Study Guides (390,000)
CA (150,000)
UTSC (10,000)
Psychology (2,000)
PSYB65H3 (100)

Brain Lat.


Department
Psychology
Course Code
PSYB65H3
Professor
Ted Petit

Page:
of 3
Brain Lateralization: Chapter 4 Lecture 9
-refers to the fact that brain function does not happen bilaterally, different structures serve
different purposes
Historical Perspectives:
- began in testing of WII brain injuries, each patient exhibited different speech
impairments
Brain damage observed in left hemisphere:
-100% showed some form of aphasia (problems in language)
-30% showed some recovery in varying degrees, it was found that most left/ambidextrous
peopled recovered
-the least amount of recovery was reported in right handed people
Brain damage observed in right hemisphere:
-very few language problems and rarely lead to language problems
-those who did show aphasia were left/ambidextrous
-it was concluded that because right hemisphere damage did not result in language
problems and right handed people also did not show symptoms, language is attributed to
left hemisphere functioning
-in left handed people, language is bilateral, both hemispheres deal with language
-If damage is done to the RH and you are RIGHT handed then NO aphasia
-but if damage is done to LH and you are RIGHT handed then aphasia
-if LEFT handed, damage in either LH or RH can effect language but the other H not
damage can compensate
Children (below age 5) and Brain Damage
-at this age language is still bilateral. Therefore any damage to either lobe can effect
language.
-100% of patient s will show recovery, this is because the other NOT damaged H will
compensate
-at this age the brain is very plastic and some will have damage H removed (because
scarred tissue can result in seizure late on in life)
-during development brain becomes lateralized
Acolosual patients (born without corpus collusom)
-those with no CC have language on both side
-therefore it seems that during development in ‘normal’ person both H are capable of
language acquisition but LH seems to suppress RH and become dominant and more
www.notesolution.com
competent
LH differences:
- plantum temperale: area of primary language. When taken out it was shown to be more
heavy and convoluted and larger by 1/3.
-therefore the autonomy might be better equipped to handle language
-this automical difference can even be see in birds and results in there vocalisation
-also noted in 10-31 weeks of gestation
Sodium Amytal Test
-used in patients who qualify for hippocampus removal(to much scar tissue from damage
and therefore increase chance of siezures , this is only done in sever cases when
barbiturates are not working and are debilitating
-used to identify what part of the brain is effected because you cannot just cut into
temperal lobe (critical for language)
-injected into one side R-side will put to sleep RH: l lay down, arms out, and count
backwards
-if right hand drops: LH if left hand drops : bilateral
Test in Colllage kids
- revealled that right handed kids, where info is presented(verbal) to the LH it is
processed faster than non verbal hemp.
-this suggest that when presented to the RH it attempts to decode it and when unable to
will give to LH to process
Split Brain Patients
- used to stop seizures from spreading to other side of the brain ie) Jasonian marche can
create a grand Mall seizure (recall JM refers to seizure that begins in a specific locale
then begins to spread and cross over to other H)
-CC is cut (note: it is not the only neurofiburlary connection between H
-are normal in every day life
Research of Gazzaniga & Sperry:
-used students and presented an image to one H or the other
-they would present either a verbal image (word) or a pictoral image (non verbal)
-precede to ask student what the A. saw (verbal response) or B. pick out what they saw by
feeling object (motor response)
INFO PRESENTED TO RH in RIGHT HANDED
A. presenting object visually (non verbal) to non-verbal hemp. (RH)
www.notesolution.com
i. When asked what it was were unable to verbally respond/describe it
-language is in LH; received in LH and respond through LH
Ii. Tell them to feel and pick out object with right hand they are unable
-Right hand is communicating with LH and LH did not see anything
Iii. Tell them to feel and pick out object with Left hand the can show you
-Left hand is communicating with RH (who did see it)
B. presenting a word visually
i. cannot verbally tell you what they say
-word presented to non verbal hemp (RH)
Ii. Asked to pick out obeject with right hand
-unable to because right hand communicates with LH who did not see it
Iii. Cannot pick out verbal info in non-speaking hemp. Except for small words that were
learned early in life, suggesting that the RH might have language from when development
still held it bilaterally)
RIGHT HEMP abilities:
1. Musical abilities: -music presented to left ear (RH) will be more remembered
- damage in RH=problems with music abilities
2. Geographical and Spatial abiliites
www.notesolution.com