In considering which findings from brain research are relevant to human learning or, by extension, to education, one must be careful to avoid adopting faddish concepts that have not been demonstrated to be of value in classroom practice. Among these is the concept that the left and right hemispheres of the brain should be taught separately to maximize the effectiveness of learning. Another is the notion that the brain grows in holistic "spurts," within or around which specific educational objectives should be arranged: as discussed in this chapter, there is significant evidence that brain regions develop asynchronously, although any specific educational implications of this remain to be determined. Another widely held misconception is that people use only 20 percent of their brains--with different percentage figures in different incarnations--and should be able to use more of it. This belief appears to have arisen from the early neuroscience finding that much of the cerebral cortex consists of "silent areas" that are not activated by sensory or motor activity. However, it is now known that these silent areas mediate higher cognitive functions that are not directly coupled to sensory or motor activity.
Some neuroscientists explain synapse formation by analogy to the art of sculpture. Classical artists working in marble created a sculpture by chiseling away unnecessary bits of stone until they achieved their final form. Animal studies suggest that the "pruning" that occurs during synapse overproduction and loss is similar to this act of carving a sculpture. The nervous system sets up a large number of connections; experience then plays on this network, selecting the appropriate connections and removing the inappropriate ones. What remains is a refined final form that constitutes the sensory and perhaps the cognitive bases for the later phases of development.
This phenomenon only occurs if an eye is prevented from experiencing normal vision very early in development. The period at which the eye is sensitive corresponds to the time of synapse overproduction and loss in the visual cortex. Out of the initial mix of overlapping inputs, the neural connections that belong to the eye that sees normally tend to survive, while the connections that belong to the abnormal eye wither away. When both eyes see normally, each eye loses some of the overlapping connections, but both keep a normal number.
In the case of deprivation from birth, one eye completely takes over. The later the deprivation occurs after birth, the less effect it has. By about 6 months of age, closing one eye for weeks on end will produce no effect whatsoever. The critical period has passed; the connections have already sorted themselves out, and the overlapping connections have been eliminated.
After the cycle of synapse overproduction and selection has run its course, additional changes occur in the brain. They appear to include both the modification of existing synapses and the addition of entirely new synapses to the brain. Research evidence (described in the next section) suggests that activity in the nervous system associated with learning experiences somehow causes nerve cells to create new synapses. Unlike the process of synapse overproduction and loss, synapse addition and modification are life-long processes, driven by experience. In essence, the quality of information to which one is exposed and the amount of information one acquires is reflected throughout one's life in the structure of the brain. This process is probably not the only way that information is stored in the brain, but it is a very important way that provides insight into how people learn.Very young children discriminate many more phonemic boundaries than adults, but they lose their discriminatory powers when certain boundaries are not supported by experience with spoken language (Kuhl, 1993). Native Japanese speakers, for example, typically do not discriminate the "r" from the "l" sounds that are evident to English speakers, and this ability is lost in early childhood because it is not in the speech that they hear. It is not known whether synapse overproduction and elimination underlies this process, but it certainly seems plausible.
Experience in environment for brain development
Neuroscientists have investigated how the visual-spatial and language processing areas each come together in a different hemisphere of the brain, while developing certain new functions as a result of the visual language experiences. In the brains of all deaf people, some cortical areas that normally process auditory information become organized to process visual information. Yet there are also demonstrable differences among the brains of deaf people who use sign language and deaf people who do not use sign language, presumably because they have had different language experiences (Neville, 1984, 1995). Among other things, major differences exist in the electrical activities of the brains of deaf individuals who use sign language and those who do not know sign language (Friedman and Cocking, 1986; Neville, 1984). Also, there are similarities between sign language users with normal hearing and sign language users who are deaf that result from their common experiences of engaging in language activities. In other words, specific types of instruction can modify the brain, enabling it to use alternative sensory input to accomplish adaptive functions, in this case, communication.
From these findings, it is clear that there are qualitative differences among kinds of learning opportunities. In addition, the brain "creates" informational experiences through mental activities such as inferencing, category formation, and so forth. These are types of learning opportunities that can be facilitated. By contrast, it is a bridge too far, to paraphrase John Bruer (1997), to suggest that specific activities lead to neural branching (Cardellichio and Field, 1997), as some interpreters of neuroscience have implied.
Questions:
Does the concept of synapse creation and destruction support the ideas of "people can't change" or "you can't teach an old dog new tricks?"
Have people with abnormnal psychological tendencies (depression, mania, pedophilia etc) perhaps "learned" the wrong way?
Say for instance a young child witnesses his mother die a long a painful death. When that child is so effected by this tragedy, he resolves to one day become a Doctor to help people who are undergoing the same anguish as to fight the injustice in his heart. Almost like Bruce Wayne I guess in Batman - witnesses his parents get killed during a mugging and one day assumes the role of an above-the-law vigilante. Does the effect of synapse and memory/cognition have an effect on people who have experienced some sort of trauma? What about people with other psychological complexes? (Oedipus, Medea, Peter Pan, Bruce Wayne, etc) I know this might not directly deal with the aspect of teaching but it makes me wonder about things like this in general about what we learn to be reality......
Opinions:
This chapter was pretty enlightening. The sculpture reference really makes it clear to me (and not just because i am an art major.) Seeing that analogy put together with the concept of language development in children vs. adults is pretty fascinating.
Adaptive functioning was also a cool idea. It made me think of Bats because of their use of sonar to gauge distances.
Blood vessel development in brains for active creatures was an interesting idea as well. I am to learn that considering that I have heard random school subjects get spurned as "useless". Even I am at a weakness in my conceptions of Mathematics, where as I am good with writing, reading and creating, I cannot by any means bear math. And at a young age when I decided I hated it and it was useless, I guess I let learning the abstract concepts of math go completely. I always wished I could but now that I am taking this course I wonder if, perhaps, I was not exposed to the right form of instruction? I wouldn't dare say I wasn't partly to blame, heh heh.
Synapse pruning and modification were really the biggest reveleations for me to have in this chapter, mainly because it supports ideas of the freshness of young minds and the ability to learn (or re-learn) based on your experiences.
Overall, I am interested to be learning about the way people learn.
On my last note, I have always believed and told myself that "change comes from within." Change doesn't always happen because you want it to either... I guess you have to wait to be inspired sometimes.
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