lecture 28: how does the brain think

Question 1

the nature of thought

Answer 1

psychological constructs:
- idea that some mental ability exists as an entity
- thought, attention, emotion and motivation
diffficult to localize constructs in brain

Question 2

language in humans

Answer 2

gives humans an edge, a way to categorize info and organize time
- syntax or rules unique to humans

Question 3

sequencing events in time

Answer 3

language might be byproduct of brain organized to string together events ex. motor movements for hunting

Question 4

frontal lobes role

Answer 4

new movement and thought sequencing

• organize both behavior and thinking
• damge can cause difficulty generating novel solutions to problems

Question 5

neural unit of thought

Answer 5

cell assembly: set of neurons that become functionally connected via common sensory inputs

• organized into systems and subsets
• basis of perception, memory and thought (Hebb)

Question 6

newsome and colleagues

Answer 6

trained monkeys in apparent motion paradigm and made single cell recordings
- found that perception of apparent motion was influecned by individual neurons

Question 7

consensus

Answer 7

cell assembly represents sensory event that activity of individual neurons detect
- assemblies converge inputs from individual neurons to arrive at consensus

Question 8

basis for cognition

Answer 8

cell assemblies come together like words in language to produce coherent thoughts
- combination of individual neurons into novel neural networks produce complex mental representations

Question 9

association cortex

Answer 9

neocortex outside the primary sensory and motor corticies produce cognition
- receives info that is more highly processed than information in primary corticies

Question 10

3 parts of association cortex

Answer 10

temporal: related to visual and auditory
parietaL: somatosensation and movement guidance
frontal: parietal/temporal association and subcortical regions

Question 11

ventral visual stream

Answer 11

knowledge about what objects are is in temporal association cortex

Question 12

dorsal stream

Answer 12

knowledge of how to grasp the object

Question 13

visual agnosia

Answer 13

temporal association cortex is destroyed

- lose visual knowledge about objects (what they are and what they are used for)

Question 14

2 types of visual agnosia

Answer 14

apperceptive: unable to perceive an object in its entirety
associative: able to perceive, but cant recognize and cant connect it to semantic representations in memory

Question 15

spatial cognition

Answer 15

range of mental functions related to transversing space or manipulating objects in space
- test using 3D object rotation

Question 16

navigation

Answer 16

moving body from point A to B

• creation of mental map in hippocampus (allocentric)
• memorizing sequences of landmarks in basal ganglia and parietal cortex (egocentric)

Question 17

deficits in spatial cognition

Answer 17

damage to parietal association regions causes deficits in processing complex spatial information
- right posterior parietal cortex
ex. topographical disorientation
damage to hippocampus and surrounding areas of MTL cause deficits in cognitive mapping

Question 18

topographical disorientation

Answer 18

difficulty perceiving relative locations of objects with respect to the self
- right posterior parietal lobe
inability to set a course between current location and nearby targets

Question 19

attention

Answer 19

selective narrowing/focusing of awareness to part of sensory environment or class of stimuli
- inward or outward
Moran and desimone show V4 neuorns can be trained to respond selectively to info in receptive field

Question 20

selective attention (moran and desimone)

Answer 20

trained animal to attent to stimuli in one area of visual field and ignore other areas
rewarded vs unrewarded locations to train
neurons only fire when correct stimulus was present in correct location
conclusion: same stimulus can activate a neuron at one time but not another depending on learned focus of attention property of single neurons

Question 21

deficits of attention

Answer 21

frontal: overly focused on environmental stimuli and cannot direct attention to an excessive degree or shift attention
parietal: contralateral neglect
- right hemisphere damage

Question 22

extinction (contralateral neglect)

Answer 22

neglect of information on one side of body when presented simultaneoulsy with information from other side of the body
- exhibit as they recover