Chapter 26- Associative Cortices

Question 1

which cortical layers are the most associated with associative areas ?

Answer 1

layers 2 and 3

Question 2

what are ways associative cortices are different ?

Answer 2

they receive input, often processed, from other parts of the brain

Question 3

what are the 3 different cortical laminations ?

Answer 3

1) paleocortex (oldest, small, 3 layers)
2) neocortex (newest, motor and sensory, 6 layers)
3) archicortex in the hippocampus, 4 layers, a bit more developed memory structure

Question 4

what are the 3 lobes with association cortices ?

Answer 4

frontal, parietal, temporal

Question 5

are association areas sensory or motor ?

Answer 5

they accomplish higher processing that integrates both

Question 6

what is the parietal association area responsible for ?

Answer 6

attention

Question 7

how is area 5 in parietal (association) different from premotor area ?

Answer 7

in area 5, processing info about space saw an increase in level of neuronal activity, and is always activated, always “paying attention”

however, in premotor, responds to stimuli to then do action. when there is action, activity goes up. no action- goes down. ceases when a movement will be produced

Question 8

what happens if there’s a lesion in the parietal association area ?

Answer 8

contralateral neglect - problem with identifying part of the space.

Question 9

which hemisphere is dominant for allocation of attention to space ?

Answer 9

right parietal

Question 10

what happens with a right hemisphere lesion in parietal lobe ?

Answer 10

severe left neglect (because the right hemisphere is more important)

Question 11

what happens with a left hemisphere lesion in parietal lobe ?

Answer 11

minimal right neglect (because the right hemisphere is more important)

Question 12

what happens with a partial bilateral lesion in parietal lobe ?

Answer 12

severe right neglect

Question 13

which side of the parietal lobe is activated when you’re paying attention to the left visual field ? right visual field ?

Answer 13

for left visual field- right

for right visual field- both

Question 14

how can we see that the parietal lobe is an attention specific area ?

Answer 14

if we record electrode on a monkey, it will show that when neuronal firing rate is proportional to how much we pay attention to the target, and that cells fire a lot more when we’re paying attention

Question 15

how does the parietal lobe aid the visual cortex ?

Answer 15

attention enhances neuronal response in visual cortex- a lot more spikes per second in the preferred orientation when you’re attending to the visual stimuli

Question 16

which associative area is responsible for recognition ?

Answer 16

temporal

Question 17

if we record in the temporal cortex of a monkey, when will you see a higher activation ?

Answer 17

a particular cell may react the highest to a complete view of the face in a certain angle

Question 18

what will fMRI in temporal lobe during facial recognition show ?

Answer 18

an incredible % increase in signal change when face stimulus is presented

Question 19

how are cortical columns in the temporal cortex organized ?

Answer 19

signal a particular object class or point of view, with relatively smooth transitions between object features across columns. (eg columns with facial recognition, and across columns goes from face turned left to face turned right)

Question 20

which associative area is responsible for planning forward in time ?

Answer 20

prefrontal cortex

Question 21

What is an experiment that would show that the prefrontal cortex is important in planning ? What is a clinical case?

Answer 21

1) Human subjects were presented with
a random sequence of circles, requiring a left-handed button press, and squares,
requiring a right-handed button press. Regions within lateral prefrontal cortex
were more active following events (either circles or squares) that violated repeating
patterns.

2) Phineas Gage

Question 22

How are neurons activated during a delayed response task ?

Answer 22

The neuron begins firing more rapidly wnen the screen is lowered
and remains active throughout the delay period.
(D) When the screen is lowered and raised
but no food is presented, the same neuron is
less active.

Question 23

what is a clear sign of frontal lobe trauma ?

Answer 23

not being able to sort by category