Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

Neurobiology and Behavior, Week 12

Submitted by Paul Grobstein on Tue, 04/14/2009 - 5:24pm

Welcome to the on-line forum associated with the Biology 202 at Bryn Mawr College. Its a way to keep conversations going between course meetings, and to do so in a way that makes our conversations available to other who may in turn have interesting thoughts to contribute to them. Leave whatever thoughts in progress you think might be useful to others, see what other people are thinking, and add thoughts that that in turn generates in you.

As always, you're free to write about whatever thoughts you add this week. But if you need something to get you started, what do you think of the idea that the picture in the head is an interaction among a number of brain regions, rather than localized at a particular place, and that you don't need it to "see"? What does a "story" of what's out there give you that you wouldn't have without it? And how does that relate to other manifestations of a "bipartite" brain?

Add new comment

Sleep Deprivation

Submitted by ddl on Tue, 04/28/2009 - 1:49am.

In my own experience, I tend to function well even after having minimal sleep the night before. However, my brother and several of my other friends are terrible when it comes to getting no sleep. What mechanisms account for the ability of some individuals to sleep less than others and still function with relatively unaffected performance as compared to others who require more sleep to effectively execute a given task?

Sleep

Submitted by OrganizedKhaos on Sun, 04/26/2009 - 9:57pm.

When I think about the topic of sleep and what goes on during the stages it is very interesting. I often times joke around when asked to wake up early stating, "i can't wake up that early, I'll be in my REM cycle." After learning about the different stages of sleep and dreaming it has become more interesting when looking at insomniacs and narcoleptics. What is going on in their brains?

Also I find it interesting how people can often change their sleep pattern. This is observed in college students as well as people who work night shifts. I have an older cousin who works night shifts and the idea that this could be doing damage to her brain and functionality is pretty scary. Is their no way to successfully change your sleep pattern and be okay?

What's 'brain damage' versus

Submitted by bpyenson on Sun, 04/26/2009 - 10:04pm.

What's 'brain damage' versus 'brain enhancement'? I think Dr. Grobstein would agree with me that those kind of statements are very context-dependent and relative.

Cosmetic Neurology in College

Submitted by bpyenson on Thu, 04/23/2009 - 12:26am.

Hey everyone,

I found this really cool article in the New Yorker that talks about cosmetic neurology, especially with stimulants (e.g. Adderall and Ritalin) at colleges (i.e the ivies).

http://www.newyorker.com/reporting/2009/04/27/090427fa_fact_talbot?currentPage=all

They quote a HC alum, Chatterjee at Penn, too.

Sleep Study in Drosophila

Submitted by shikha on Tue, 04/21/2009 - 4:18pm.

Our conversation about sleep has brought to my mind a paper I recently read about an experiment done on sleep in Drosophila. They kept Drosophila awake mechanically (I presume by shaking the test tube) and in one of the many experiments, used Western blots to determine the protein level in the brain. They found that the levels of proteins that are important parts of synapses were high if the flies were sleep deprived and low if they were not. Thus, the data suggests that sleep may play a role in maintaining a homeostatic balance of some synaptic proteins.

I wish they had done some cognitive tasks with the sleep deprived flies to see if sleep deprivation has the same effect on cognition and memory in flies as it does in humans and other organisms.

While it is not completely clear why sleep is so important, these studies (especially those done in mammals) can help get closer to the answer.

sleep

Submitted by aybala50 on Tue, 04/21/2009 - 10:53am.

I'm mostly interested in the idea of sleep. How much do we need it? Is it necessary? I'm a failure when it comes to pulling all nighters. I need my sleep even if it is at the cost of not getting my work done. How is it that some people can control this urge of falling asleep while I feel powerless towards it. What about dreams? I'm still not convinced in any concrete reason for why we dream. I feel like the dreams that I have that make sense to me, may mean something. But what about when I dream about things that don't have any meaning to me? Does this mean that they come from my unconscious? Does this mean they have more meaning that I give them credit for?

Moods as Language

Submitted by bpyenson on Tue, 04/21/2009 - 1:36am.

One thing that I was thinking about, especially as many people have posted concerning the neurobiology of mood in its role for perception is what about thinking of mood as language?

Much of language, at least according to some linguistics, is part of a subliminal system of signs in which the I-function shares no part. Instead, languages evolve undirected and spontaneously. Some of us can probably think of an example of language occuring without words (e.g. body language), but what about thinking about the variety of moods that we are bestowed with by nature in terms of signs that can be used to create an elaborate system of communication, not only with each other, but what about nature as a whole. If it is true that mood bears a role on perception, then couldn't our perception of nature (our reality) be translated to someone else in a pattern of moods (e.g more sad than excited, but more excited than bored)

If this is true and moods act as signs in a language, then couldn't our moods be more universal (shared) among each other than we would like to admit previously?

It seems to me that their is

Submitted by nafisam on Mon, 04/20/2009 - 11:25pm.

It seems to me that there is a direct relationship between the picture in our head, and the bipartite nature of the nervous system. When we look at an image, we process some aspects of it consciously, and some aspects unconsciously. Often times this unconscious processing of an image appears in our dreams. I have often had the experience of being in a lecture and taking notes, and when I go to sleep, I end up dreaming about a particular object that was in the classroom, but that I had not given any focused attention to during the lecture. I think this supports the notion of a bipartite brain because the neocortex and the cognitive unconscious both have processed the same set of surroundings, but have chosen which aspects are relevant during a certain period of time. Perhaps these trivial objects show up in my dreams because I finally have time to think about them.

I remember when I was in

Submitted by hlee01 on Mon, 04/20/2009 - 10:10pm.

I remember when I was in middle school I had the toughest time pulling an all-nighter whether it was for a sleep over or for an exam I needed to study for. As a college student, I have to pull all-nighters often and I have found them to be less painful/difficult for me to do compared to when I did them when I was younger. I'm guessing that sleep was more vital to my well being when I was younger since my body was developing.

How did I develop this routine of sleeping less? Will my brain develop more slowly compared to others' who sleep more (brains mature until we're 25)? What's going on in the nervous systems of insomniacs?

Some thoughts on vision...

Submitted by Adam Zakheim on Mon, 04/20/2009 - 9:23pm.

The idea that the picture in our heads is not located in a particular place in our brains, but is the rather the result of patterns of activity across the neocortex makes sense. The act of seeing involves a host of different neuronal signals that then require either conscious, or subconscious (or both) interpretation. Upon reaching the fovea, the image must be determined and isolated from several photoreceptor cells (cones and rods). This act alone involves multiple cortical visual areas within the neocortex, which takes this sequence of information and allows the brain to generate the picture in our heads. This sequence of neural networks, that begins with the retina, made me wonder about the existence of other types of vision.

In this sense, I do not mean to refer to the types of vision that result from structural defects in the eyes (such as myopia (shortsightedness), hyperopia (farsightedness) and astigmatism ( a misshaped, asymmetrical lens)). Rather, I’m curious about how the brain is able to precisely locate and distinguish one’s “objectivity” in reference to our environment. In my experiences with roller hockey, for example, it seems to me that players use three main types of vision; identification, association and peripheral. Identification provides the picture that allows one to determine the context and content of the environment. For example, this picture allows a hockey player to identify the puck from the floor. Subsequently, association with past experience allows the brain to take the picture produced by identification to locate the object with in the environment (depth perception, i.e. how close is the puck to the boards?) and thereby, allow for the generation of a proper response. Finally, peripheral vision provides a hockey player with yet another picture, which provides information about one’s immediate surroundings.

Since this picture from our head is the result of a distributive system, do these types of vision correspond to different regions in the brain? Moreover, how many types of vision do we actually possess with in our neocortex?

Why Sleep?

Submitted by fquadri on Mon, 04/20/2009 - 7:53pm.

Why do we need to sleep? It's a question that numerous people have raised throughout the years, and I tried answering it myself a few years ago through online research about sleep deprivation. I've always understood the purpose of sleep to re energize the nervous system by allowing it a break from the outside world. An example I can compare this to is a runner: A runner can only go so far and so fast without stopping for a glass of water to rehydrate him/herself. But here's another point: Runners at least can condition themselves to run faster or further, hence changing their initial set point. Can set points for sleep be manipulated? Can a person train themselves to where they can function on less sleep?
However I still see sleep as a way to give the nervous system some rest from the outside. Without it, the nervous system suffers. I've suffered from insomnia and sleep deprivation and this usually resulted in drowsiness throughout the day and inability to fully concentrate. The worst story I've heard is where a guy decided to not sleep for numerous days and towards the end of his ordeal, he started to have hallucinations that he was someone famous.

Mood Swings

Submitted by Percival52 on Mon, 04/20/2009 - 3:18pm.

Towards the end of our last class we briefly discussed how our mood influences our perception and ability. If we are in a good mood we might see the constant jibberish a toddler creates as cute and engage him in peek-a-boo. If we are in a bad mood those same sounds might drive us up a wall with annoyance and lead us to hush the child with a bottle or some other forceful way. I believe we talk about study early in the semester that analyzed a range of adults aptitudes when severely upset. The study discovered that across all groups, when enraged the ability to reason is decreased. This to me is further evidence of a bipartite nervous system. Personally there have been times when i have been emotional (really happy or angry) and acted in a greater risk taking behavior then normal but feeling that i was justified in do so. This to me means that even though I have an I-function, it doesn't unilaterally control my descision making. We also talked about the strong relationship between pharmacology and generalized control mechanisms. I am wondering about drug design. Do pharamceutical companies desgin drugs to depress the emotional parts of our brain or stimulate the moral rational sides to combat psycological disorders and diseases?

appreciation for sleep

Submitted by redmink on Mon, 04/20/2009 - 7:21am.

I completely agree with the idea that the picture in the head is an interaction among a number of brain regions, rather than localized at a particular place.

Indeed, It is our role to interpret the picture and apply it into our life. There are many steps by which we apply the picture into our life. One of the components we use is our mood. Depending on our mood, we see the world differently. Based on the mood fluctuation, there are various ways to interpret the same picture.

But what are the ways to enhance the positive point of view, that is, what's the way to keep the positive mood? One way i think is to have a enough sleep hours at certain time range. From my experience solid quality of sleeping from 10 pm to 2 am helps me a lot for my mood and brain function. I learned that it is 10pm to 2 am range in which most physical repair is taking place.

To enhance the assimilation of the picture created by bipartite brain into our life in more positive perspectives, having certain amount of sleep in the RIGHT TIME helps us make the picture more clear. During that time, the brain organizes/reinforces the materials we learned right before we fell asleep. Many studies report that that's why it is more beneficial to sleep before exam rather than pulling an all nighter cramming.

So, I think there is a strong relationship between sleep hours and mood fluctuation. My next question is how can people with insomnia deal with the mood fluctuation? How are their brain like?

Sleep, Subconscious, and Schizophrenia

Submitted by Anna Dela Cruz on Mon, 04/20/2009 - 4:24pm.

Professor Grostein asked in class why we sleep. Although his question was really asking for what causes us to sleep, I nevertheless thought about why it is important to sleep. His question immediatley reminded me of a sement on 60 Minutes that aired about a year ago called The Science of Sleep (link provided below). The exact answer on why it is important to sleep is still unclear. From an evolutionary standpoint, sleep seems counterproductive. When we plunge into a world of unconsciousness, we are left vulnerable to our surroundings. This suggests that the service sleep provides is far more important than being aware at all times. We can try to evade it, but we all know (perhaps through first hand experience) that lack of sleep comes with serious repercussions. Of the many studies featured on the 60 Minutes segment, one in particular has definitly resonated with me. This particular experiment tested the effects of sleep deprivation on emotional response. A control group that had received a full night’s rest was shown a series of increasingly disturbing images of blood, gore, mutilation, etc. The same procedure was followed for a group of sleep deprived subjects. Brain MRI scans of the control group showed constant and controlled activity in the imigdula, the emotional center of the brain. MRI scans of the experimental group, however, displayed hyperactive brain responses indicating a lack of control in processing information and then in generating an emotional response. Furthermore, scans of the frontal lobe, the region of the brain responsible for cognition, showed a pattern of activity among the experimental group that was similar to that found in patients with severe mental illness such as Schizophrenia. Is it possible that a lack of sleep can somehow interrupt connections between/among regions of the brain?

Although the exact cause of Schizophernia is still under investigation, studies such as the Hollow Mask Illusion Test suggest that the illness is caused, at least in part, by a disconnectivity between or among different regions of the brain. The Hollow Mask Illusion Test reveals that the spatial recognition and visual processing centers of the brain are not communicating in Schizophrenic patients and in the aforementioned mood study, these patients also exhibited such disconnectivity between the emotional and congnitive centers of the brain.

If processing information such as seeing requires the coordination between or among various regions of the brain, does this "checks and balances" system also apply to emotional responses? In my studies of Modern Art history, I have come across the Freudian theories concerning the id, the ego, and the superego. The belief is that the id is the emotional or irrational part of the mind located deep within the subconcious. The superego, on the other hand, is the moral and perfectionist part of the mind located in the consciousness and arising from societal conditioning. Both the demands of the id and the superego can at times be unrealistic therefore the mind requires the ego to mediate between the two--to find a way to get what the subconcious wants in a reasonable manner. In relating Freud's theories to neurobiology, could the id be seen as a lack of connectivity between/among various parts of the brain, the superego as too much communication of these regions, and the ego as the coordination of these parts? Would Schizophrenic patients have an overactive id?

The Science of Sleep

cones and colors and animals

Submitted by jwiltsee on Sun, 04/19/2009 - 8:07pm.

I was interested in how other species usually have 4 cones in their vision instead of three. The way I'm interested in it is that for many animals, such as frogs, we see them brightly colored to portray they are poisonous or animals that blend into things to avoid predators. If they blend in and are colorful to our eyes, how do they look to other animals with 4 cones instead of our three. Are they less or more defended???????

The picture in our brains...

Submitted by Sarah Tabi on Sun, 04/19/2009 - 7:22pm.

It makes sense that the picture formed in our brains are rooted from multiple regions in the brain instead of one localized place. It is a pretty ambiguous picture since we may look an image and form our own interpretation of what the picture is- especially when considering the pictures we looked at in class. In that respect, is there really such a thing as a "real" or "true" image if multiple individuals will perceive different pictures in their brain? How can one objectively be able to tell what the actual object looks like?

I don't think it is possible

Submitted by Bo-Rin Kim on Mon, 04/20/2009 - 1:34am.

I don't think it is possible to prove what an actual object objectively looks like. Color, and I assume other aspects of visual perception, are created in our brains, which makes it a unique experience for each person. I don't think it is possible to prove that the way I see something is the same way someone else sees the same object.

If this is the case for visual perception, I wonder if the brain also constructs the input we receive from our other sensory perceptions (i.e. taste, hearing, etc.). For example, when I hear something, does it sound the same to someone else? Or is it like color where we each have our unique perceptions of the sensory stimuli?

I agree that it's probably

Submitted by BeccaB-C on Mon, 04/20/2009 - 10:15pm.

I agree that it's probably not possible to objectively know what something looks like/what color it is "in reality"--at least until we define reality. In class we spent a while talking about there not being a reality at all, and yet we continue to say that we don't know what colors "really" look like. If real and reality don't exist, we can't be defining things in these ways. I move to define "reality" as the world that human's interact in and percieve collectively. Those aspects of the world (inter-personal perception of colors, actual wavelengths, shapes, corners, parts made up to fill blindspots, etc.) are then not part of this "reality" and so we cannot know for sure what the collective human experience of them would be.

My recent web paper dealt

Submitted by drichard on Sun, 04/19/2009 - 2:14pm.

My recent web paper dealt with the brain's aesthetic appraisal system. It got me thinking out neurobiology as a field of study. It is interesting to think of neuroscience as a type of meta learning. In other words, by studying our brains (through neurobiology or psychology) we are learning about learning as the brain is the seat of all knowledge.

Continuing in this vein, I think it is important to remember that all knowledge belongs to humanity; that all knowledge starts in the brain. Philosophically speaking, this is an empowering aspect of our reality. Also, it encourages interdisciplinary studies like that or neuroesthetics (the study of the brain's aesthetic appraisal system which brings together neuroscience, art, and empirical aesthetics).

I was also thinking about the brain's "story" this week. As opposed to a cut and dry, computer-like observation system, a story gives your reality meaning. It allows the human being to see purpose and to derive direction from what it is perceiving. This is another empowering aspect of our reality.

waking up happy

Submitted by Sam Beebout on Sun, 04/19/2009 - 12:44pm.

Our talk about whether or not sleep is beneficial reminded me of a section of Jonah Lehrer's Proust Was a Neuroscientist. The book has received a lot of criticism for the leaps Lehrer makes between science and the arts, but I think Lehrer's aims apply well to what we are doing in this course.

Lehrer talks about the role of sleep in the process of neurogenesis, which is the process of creating new neurons in the brain. Neurogenesis is a newly accepted observation among neuroscientists because it overrides the popularly held notion that our brains are fixed. Lehrer notes that neurogenesis is encouraged by sleep and suggests that our brains are a little different each time we wake up.

Interestingly, neurogenesis studies that have been done have observed that neurogenesis is strongly linked to a positive mood. Neurogenesis, and the activities that promote it (learning, exposure to new things, sleeping), do the same work as an anti-depressent.

Sleeping too much versus not sleeping enough can profoundly effect a persons mood, which ultimately effects who they are as a person. Why do we get grumpy when we are tired? Conversely, why do people who are depressed sleep all the time?

Mood Fluctuation

Submitted by Leah Bonnell on Sun, 04/19/2009 - 11:10am.

I am interested in the idea that mood fluctuation provides a more complete view or perspective. In class we discussed the how different moods allow us to perceive a cat, for example, differently depending on mood. This idea makes sense to me as it gives some explanation as to why moods evolved. In a larger sense, I think awareness of the benefits of mood fluctuation can help us become better adjusted individuals. If we understand that sadness has benefits, we can become more appreciative of a sad mood and of mood fluctuations in general.

I think it is completely true that mood affects our perspective, even in the most basic sense. If you were to ask a sad person if a glass was half full or half empty, their mood would most likely literally change the way they saw the cup. Based on this, I think the simplest way to define depression, is as chronic intensely sad mood. In other words, as a result of the lack of mood fluctuation, a depressed person can only see the "sad" perspective.

Week 12

Submitted by Lisa B. on Sun, 04/19/2009 - 9:28am.

Scientists believe sleep is necessary for our nervous system to function, and that sleep allows some neurons to repair themselves (NIH). These researchers used an animal study to show that several nerve-signaling patterns produced during the day recurred during sleep, and that this pattern may help improve learning. Together with test-anxiety, this study probably accounts for my strange dreams before a Spanish exam where I would review vocabulary. This extra preparation might have improved my Spanish grade, but the sleep deprivation caused drowsiness and I would sometimes miss questions. Before exams, I now clear my mind before sleeping with a book and leave my radio on throughout the night. After nights of too little sleep, I now understand the NS consequences of drowsiness, decreased concentration, and impaired memory.

Sleepwalking/hypnosis/dreaming

Submitted by jlustick on Sat, 04/18/2009 - 2:48pm.

Can the experiences that an individual has while sleepwalking be uncovered through hypnosis? How is hypnosis different than sleep and the trance-like state one is in while sleepwalking? Do sleepwalkers respond to individuals in the way a person would while being hypnotized? With hypnosis, there is a question of who has control over the subject's body, so is the same true for sleepwalking? Is an indivdiual in control of her body while sleepwalking or can another individual control her?

Also, how are dreams and our sense of self related? Is what happens in our dreams a product or our sense of self, an influence on our sense of self, or both? Can who we are in our dreams change who we are when awake and vice versa?

sleep walking

Submitted by SandraGandarez on Fri, 04/17/2009 - 8:13pm.

When we discussed sleep walking we talked about how the person acts as they would if they were awake. They also have their eyes open (in most cases I'm assuming). If all this is happening isn't it safe to assume that there is some sort of input (from eyes, ears and touch) and output (walking, eating, driving, etc.)? Since I feel like there is an input and output for a person is sleepwalking I do not completely understand where all the information goes. They do not remember these nightly jaunts but they performed them, their brain was active for them, so where did the information go? Do they have an unconscious knowledge of what they did and are unable to access it? I don't entirely understand how this works when the brain is involved. It counters certain things we have already learned during the semester about the brain and its activity.

Might Horses Have a Theory of Mind?

Submitted by jrlewis on Fri, 04/17/2009 - 5:07pm.

Earlier this afternoon, I was standing with my horse Bailey and chatting with my trainer. She reached out and tapped my horse on the neck with her fingers. My mare responded by bending her head and snapping her teeth, where the woman’s finger’s had been. This surprised both of us humans, it is an uncommon reaction for a horse to have. My trainer, then tried squeezing her on the other side of the side of the neck and we observed the same snapping teeth. A normal horse would have responded to a touch on the neck by either lunging forward and biting the offending human, or back up/away from the human (the correct response). The average horse would have been capable of attributing the sensation in their neck to human fingers and the human standing in front of them. They could connect a tactile input to a visual input and derive a story about the intentions of the person standing in front of them. That the person was communicating to them that they should back up. Bailey, didn’t connect the tactile sensation to her visual input of a person and their hands. Instead she interpreted the touch as an attack from another creature than the human, hence the biting at the hands. It appears that Bailey may not have as fully developed a theory of mind as other horses.

extreme moods

Submitted by eglaser on Fri, 04/17/2009 - 7:58am.

I wonder why mood is so dependent on so many factors in order to form one emotion. It seems that mood is variable based on how you yourself want to feel, what medicines or other substances you are on, and your environment. Why would this be? I know we discussed this and decided that it allows you to see things from a new perspective but, what evolutionary value could that have? If you look at a tree when your happy versus when you are angry it is still the same tree.

Also, I wonder if we can discuss what happens with more extreme mood changes like severe depression or mania. Is it solely based on chemical alterations in the brain or is there and I-function/ environmental element to the creation of these problems?

We briefly brought up

Submitted by Brie Stark on Thu, 04/16/2009 - 11:26am.

We briefly brought up sleep-walking at the end of class, but I was also wondering about sleep-talking. I am a notorious sleep talker (or so I'm told, seeing as I remember nothing about the occurrence) and therefore wonder if there are parts of my "self" in the jumble of words that I mumble every night. I know we said that sleep-walking does involve the I-function, but one usually has no memory of the occurrence--how does this happen that we remember dreams if woken up during the REM cycle (or Delta cycle?), but not sleep walking if done during the REM cycle? I have the same question for sleep-talking.

I also got to thinking that, if one is lucidly dreaming, one has to have a balance between a sense of "reason" and a sense of "emotion." The "reason" would be seeing delusions--which the brain probably wouldn't favor--but the emotions would be the desire to continue seeing those delusions. It seems to be a push-pull sort of relationship occurring in the brain when this happens.