Class Notes (838,404)
Canada (510,881)
Psychology (3,528)
PSY100H1 (1,637)
Lecture

B65 Lec 9 Laterality.docx

3 Pages
59 Views
Unlock Document

Department
Psychology
Course
PSY100H1
Professor
Michael Inzlicht
Semester
Winter

Description
B65 LECTURE # 9: Laterality (Localization and Specialization) Historical/General Overview • First laterality obvs came from war (the injuries that soldiers experienced, ex. Bullet wound on the left or right side) • LEFT hemi wound for adults: o 100% show some aphasic (lang problems) symptoms o Approx 30% show recovery, these people were mostly left-handed or ambidextrous o The least amount of recovery was in right-handed individuals (because language is predominantly in left brain when you’re right-handed). o Right hemi is also capable of lang in left-handed individuals meaning not all fxn is lost if left hemi is wounded o Theorized that ambidextrous are actually just lefties who are forced to learn right  We can test ambidextrous by getting someone to look through a telescope (which eye), throw a ball, get them to check if a clock is ticking (which ear) • RIGHT hemi wound for adults: o Most showed a few and minor aphasic symptoms, but rarely full-blown aphasia o Those that DID show aphasic problems were always the lefties/ambidextrous but they show very good recovery o Thus, lefties clearly have language on both sides so wounds on left or right will affect them but it will always only be mild o but righties have more severe issues for left hemi, but nearly no issues for right hemi • either hemi damage for kids (less than 5 y.o) has an equal probability of affecting lang o thus we conclude that lang is on both sides at that point, unlike an adult o 100% of kids who suffer brain damage show recovery o Therefore, kids are kind of like lefties o Child’s brain is not yet fully lateralized o Over time, brain becomes more and more lateralized (beginning at 5 y.o  teen years) o Lateralization primarily occurs in right-handed individuals, but lefties have more split on both sides o Child can even recover from an entire side of the brain being removed because they still have so much plasticity and lack of lateralization Acollosal People: • Born without a corpus callosum • Towns in Quebec with a fairly high percentage of people who genetically have this • They have language on both sides of brain (even in right-handed adults) • We conclude that left hemi is better at lang and so it will actively suppress right side • But if there is no corpus callosum to let the hemis communicate, the left hemi won’t do this! Children w/ early extensive brain damage: • Language is almost always on opposite side of brain as the damage -it’s actually been suggested that lefties may have had some small amount of brain damage when they were younger and that’s why their brain never lateralized Anatomy of Left Brain: • Left temporal lobe, mainly the planum temporale, is the primary language area • in left brain, planum temporale is heavier by 1/3 and more convoluted than same structure on the right • left-specialization is found to be a very genetic, primitive thing that has been around for ages • other species present the same left-specialization • therefore, it’s not just a lifetime of use that causes left brain to be specialized for language. Left is just inherently more capable to begin with. • Between 10 to 20 week of gestation, we already show left temporal being larg
More Less

Related notes for PSY100H1

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit