Lecture 9: Brain and Behaviors
•Brain Lateralization is information that made us aware that the brain is not
bilaterally the same. The functions are not the same. The left hemisphere is more
involved in language. The right and left hemispheres don’t do the same thing.
•Discoveries were made with people who had brain damage during wars.
•Whenever they had any kind of brain damage it was different in different patients.
These results were found in adults.
•Problems in the left hemisphere (damage)
oWhenever they looked at this patients in the hospitals, when they recovered.
100% of these patients, some language (aphasia) problems. About 30% of
these patients showed some degree of recovery, and these were all left
handed people or they were ambidecerious. The least amount of recovery was
in right handed patients.
•Problems with the right hemisphere
oThere was very few language problems. That small percentage that did have
language problems, were all left handed or both handed people. Most people
showed recover from the language problem. Right handed people with right
hemisphere damage didn’t show language problem. For right handed people
it became clear that language was located on the left hand side of the brain.
In left handed people, language is bilaterally represented. Therefore, in left
handed people there is language perception in both right and left part of the
oSummary: right hand people only have language processes in on the left
hemisphere. There are isn’t much chances that there would be recovery.
However left handed people have language abilities in both hemispheres
therefore they have a chance of recovering from injury in that area.
•Language develops over time. Languages problems that are in children under the
age of five.
oDamage to either side of the brain has equal probability to inducing language
problems. Some language is found on both sides of the infant brain. 100% of
children will show recovery. There is language in children on both side of the
brain, however if there is damaged there will be 100% recovery, therefore
when one side of the brain is damaged, the other side of the brain will take
over. At this age, the language is not lateralized. Over development, language
becomes slowly lateralized.
oBrain plasticity: when you are young your brain is very plastic so that
memory development, development of new pathways. However, little kids