receptors that existed were the basic five senses and as a result I couldn't really understand the article. In class we talked about how there are many sensory receptors beyond the five senses and that some of them are unconscious. Now I understand blindsight as one of these unconscious senses we discussed in class ... Leah Bonnell
The idea that we receive thousands of sensory inputs from the environment that we aren't aware of has helped me think about intuition ... Crystal Leonard
my intuition about my pony is informed by the sensory input I receive from her. This information is processed by my unconscious and crafted into a story that the I-function receives. This explains how I can know something without knowing how ... jrlewis
Let's take an infant or very young child for example who typically responds to fear by crying. Some infants may cry when any stranger enters the room, but others only cry when the person appears particularly "scary," the sort that might even instill trepidation in an adult. Is this fear socialized? Has the child, at such a young age, been trained to recognized certain aspects of one's appearance/body language as dangerous? Or is there something else allowing the infant to sense danger? Do dangerous individuals emit some sort of pheromone? ... jlustick
The fact that there are hidden receptors that do not pass through our I-function would provide a reasonable explanantion for how one woman has a different menstrual experience from another and why one woman is biologically labeled as the alpha-female and makes other females regulate onto her menstrual cycle. Are there any commonalities in alpha females socially and biologically in terms of their menstrual cycles and the receptors that their bodies encapsulate? ... BMCsoccer01
s it possible to have neuronal firings and physiological changes without cultural interpretation and the addition of meaning? ... kdillard
Could inputs produce inhibitory signals? ... bbaum
Synaptic potentials - Synaptic integration
- action potential vanishes at synapse
- intermediate chemical step: neurotransmitter release and ... (multiple control steps)
- permeability change leads to synaptic potential (alternate), also continuously variable in space/time
- summation - neuron as integrator rather than relay
- inhibitory synaptic potentials, algebraic summation
- is how to "stop" signals - significance for behavior?
Complexity of synaptic interactions
- Lots of neurotransmitters
- anatomical - e.g. presynaptic inhibition
- multiple steps in synaptic transmission - e.g. neurotransmitter inaction/reuptake
- use-dependence
- synaptic facilitation, depression, habituation, long term potentiation, heterosynaptic facilitation and Hebb synapses
- additional
indirect effects of receptor activation - e.g. neuromodulation, metabotropic synaptic activity
- signalling linked to cellular metabolism (an example, another)
- nervous system as continually evolving
- hormones, other materials, external agents (drugs, food, etc)
- "chemicals" can be an input/ouput, modulates "state" of network
- pharmacological as well as anatomical specificity
- we are not "bags of chemicals", but may be patterns of activity that reflect in part chemical neurotransmitters and can be modified by the chemical environment
- pharmacotherapy: rationale and limitations
Is the brain a machine? a computer?
- "salt running in and out of channels"
- multiple interacting processors
- combined analogue and digital processing
- use dependence, no clear hardware/software or processing/memory distinction
- both local and broad band signalling
- internal autonomy, randomness
- "I-function"? itself "salt running in and out of channels" (and therefore can affect other boxes)
- functions not visible in elements that appear because of higher level architecture
Problems solved, new issues raised ...
got inputs, outputs, boxes inside boxes
got signals starting in middle, ending in middle
got "I-function" as box
report of internal state
effect of external event on internal state
action based on internal state as opposed to simply external state or "causeless"?
issues of "self", "consciousness", "free will" not avoidable - if such terms didn't already exist, we'd have to make them up to make sense of studies on the nervous system ... "I-function" one way into them
got general sense of how smallest boxes work
integrators, with own contribution
anatomical specificity, local information transmission
pharmacological specificity, local and more global information transmission
modified by their own activity/function
implies all aspects of behavior/experience correspond to patterns of action potentials in neurons (modifiable by hormones, drugs, etc). Important "micro" base but also already some important "macro" understandings. Behavior/experience
involves distributed patterns of activity
changes due to its own activity
is sensitive to chemicals
does not always have an external cause
may be as much a function of inhibition as excitation
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