Lateralization and Language (Lecture 8)

Question 1

cerebral cortex (neo-cortex)

Answer 1

6 layers of cells, gray matter and white matter, convoluted surface increases surface area, specialized for memory, attention, perceptual awareness, thought, language, and consciousness

Question 2

sulcus (sulci)

Answer 2

grooves in cerebral cortex

Question 3

big sulci

Answer 3

fissures in cerebral cortex

Question 4

gyrus (gyri)

Answer 4

bumps in cerebral cortex

Question 5

cerebral cortex connected by:

Answer 5

the cerebral commisures (anterior commisure and corpus callosum)

Question 6

anterior commisure

Answer 6

1/10 the size of the corpus callosum

Question 7

corpus callosum

Answer 7

200 million axons

Question 8

right hemisphere is slightly _____ and ______ than the left hemisphere

Answer 8

right hemisphere is slightly larger and heavier than the left

Question 9

left hemisphere contains more:___

Answer 9

gray matter

Question 10

right hemisphere extends ______ posteriorly

Answer 10

farther

Question 11

temporal lobes display a _______

Answer 11

marked structural asymmetry

Question 12

are neurotransmitters distributed symmetrically or asymmetrically?

Answer 12

asymmetric

Question 13

Marc Dax

Answer 13

had over 40 patients with speech problems all with left hemisphere damage

Question 14

Pierre-Paul Broca

Answer 14

2 aphasic patients with left hemisphere damage “Tan”, lesions to prefrontal cortex=Broca’s area

Question 15

aphasia

Answer 15

deficient in the ability to produce or comprehend language

Question 16

Hugo-Karl Liepmann

Answer 16

apraxia almost always associated with left hemisphere damage

Question 17

apraxia

Answer 17

difficulty in performing movements when asked to

Question 18

laterality

Answer 18

the idea that the two cerebral hemispheres have separate functions

Question 19

unilateral lesions

Answer 19

traumatic brain injury, surgical removal, stroke

*unless done surgically, lesion does NOT occur within distinct boundaries of single structures

Question 20

stroke=

Answer 20

an interruption in blood supply to any part of the brain, it may lead to sufficient loss of oxygen to cause tissue death

Question 21

sodium amytal test

Answer 21

given before neurosurgery in an effort to avoid damaging areas of cortex importance for speech and language

Question 22

sodium amytal test steps

Answer 22

sodium amytal injected into carotid artery, brief (10min) inactivation of ipsilateral hemisphere, loss of function f contralateral arm and visual input from contralateral visual field

Question 23

dichotic listening test

Answer 23

based on the idea that although each ear has projections to each hemisphere auditory cortex, crossed pathways are more numerous and faster conducting

Question 24

dichotic listening test steps

Answer 24

subjects are played two different series of 3 words simultaneously (one series to each ear), then asked to recall as many of the six words as they could

Question 25

in the dichotic listening test, patients could recall more words presented to their _____ hemisphere (______ ear)

Answer 25

left hemisphere, right ear

Question 26

when the same dichotic listening test was done with melodies instead of words, patients could better recall melodies presented to their _____ hemisphere (___ ear)

Answer 26

right hemisphere, left ear

Question 27

functional brain imaging

Answer 27

subjects are asked to perform some task (e.g. read, listen to a story) while brain function is measured by fMRI or PET

Question 28

typically, _____ hemisphere more active during verbal tasks (i.e. speaking, reading, or hearing words)

Answer 28

left

Question 29

electrical stimulation

Answer 29

stimulation to either hemisphere produces twitches, dysesthesias, light flashes, buzzing sensations

Question 30

stimulation to right temporal lobe=

Answer 30

more deja vu, fear, dream state, episodic memory recall

Question 31

simulation to left frontal lobe, parietal, and temporal cortex:

Answer 31

disrupts speech

Question 32

stimulation to right temporoparietal cortex disrupts:

Answer 32

judgement of line orientation, facial expressions, short term memory for faces

Question 33

the split brain

Answer 33

ground-breaking work on the function of the corpus callosum, found through the study that the cat brain had the capacity to act as two separate brains (when corpus callosum and optic chiasm are severed)

Question 34

conclusions of the split brain experiment:

Answer 34

corpus callosum transfers learned info from one hemisphere to the other, and hemispheres can operate independently

Question 35

language is the ___ ______ of all cognitive abilities

Answer 35

most lateralized

Question 36

right hemisphere is capable of understanding

Answer 36

simple spoken and written words and sentences

Question 37

tachistoscope

Answer 37

visual information presented to each visual field while patient stares at center “fixation cross”

Question 38

most subjects accurately identify objects explored with their ____ hand. (most braille readers read more rapidly with their ____ hand)

Answer 38

left hand

Question 39

left hemisphere damage=

Answer 39

apraxia

Question 40

more activation in ___ hemisphere versus ____ hemisphere during ipsilateral hand movement

Answer 40

more activation in left versus right

Question 41

right hemisphere is better at:

Answer 41

spatial tasks like putting together puzzles with blocks

Question 42

emotion = _________ hemisphere

Answer 42

right (emotional content of readings’, expression of emotions, identifying facial expressions

Question 43

subjects that felt 3D objects with _____ hand were more accurate in identifying 2D test stimulus that best represented what they felt if it were made of cardboard and unfolded

Answer 43

left

Question 44

Broca’s area=

Answer 44

left inferior frontal

Question 45

Wernicke’s area=

Answer 45

left planum temporale

Question 46

large anterior lesions most likely to produce:

Answer 46

expressive symptoms

Question 47

large posterior lesions most likely to produce:

Answer 47

receptive symptoms

Question 48

3 evolutionary theories on why we have cerebral asymmetry of function:

Answer 48

analytic-synthetic theory
motor theory
linguistic theory

Question 49

analytic-synthetic theory

Answer 49

two modes of thinking (analytic (left) and synthetic (right), vague and essentially untestable

Question 50

motor theory

Answer 50

left controls fine movements-speech is just a category of fine movement, left damage may produce speech and motor deficits

Question 51

linguistic theory

Answer 51

left hemisphere is specialized for language, deaf people with left hemisphere damage show deficits when signing but not mimicking

Question 52

commissurotomy limits:

Answer 52

convulsive activity (may never have another major convulsion)

Question 53

when you present a picture (ring) to the right visual field (left hemisphere) of a split brain patient:

Answer 53

left hemisphere can talk and say ring

right hand can show you, left hand can’t

Question 54

when you present a picture (key) to the left visual field (right hemisphere) of a split brain patient:

Answer 54

right hemisphere can’t talk and subject will report that they do not know what it was
left hand can show you what it was, right hand can’t

Question 55

helping- hand phenomenon

Answer 55

presented with two different visual stimuli, the hand that “knows” may correct the other

Question 56

chimeric figures task

Answer 56

only symmetrical version of right half of faces recognized (indicates competition between hemispheres)

Question 57

chimeric figures test and completion

Answer 57

the left hemisphere of a split-brain patient sees a single normal face that is a completed version of the half face on the right. at the same time, the right hemisphere sees a single normal face on the left