Ch 11, 12, 13

Question 1

what are four variables that complicate research on laterality?

Answer 1

1. laterality is relative, not absolute
2. cerebral site is at least as important in understanding brain function as cerebral side
3. environmental and genetic factors affect laterality
4. a range of animals exhibit laterality

Question 2

laterality

Answer 2

the idea that the two cerebral hemispheres have separate functions

Question 3

planum temporale

Answer 3

Wernicke’s area

Question 4

primary auditory cortex

Answer 4

Heschl’s gyrus

Question 5

Sylvian fissure

Answer 5

lateral fissure

Question 6

double dissociation

Answer 6

two neocortical areas are functionally dissociated by two behavioural tests, performance on each test is affected by a lesion in one zone but not in the other

Question 7

commissurotomy

Answer 7

the surgical procedure of disconnecting the two hemispheres (by cutting the fibers of the corpus callosum)

Question 8

split brains

Answer 8

separated cortexes

Question 9

what are the 4 general effects of applying electrical current to the cortex of a conscious patient?

Answer 9

1. the brain has symmetrical as well as asymmetrical functions
2. the right hemisphere has perceptual functions not shared by the left hemisphere
3. stimulating the left frontal or temporal region may accelerate speech production
4. stimulation blocks function

Question 10

dichotic-listening tasks

Answer 10

two different sounds are presented simultaneously to each ear, usually the contralateral pathway is preferred

Question 11

dichaptic test

Answer 11

participants feel objects, then look at an array of objects and select those that they previously touched

Question 12

apraxia

Answer 12

severe deficits in making or copying voluntary movement sequences

Question 13

what are 3 versions of the interaction models (both hemispheres have the capacity to perform all functions but do not):

Answer 13

1. the two hemispheres function simultaneously but work on different aspects of processing
2. although the two hemispheres have the capacity to perform a given function, they inhibit or suppress each other’s activity
3. either the two hemispheres receive info preferentially and thus perform different analyses simultaneously or some mechanism enables each hemisphere to pay attention to specific types of info, thus leading to different hemispheric analyses

Question 14

preferred cognitive mode

Answer 14

refers to the use of one type of thought process in preference to another

Question 15

what are two types of lesion-related differences between male and female brains?

Answer 15

1. degree of asymmetry in the lesion effects

2. intrahemispheric organization

Question 16

superior temporal sulcus (STS)

Answer 16

a multimodal cortex, target of one of the visual streams

Question 17

dorsal visual stream

Answer 17

parietal pathway; participates in the visual guidance of movement

Question 18

ventral visual stream

Answer 18

includes both the inferior temporal pathway and the STS pathway, concerned with object perception (including colour and faces) and perceiving certain types of movements

Question 19

dynamic form

Answer 19

the shape of objects in motion

Question 20

egocentric space

Answer 20

the location of objects relative to an individual

Question 21

allocentric space

Answer 21

the location of objects relative to one another

Question 22

the argument that the dorsal stream is for online visual control of action based on 3 lines of evidence:

Answer 22

1. visual neurons in posterior parietal regions are unique in that they are active only when the brain acts on visual information
2. visual posterior parietal neurons therefore act as an interface between analysis of the visual world and motor action taken on it
3. most visual impairments associated with lesions to the parietal cortex can be characterized as visuomotor or visuospatial

Question 23

polysensory neurons

Answer 23

neurons responsive to both visual and auditory or both visual and somatosensory input

Question 24

bitemporal hemianopia

Answer 24

loss of vision of both temporal fields

Question 25

homonymous hemianopia

Answer 25

blindness of one entire visual field

Question 26

macular sparing

Answer 26

some forms of visual field loss that occur without involving the macula

Question 27

quadrantanopia

Answer 27

complete loss of vision in one-quarter of the fovea due to visual-cortex lesions

Question 28

scotomas

Answer 28

small blind spots in the visual field caused by small occipital lobe lesions

Question 29

infarct

Answer 29

dead tissue

Question 30

blindsight (cortical blindness)

Answer 30

the ability of people who are cortically blind due to lesions in their striate cortex, also known as primary visual cortex or V1, to respond to visual stimuli that they do not consciously see.

Question 31

ischemia

Answer 31

loss of (some) neurons due to sensitivity to periods of reduced blood flow

Question 32

visual agnosia

Answer 32

inability to combine individual visual impressions into complete patterns: inability to recognize objects or their pictorial representations or the inability to draw or copy them

Question 33

optic ataxia

Answer 33

a deficit in visually guided hand movement, such as reaching, that cannot be ascribed to motor, somatosensory, or visual field or acuity deficits

Question 34

prosopagnosia

Answer 34

facial-recognition deficits

Question 35

apperceptive agnosia

Answer 35

failure of object recognition in which basic visual functions (acuity, colour, motion) are preserved

Question 36

simultagnosia

Answer 36

a symptom in which patients can perceive the basic shape of an object, but they are unable to perceive more than one object at a time

Question 37

associative agnosia

Answer 37

the inability to recognize an object despite its apparent perception

Question 38

topographic disorientation

Answer 38

the inability to find one’s way around familiar environments