Biology 202 Neurobiology and Behavior Spring 2004

Also, as a right-handed person, I'm also pleasantly surprised when I meet a left handed person. From my experiences, they seem to have completely different processes of comprehension than those who are right handed. I know this occurs because each side of the body is connection to an opposite lobe, but what are the differents within these lobes that explain why left and right handed people think and act differently?

Lastly, did you notice we have people out of Bryn Mawr/Haverford commenting? Impressive, I think we're asking the right questions.

Actually, you are wrong. Chiildren learn language implicitly, without working on it, and with many other responsibilities, such as learning social skills, interacting with peers and family, etc. And studies have been done, showing that children learn language MUCH better than adults, to the point where "responsibilities" couldnt be what is causing the difference.

In an attempt to get it less wrong, I searched online about children and adult second language acquisition, and here's what I found:

http://www.ntlf.com/html/lib/bib/87-9dig.htm

http://www.ericfacility.net/databases/ERIC_Digests/ed350885.html

These summaries suggest not only that adults and children have same potential for learning foreign languages, but that adults actually have an advantage. Of course, these summaries are in no way conclusive or exhaustive (I think I see a web paper topic emerging here :) ), but I just wanted to quickly check if my gut feeling (and I'm a non-native English speaker myself) is shared by anyone else. Again, I'm not saying that this HAS to be true, but my own experience and the experience of people I know suggests that learning potential (and that goes for languages) does not decrease, but increases with age. Now, I admit that saying that a child has fewer responsibilities was not the most convincing way to account for this. But I think that if one looks at it in terms of developmental growth (both conceptual and structural), it makes a lot of sense. But I'll keep working on this :). That's why I like this forum, it makes us all think more (and learn more).

On another topic, i dont think it is dangereous to learn about our own brains. In what way do people think it is dangerous? It is important to learn about our brains to better understand human behavior.

And about language- I didn't know that studies had shown adults as as capable (or more so) of learning language. that is a good webpaper idea, i thought the opposite, and all I've read before thought so too. Maybe there's hope yet for me to learn a language really well!

So: Are the rewired ferretts "hearing" light rather than "seeing" with their auditory cortexes? Or are these the same thing? Is this what happens in the brains of people for whom sound has color or words have taste? We probably won't ever know how the rewired ferretts experience light, because 1) input does not equal experience, so we can't make any assumptions, and 2) the ferretts can't tell us what they experience. But even if we could do something like this in humans (ignoring, for the moment, the ethics of such an experiment) would the subject be able to tell us about his experience? He wouldn't know anything different, so how would he put it in terms we would understand? It would be like trying to describe color to someone who is congenetically blind. So we would have no way of knowing if he "saw" as we do, or if his "visual" world were a myriad of sound instead. And this, this not being able to know, is just as fascinating as the rewiring.

Basically, the idea behind Schrodinger's Cat is that reality is dependent on conscious observation. Which has a lot of very interesting and very strange implications about consciousness and reality both. All reality (according to the theory) exists as simple probabilities, until it's been observed- and the act of observation collapses the probability wave and decides which reality is... "real", I suppose. Decides which of the probabilities becomes the actual state of reality. Which can make your head hurt if you think about it too long. I'll give the example that my friend gave me. First you take the actual thought experiment, of Schrodinger's Cat. It's not an actual experiment- it'd be awful if someone actually did this to a cat, but it's just something to think about. You take a cat, and put it in a box. And then you set up conditions so that there's a 50% chance the cat will live, and a 50% chance the cat will die. However, the experimenter won't know whether the cat's alive or dead until she looks into the box. The idea according to this theory, though, is that the cat is neither alive nor dead until someone goes over to the box, looks in, and consciously observes that yes, the cat is alive (or dead). The cat is in both states- the reality in the box is in both states- until it's been observed.

That in itself is a little hard to digest. But then, say you take it one step further. Say that the experimenter herself leaves the room for lunch or whatever, and realized that oh! Someone has to go check on the cat! So she asks someone else to go check on the cat and see if it's alive or dead. However, she herself won't know whether the cat's alive or dead until the person gets back. She won't know what that person has seen. Nobody knows what that person's seen. So that second person also exists in two states until he/she's come back and told the experimenter that the cat is alive or dead.

And another implication of this theory is that if a tree falls in the forest, with no one around, there is no way to know whether it made a sound or not- not just because no one was there to hear it, but also because its reality will exist as probabilities unless someone's there to consciously observe it.

My friend ended his letter with, "This is one of the reasons physicists sometimes end their days in lunatic asylums."

actually, the area of the brain corresponding to the amputated body part is still stimulated, even though there has been deafferentation corresponding to that body part and thus a lack of sensory imput. for example, many of the early studies on phantom limbs we performed on monkeys whose limbs and digits were amputated by experimenters. in one ground-breaking study, it was shown that when a monkey's middle finger was amputated, touch stimuli of adjacent digits led to demonstrable stimulation of the cortex corresponding to the amputated digit.

"Other corresponding parts of the body represented in the brain may then be able to expand into the area of the finger.Conclusions drawn from this would include that applying pressure to other parts of the body could illicit a response in the phantom limb"

phantom limb studies have provided evidence that has convincingly demonstrated the plasticity of the adult brain in terms of remapping of the somatosensory cortex. for example, several studies have shown that due to the way in which the somatosensory cortex is organized in primates (i.e.,including humans), when a person has their arm amputated, touch stimulation of their lower face region results in sensations or pain in the missing limb. this is the result of cortical organization, which makes perfect sense when we remember that accordingly to the somatosensory map (commonly known as the homunculus), the area of the cortex corresponding to the face is directly adjacent to the area corresponding to the hand/arm region. interestingly, the receptive fields on the face are both distinct and differentiated in terms of the digit/area of the limb with which they correspond. in other words, in one study of 2 right upper arm amputees, sensory stimulation of particular areas of the face, corresponded to particular digits in the phantom limb (e.g, the pinky finger, the thumb, the middle finger, etc.).

Is the sensation that people who are amputee's have similar to that of one's arm falling asleep? What effect does the sight of a limb, or no limb at all have on sensation? I can remember one experience of waking up, and having a prickling sensation in my arm, but as I looked down onto my arm, I had no sense of it being connected to me as a whole. Why would something like this occur?

Certain parts of the body can be stimulated to get reaction for another area/part of the body. In the case of sciatica, the diagnosis is usually given when the patient complains of stinging pains or sensation occuring when moving the shoulder. Could this movement of sensation also relate to phantom limbs, as stimulation in a certain area of the body once connected to the area amputed result the in nerves there producing an electrical stimulus, thereby creating possible sensations of phantom limbs?

As for languages, is there a point where the brain cannot process any more different languages, thus limiting how many we can learn?

Some theories suggested it came about as a result of natural selection, or the development of certain parts of the brain (Broca's areas and Wernicke's), or the discovery of FOX2P (the "speech gene"). The theory that I found particularly intriguing is that speech is arguably a motor activity rather than an oral exercise. By motor activity we mean the movement and coordination of the face, mouth, larynx, tongue, breath and cognitive activity. Sign Language, or a primitive form of it can be thought of as an "intermediate behavioral manifestation" between animal communication and speech. Clearly, we must redefine what we mean by speech: is it primarily oral or motor? What do we mean by oral and motor? One of the first steps we can take is to look at languages across cultures and see how predominant gestures and facial expressions are in conjunction with the spoken word: can the two be separated?

If we follow the motor theory further...the basal ganglia, which is responsible for movement, acts as a "sequencing engine" that makes the combination of verbal and gestural possible. The concept of imitation came up as one process that enabled the evolution of human speech. By imitating gestures and speech sounds, and incorporating these observations into our own behaviors, what does this suggest about language as an innate ability?

Also, going along with the learning string, would it be horribly provocative to say that imitation and learning are the same thing? Going back to brain=behavior, since the brain contains the ability to imitate (something which is something external from the brain), doesn't this complicate the relationship between brain and behavior?

I wanted to add to Brad's comment about neural connections and learning. In the Cognitive section of Intro to Psych, we looked a lot at Memory, Learning and Retrieval. I think that approaching this huge and complicated topic of learning would be of greater significance if done from different disciplinary points of view at the same time (Bio, Neuro, Psych ...etc). For example, in Psych class we talked about the NeuroMuscular Theory, which says that mental practice activites the same patterns of neuro-muscular pathways as the actual physical task. As you know, mental practice has indeed been proven to be effective (and some coaches still use it to train their teams). This is just to give you an idea of how rich and complex the processes associated with learning can be ...

(By the way, I'm a big believer in the Liberal Arts, and that the different sciences or disciplines complement each other).

What's the point of confirming our experiences of reality to be Real (or convincing ourselves that it isn't, for that matter)? Truth is messy. If truth or reality is individual and subjective—as cases of phantom limbs might suggest, for example—it seems that there is at least some support for no one in particular's concept of reality to be true. Any one of us could have it wrong, and there is no Deus ex Machina, no final arbitrator to tell us who has it right. If one person can have reality wrong, than any/all of us could, too; and where is the usefulness of a concept of a True Reality to which we cannot be sure any of us has access?

Both of the posts I mention appeal—at least in passing—to interpersonal interaction as maybe providing an answer, and I think they may be right. If we think of reality as a learned social norm built over time and not as The Way The World Is, it makes sense to speak of what is real and what is not. People and places and things are real because a lot of people think so; it is how we have come to structure our world and our social understandings of our perceptions. The mentally ill or paraplegic or whoever seems not to be in agreement is out of luck: s/he can define reality as s/he likes, but the majority of us aren't going to go along with it.

If we can understand reality as a constructed narrative, and not as some external entity to be "discovered" with our unreliable and stubborn and easily fooled senses, then we have more leeway in deciding how we understand reality. For example, how do we know what is really real and what is not? Real is what we've all agreed to. What would be the point of deciding our currently understood reality needs to be altered? To fix the narrative to be richer, more useful, etc.

In trading an external reality for a self/socially constructed one, we trade uncertainty for flexibility. In this conception of reality, we can't know that we are right, but who cares? We can't know if we are right thinking of reality as external or fixed either.

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