Overview

– Brain• Development• Macroanatomy• Microanatomy• Plasticity

Brain - Gross Anatomy1/3

• Basic subdivisions– Spinal Cord– Brain Stem– Cerebellum– Cerebral Cortex

• Conscious thought• Planning• Language

Adult Brain - Gross Anatomy2/3

• Inputs– Neurons with

processes extending to the eyes, ears, nose, tongue and skin.

• Output– Movement – arms,

legs, tongue, lips etc.

Adult Brain - Gross Anatomy3/3

• Other areas of cerebral cortex– Broca’s– Wernicke’s– Prefrontal– Temporal lobe

• Hippocampus

Adult Brain - Microanatomy1/2

• Neurons– Receiving - dendrites– Sending – axons

• Can be very long• Can be covered with a fatty

substance

• Connections between neurons– Chemical released by one

neuron– Same chemical is “sensed” by

next neuron– Chemicals may vary

depending on which neuron is sending the information.

Adult Brain - Microanatomy2/2

• Connections between neurons– Chemical released by one

neuron– Same chemical is “sensed”

by next neuron– Chemicals may vary

depending on which neuron is sending the information.

– Chemical process and result of chemical processes can be affected by subcortical activity. What??

So what. I want to know how the someone learns! 1/2

• Connections between areas are pretty much fixed

• A particular neuron may be connected to 100s of neurons in another or the same region.

How the brain learns! 2/2

• The connections of given sets of cells cause a group of cells to be active (network) and that particular network represents an idea, object, word.

• Badly formed networks or randomly active cells can lead to problems in how a particular network is recognized. e.g. inability to identify or produce sounds, syllabi or sentences.

• Previous network activation can influence which networks are subsequently activated (context).

Now I know why someone doesn’t know something but how does one

learn? • Connections between cells can be

changed and therefore new networks can be established. (weights)

• Changes are the result of repetition within a particular context.

• The larger and more distinctive the context, the easier it is to learn.

• Be wary of interference!

Developing Brain and Language

• During development gross connectivity can be affected by environment, genetics, or chemicals.

• Connections in the developing brain are the result of physical cues and activity caused by the environment.

• Fine tuning of connections can only occur after the major connections have been established. Delayed

Plasticity

• Behavioral level

• Gross Anatomy level

• Microanatomical level

• Functional Plasticity

• Continuum

Extra References

• http://www.bbsonline.org/documents/a/00/00/04/95/bbs00000495-00/bbs.pulvermueller.html

• Digital Anatomist: http://www9.biostr.washington.edu/cgi-bin/DA/imageform