chapter 4 Cerebral Specialization and Aging

Question 1

what is Lateralization

Answer 1

refers to functions assifned to one hemisphere or the other

Question 2

what are the functions of lateralization

Answer 2

localization- specific functions in different lobes of each hemisphere
-Dominance-a hemisphere having dominance for certain functions (priority)

Question 3

comparison of the left to right hemisphere

Answer 3

the left

• weighs more
• longer in adults
• lateral fissure is longer and better defined
• temporal pole is more distinguished
• parietal operculum is larger and deeper
• ventricle is larger
• visual cortex vells are larger
• pyramidal tract is larger/thicker

Question 4

common functions of both hemispheres (equal)

Answer 4

• Olfaction
• Vision (17, primary visual cortex; 18/19, visual association areas)
• Audition (41, primary audiroty cortex; 42/37 and 22, auditory association areas)
• Somesthesia(3/1/2 primary sensory cortex; 5/7 sensory association areas)
• Stereogenesis/ability to name via touch(5/7)
• Voluntary motor movement (4 primary motor cortex-gross motor movement)
• Executive functions (prefrontal cortex, 38% of brain is in the frontal cortex)
• 96% of descending fibers decussate at brain stem, resulting in contralateral innervations

Question 5

special functions of the right hemisphere

Answer 5

-spatial itegration/discrimination (disorder= visual agnosia)
-nonverbal ideation (creativity;disorder affects artistic skills)
-facial discrimination (disorder is propagnosia-can recognize by voice not face)
-tonal discrimination (disorder is dysmusia)
metalinguistic ability (disorder -maks like faces-affects humor, body language, and cues difficulty interpretting others faces)
-language comprehension/ production (only 2-5% have right language center- very little language on right side of the brain)

Question 6

special functions of the left hemisphere

Answer 6

• eye/ hand coordination, especially for writing with the right hand(exners area 8/9)
• language comprehension (disorder-wernickes aphasia, area 22)
• language production (disorder- Broca’s aphasia, area 44/45)
• speech programming (disorder-apraxia of speech, area 44/45)
• wernicke’s area connects to broca’s area via arcuate fasciculus (damage - conduction aphasia)
• angular gyrus(39) and supramarginal gyrus (40) damage-learning disability
• word recall disorder-anomia
• writing disorder- dysgraphia
• reading disorder-dyslexia
• math disorder- dyscalculia

Question 7

evidence for left hemisphere dominance

Answer 7

• even the vast majority of left handers have left hemisphere dominance for language
• 92% of fetuses tend to use right thumb when sucking supporting genetic predisposition
• most perple are right ear, hand, arm,leg dominant.

Question 8

gender differences

Answer 8

• males tend to have more white matter and csf -than females( move faster, have a faster impulse sending)
• males tend to have larger parietal lobes and a larger amygdala
• males appear better at spatial tasks
• serotonin levels are 52% higher im men-makes them calm
• females tend to have more gray matter, larger frontal cortex and limbic lobe-smarter more decision making and more emotional
• females and homosexual men tend to have smaller hypothalamic cells
• females appear better at verbal tasks
• emotional memories stimulate the right amygdala in men and the left in women.

Question 9

ARC- after the age of 30

Answer 9

brain mass shrinks by .25%

Question 10

ARC- by age 80

Answer 10

7% of brain mass has been lost

Question 11

ARC-neocortex (outer 1/2-1 inch of the brain)

Answer 11

• does not fully function till 3-4 years of age

- results in poor memories prior to this

Question 12

ARC- cell loss

Answer 12

• occurs with age

- primarily in frontal, temporal, and occipital lobes

Question 13

ARC-telomeres (tips of chromosomes)

Answer 13

help with cell repair- up to a certai npoint

Question 14

ARC- arterial plaque, neuritic plaque, and neurofibrillary tangles

Answer 14

increase with age, and the last two are seen in parkinson patients

Question 15

ARC-alcohol

Answer 15

apears to damage younger brains more than older brains, affects the frontal cortex and the hippocampus

Question 16

ARC-male brains shrink…

Answer 16

faster than female brains

Question 17

ARC-most neurotransmitters

Answer 17

decrease with age, toxic materials tend to accumiulate with age (mercury)

Question 18

ARC-mutations

Answer 18

also tend to increase with age (mitochondria get deformed)

Question 19

ARC- Myelin

Answer 19

tends to degenerate starting around age 60 (things become slower)

Question 20

ARC- Blood flow

Answer 20

tends to decrease with age; blood pressure may increase (over 50)

Question 21

ARC-sensory input

Answer 21

begins to diminish (hearing, vision)

Question 22

ARC-word retrieval/memory problems

Answer 22

slowly increase with age

Question 23

ARC-motor coordination

Answer 23

tends to diminish with age

Question 24

ARC- Neurogenesis

Answer 24

appears to help the brain (hippocampus), as well as active use of brain

Question 25

ARC- Exercise

Answer 25

is beneficial to the brain

Question 26

ARC-speed of processing

Answer 26

tends to be a matter of insufficient storing, (incomplete storage of details) rather than in retrieving that information