cognition

Question 1

lateralization

Answer 1

division of labor between the 2 hemispheres – certain functions are more processed in one brain than the other
- Exchange of info through a set of axons: corpus callosum & anterior commissure/ hippocampal commissure/ other small comm.

Question 2

L hemi

Answer 2

dominant for speech production (for 95% of right handers; 80% of left handers– more variable)

Question 3

R hemi

Answer 3

dominant for understanding meaning of sentences & more

• More adept than the L at comprehending spatial relationships
• More responsive to emotional stimuli than L

Question 4

testing for functional dominance in hemispheres

Answer 4

• observe patients with stroke /traumatic injury in left brain
• fMRI: more blood flow / activity in left hemi during speech tasks

Question 5

Contralateral connection b/w hemi & body

Answer 5

each hemi is connected to the contralateral skin receptors & muscles

• Left hemi: only see right half of world
• Right hemi: only see left half of world
• Each hemi gets auditory info from both ears but slightly stronger info from the contralateral ear

Question 6

• Exception to Contralateral connection b/w hemi & body

Answer 6

• both hemis control trunk muscles & facial muscles

* taste & smell : uncrossed (gets info from both sides of tongue; nostril on its own side)

Question 7

path of light to each hemi

Answer 7

• Light from right half of visual field  strikes left half of each retina  connects to left hemi
• Left visual field  right half of each retina  right hemi
• A small vertical strip down the center of each retina connects to both hemis
- Half of axons from each eye cross at optic chiasm

Question 8

Split brain operation

Answer 8

• Focus: origin of seizures  may have multiple / important region
• Cut corpus callosum to prevent epileptic seizures from crossing to the other hemi
  • Less frequent seizures & only one side of body
  • Epileptic activity cannot bounce back and forth across corpus callosum: seizure may not develop

Question 9

humans vs birds/other species in visual connection

Answer 9

birds: left eye connected to right hemi
humans: left eye connected to both (left retina to left hemi)

Question 10

epilepsy

Answer 10

repeated episodes of excessive synchronized neural activity

can result from mutation in GABA receptor gene (loss of inhibition), brain tumour

Question 11

split brain patients

Answer 11

• Maintain intellect & motivation
• Walk & talk normal
• Use hands together on familiar tasks i.e. tying shoes
• Struggle: use hands together on new tasks i.e. piano
• Can use hands independently (U + C)

Question 12

Roger sperry’s experiment

Answer 12

revealed subtle behavioural differences for split brain people
Split-brain patients can:
- Point with L hand to what right hemi saw (left visual field)
- Point with R hand to what left hemi saw (right visual field)
- Say what left hemi saw
- CANNOT say what right hemi saw (L hemi has no access)
- “hat | band”: say band ; can point to hat with left hand
- More time – may be able to say when stim presented to left visual field (smaller commissures)

Question 13

Right hemisphere -more adept than the L at

Answer 13

comprehending spatial relationships i.e. wayfinding even in familiar areas
• Ppl with R hemi dominance for speech have L hemi dominance for spatial relationships
- More responsive to emotional stimuli than L
• i.e. emotions in gestures/voice tone  damaged R: can’t understand humor & sarcasm
- deciding T/F – ppl with intact L hemi : rely on analysis by L hemi vs damaged L hemi: rely on intuitive reactions to emotional expressions by R hemi
- inactive R hemi: do not experience strong emotions nor remember feeling them

• most tasks (esp. difficult ones) require cooperation by both hemis

Question 14

underdevelopment of lateralization – corpus callosum doesn’t completely develop in some people

Answer 14

compensatory hypertrophy (growth): anterior & hippocampal commissure
better performance on some tasks compared to split brain people
stroke/ concussion : adjacent areas can compensate for damaged area (no neural growth)

Question 15

productivity

Answer 15

human language: productivity – able to improvise new combinations of signals to represent new ideas

Question 16

Chimpanzees learning to communicate

Answer 16

ASL, press keys bearing symbols to type messages on computer
 symbols seldom used in new original combinations (lack productivity)
 mainly to request , seldom describe
 showed min. moderate understanding

Question 17

bonobos learning to communicate

Answer 17

• offspring of a bonobo which researchers tried to teach language to developed language comprehension comparable to a 2yo child
  • understand> produce
  • use symbols to describe objects (not requesting them) & past events
  • frequent original requests

Question 18

describe study on white crown sparrows’ song production

Answer 18

only males sing – only 1 song produced
isolation experiment: collected eggs from nests, raised male WCSP in soundproof chambers in lab
songs produced barely resemble normal WCSP songs at 150 days – important role of experience
if chicks tutored with conspecific songs on tape (regardless of dialect): 150 day old WCSPs were able to sing a good copy of the song
– Not with heterospecific songs
- songbirds have circuits that control learning & production of songs – production: HVC – RA – brainstem – control muscles of syrinx (vocal organ); learning: auditory info is sent to anterior forebrain – connected to the circuit

Question 19

Williams syndrome

Answer 19

poor at tasks, poor planning & inhibition, frequent lapses of attention (impaired intelligence) BUT speak grammatically & fluently

– - language requires more than developed brain & overall intelligence

Question 20

FOXP2 gene’s role in language acquisition

Answer 20

regulates a protein that promotes synapse info in cortex & BG
• In humans & chimps: differs in two places
 affects brain development, jaw & throat structures (speech)
 humans: more connections from motor cortex (vocal cords) to rest of cortex  complex speech production

Question 21

sensitive period for language learning

Answer 21

• Adapted to learn language best during a sensitive period (early in life)
• Adults> Children: memorize vocab of second language
• Children> adults master grammar & pronunciation
• ppl who learn 2nd language after age 6: activate just the left hemi for both languages vs before 6: bilateral activation & stronger connections b/w hemispheres
• children who began ASL while young > started later
• a deaf child who learns sign language early can learn a spoken language later (poor pronunciation)
• child who learns no language while young: permanently impaired at learning any kind of language (or delayed exposure to language: lasting deficits)

Question 22

Broca’s aphasia

Answer 22

• all forms of language communication impaired (speaking, writing, gesturing, using sign language)
• Broca’s area helps to organize speech not produce it
• speech: meaning but sparse
  • omit pronouns, prepositions, etc
  • trouble is with word meanings not just pronunciation
  • or: leave out weakest elements like tense

comprehension

• understand most speech except when meaning depends on prepositions / word endings/ complex grammar
• knowledge of grammar not entirely lost
• resemble distracted person – rely on logical guesses more

Question 23

broca’s area

Answer 23

part of the frontal lobe of left cerebral cortex near motor cortex

Question 24

Wernicke’s area

Answer 24

area of the brain located near the auditory part of left cerebral cortex

Question 25

Wernicke’s aphasia

Answer 25

(fluent aphasia) - could read & write but poor language comprehension * impaired ability to remember names of objects * can speak smoothly - symptoms and damage vary (like Broca’s) damage extends into thalamus & BG 1. articulate speech (fluent, no problem with pp, conjunctions / grammar) 2. difficulty finding the right word (anomia: hard to recall names of objects  make up & substitute names, roundabout expressions ) 3. poor language comprehension (speech, writing, sign language)