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05. Mind and Brain

        Neuroscience and cognitive psychology are making important developments in showing how people think and learn.  There are some fads, such as "left" and "right" brained, only using 20% of your brain, which are unvalidated and shouldn't be trusted.  Theoretical positions that should be trusted come from the convergence of evidence from developmental psychology, cognitive psychology, neuroscience, and more.  Neuroscience evidence comes in large due to PET and FMRI technology.  Three main contributions have been that learning changes the physical structure of the brain, structural changes alter the functional organization of the brain, and that different parts of the brain learn at different times.  
        The brain physiologicall is made of neurons with dendrites and synapses.  The wiring diagram, or synapses, of the brain are only 33% formed at birth, a proportion of which is guided by experience.  Synapses are the connecting point where information is transfered between neurons.  One form of synapse production is like a sculpture - many synapses are formed at first and slowly chisled away and refined over time, from 2-3 and sometimes 8-10 years.  Synapses are also added over time, being driven by experience.    
        Brain wiring is illustrated well with eyes, which develop independent inputs to the brain at first, converging in the visual cortex.  Studies of people who lost sight in one eye either during or after childhood, when the wiring was being formed, shows that during a critical period the wiring happens and gives the eye it's functions.  After synapses are overproduced and refined, there are still changes that happen to the wiring.  Research suggests that learning modifies and even creates new synapses. 
        Experiences and environments affect brain development.  Animals raised in complex environments, for example, have a greater volume of capillaries per nerve cell.  Weight and thickness of brains in animals also change when put in more "academic" environments (such as with different toys where they can explore).  These animals also perform better on problem-solving tasks.  Having a social context contributed too.  
        Studies with rats showed that physical activity and learning influence different parts of the physical structure of the brain.  In one experiment, exercisizing rats developed more blood vessels in their brains, while thinking rats developed more synapses per neuron.  Thus, different types of activities condition the brain in different ways.   Moreover, structural changes in the brain are localized depending on the task.  For example, rats that learned mazes had structural changes to the visual area of the cerebral cortex, whereas rats that learned complex motor skills developed in the motor regions of the cortex.  
        The type of information that is stored in the brain is the job of cognitive scientists.  There is a plausibility that language develops similar to the synapse overproduction method, as young children can here the difference between all phonemes, but after learning their lanuage they lost that ability to distinguish.  The fact that synapse elimination occurs at different rates at different parts of the brain suggests that there is a timetable to learn certain things.  
        Language is a particularly robust area of research converging cognitive science and neuropsychology.  There appear to be separate brain sections for different subtasks in language (e.g. reading, speech, thinking with language).  Deaf people provide insight, as sign language requires an altogether different neuronal pathway than auditory language, yet the brain still succeeds in connecting the language part of the brain to the necessary form of communication.  Deaf people who use sign language and/or become deaf later in life further provide information on brain wiring and reorginzation.  Patients with brain trauma or impairments similarly shed light.  
        PET and MRI studies come in two forms for memory - on the lack of a unitary construct, and relating features of learning to effectiveness in recall.  The lack of a unitary construct is shown by the fact that declarative memory (facts and events) is stored in the hippocampus, while proceducral (skills or cognitive operations) in the brain system involving the neostriatum.  As for effectiveness, research shows that memory of pictures is better than that of words. 
        Research also shows that the brain actively organizes information.  In one study, people are given a list of words.  During the recognition phase, subjects reliably remember words not on the list if the word helped them organize the listed words.  Thus, the fact of "experience" become important, as implied and/or wrong information also is stored in the brain, and further research shows that people become convinced thse are true memories after some time.  
        All these points about memory are important to understanding learning.  Mind imposes structure on the information available from experience.  Neuroscience confirms this claim.  In short, the brain is a dynamic organ shaped to a great extent by experience.  
        For key points summarize this chapter: 1) The functional organization of the brain depends on experience; 2) Development is not just biologically unfolding, rather it is an active process; 3) There are certain sensitive periods where learning can have the most effect; 4) The relation of these discoveries with education needs more care and attention.  

THINKING ROUTINE - HEADLINES

This routine draws on the idea of newspaper-type headlines as a vehicle for summing up and capturing the essence of an event, idea, concept, topic, etc. The routine asks one core question:

1. If you were to write a headline for this topic or issue right now that captured the most important aspect that should be remembered, what would that headline be?

Experience Alters the Brain

A second question involves probing how students' ideas of what is most important and central to the topic being explored have changed over time:

2. How has your headline changed based on today's discussion? How does it differ from what you would have said yesterday?

I didn't quite appreciate the extent to which the experience can alter the brain through synapse modification, nor did I know about the idea of synapse elimination, which provides a useful metaphor for how we may have critical periods of learning.  As a result of the first point especially, I wouldn't have been so confident that the brain is really modified by experience.  All of this confirms many beleifs that I have about experience adding sophistication to the brain.  Certainly on this general level one can see how discoveries in neoroscience promote an education where students are active.   
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