Quiz 2

Question 1

What percentage of right and left handed people have language localized in the left hemisphere?

Answer 1

Right handed people it’s 90-95% Broca’s and Wernicke’s area are in the left hemisphere for 95% of right handers.
Rasmussen + Miener: In left handers, language is represented in the left hemisphere 70%, in the right hemisphere 15%, and bilaterally 15%.

Question 2

Explain the differential roles of the right and left hemispheres related to language (assuming individual is right handed)

Answer 2

LEFT: superior in understanding morphology (meaning cues) and phonology (sound clues). Superior performance in search for words using different cues, and involved in sentence implication (integrating semantic and syntactic info)
RIGHT: superior in understanding logography (picture cues). Superior performance in task involving learning associations between nonsense words and symbols.
(p337)

Question 3

Based on Kolb’s discussion of Specialization Models, what are the lower level processing functions that appear to be related to the right and left hemisphere?

Answer 3

LEFT: operates more analytical, logical, computer-like fashion analyzing stimuli input sequentially and abstracting relevant details to which it attaches verbal labels
RIGHT: synthesizer, more concerned with overall stimulus configuration. Organizes and processing information as a whole.
(p299)

Question 4

Based on studies of deaf individuals who have or have not acquired signing, what are the implications for language lateralization?

Answer 4

If experience with auditory language is absent, lateralization of some aspects of non auditory language function are abolished. This suggests that…
1. the absence of language experience somehow abolishes certain aspects of cerebral asymmetry
2. the expression of cerebral asymmetry depends on language experience
(p334)

Question 5

Approximately what percentage of the cortex in monkeys is associated with visual processing?

Answer 5

Total surface area of vision related regions is ~55% of whole cortical surface.
(anyone else find anything that more directly addresses this question? email me)

Question 6

Scotoma

Answer 6

Small blindspot in visual field caused by small lesions, an epileptic focus, or migraines of the occipital lobe

Question 7

Apperceptive Agnosia

Answer 7

Inability to develop a perception of the structure of an object.
Elementary sensory functions appear to be in tact but a perceptual deficit that prevents recognition of an object is present.

Question 8

Associative Agnosia

Answer 8

Object-identification deficit associated with stored information about objects (i.e.: memory)… in context of preserved ability to copy or match stimuli presented in affected modality (e.g.: can copy a drawing but cannot identify it)

Question 9

Alexia

Answer 9

Inability to read. Damage to left fusiform and lingual areas. A form of object agnosia- inability to construct perceptual wholes.

Question 10

Optic Ataxia

Answer 10

Deficit in the visual control of reaching and other movements and in eye movements.

Question 11

Prosopagnosia

Answer 11

Facial recognition deficit: cannot recognize faces, but can use info from faces (e.g.: birthmark) to identify faces. Can also understand information from faces (e.g.: lip reading, imitating facial movements and expressions)
Right parietal lesion.

Question 12

V1

Answer 12

Primary visual area (the striate cortex) that is responsible for Color, Form, and Motion. Receives the largest input from the lateral geniculate nucleus of the thalamus and projects to all other occipital regions. First processing level.
STRIATE: (thin stripes- color perception; thick stripes- form perception; pale stripes- motion perception).
Damage to this area causes blindsight

Question 13

V3

Answer 13

Form perception and perhaps global motion

Question 14

V5/MT

Answer 14

Motion; lesions produce inability to perceive objects in motion. Objects at rest are perceived, but when the object begins to move, they vanish.