Chapter 4 - Hemispheric Localization & Lateralization

Question 1

Laterality

Answer 1

• superior function of one part of the body
• rather than symmetrical across both side, one side functions better than the other

Question 2

What are some examples of lateralization of function in other species?

Answer 2

• songbirds
• domestic chickens
• rats and cats
• primates

Question 3

What are some examples of physical or neuroanatomical asymmetry in humans?

Answer 3

• faces
• R hemi. larger than L
• R frontal lober larger than L

Question 4

Language

Answer 4

• L hemi dominant
• R hemi plays a role in appreciation of irony and metaphors
• PET scan studies proved this

Question 5

Visuospatial ability

Answer 5

• R hemi dominant
• mental rotation
• perception and recognition of faces (fusiform face area)
• direction and distance

Question 6

Imagery

Answer 6

• depending on imagery, either hemi

Question 7

Men are more skilled at?

Answer 7

• better spatial abilities
• more skilled at mental rotation of objs and spatial navigation

Question 7

Attention

Answer 7

• Focal and divided attention = L hemi
• Global and sustained = R hemi

Question 7

Mathematical ability

Answer 7

• writing and reading numbers = L hemi
• calculations and mental math = R hemi

Question 7

Perception of music

Answer 7

• Melody = R hemi
• Lyrics = L hemi

Question 8

Women are more skilled at?

Answer 8

• better language abilities
• superior on verbal fluency, verbal memory, and object location

Question 9

Handedness

Answer 9

• degree to which an individual preferentially uses one hand
• 96% R handed people are L hemi dominant for language
• 70% L handed people are L hemi dominant for language, the other 30% use both hemis for language which causes deficiency in visuospatial tasks

Question 10

Commissurotomy

Answer 10

• surgical procedure that severs the corpus callosum so seizures do not spread to other regions
• causes disconnection syndrome

Question 11

Disconnection Syndrome

Answer 11

• two hemispheres can no longer communicate, act independently
• split brains - sensory information is only sent into one hemi, joe from video an EX

Question 12

Objects shown in the left visual field are projected into the ____ hemi, which controls the ____ side of the body.

Answer 12

• Right
• Left

Question 13

Objects shown in the right visual field are projected into the _____ hemi, which controls the _____ side of the body.

Answer 13

• Left
• Right

Question 14

What are some characteristics of split-brain patients?

Answer 14

• somatosensory effects - impaired IQ, mute, trouble following commands
• visual effects - blindness in one eye
• la main etrangere (the stranger hand) - L hand opposes the R
  
  • EX: R hand buttons a shirt, L hand unbuttons it; R hand picks out a pair of socks, L hand picks out a diff pair

Question 15

Do left-handers die sooner than right-handers?

Answer 15

• some studies have indicated that they do - BUT some might’ve switched to R handedness, and some might’ve been related to accidents due to most tools being made for R handed people

Question 16

Split brain example

Answer 16

• if a picture of a cat is shown on the R visual field, it will go to the L hemi, pt can SAY cat
• if a picture is shown on the L visual field, it will go to the R hemi, pt cannot say cat, but can DRAW one