Lec 27 Consciousness ad creativity

Question 1

cognitive unconscious

Answer 1

a considerable amount of processing occurs without conscious

brain-lesion studies:

• blindsight
• prosopagnosia
• neglect
• amnesia (impaired at declarative memory, okay with non-declarative memory)
• split-brain patients

normal patients:
-inattentional blindness
-masked priming
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Question 2

blindsight

Answer 2

lesion study - evidence of unconscious awareness; partial blindness due to lesion in the occipital cortex; unaware of visual stimuli inside the blind field; answer above chance when forced to guess if there is anything there; answer above chance when move eyes to its location; stimuli not seen by the occipital cortex, but seen by other (intact) visually-responsive areas

Question 3

prosopagnosia

Answer 3

lesion study - evidence of unconscious awareness; have difficulty recognizing faces; showed patients familiar and unknown faces and recorded brain wave; patients answered chance at recognizing familiar faces; brain wave (P300) more intense for familiar than unfamiliar faces

Question 4

neglect

Answer 4

lesion study - evidence of unconscious awareness; damage to right parietal cortex; when showed a house on fire and a regular house patient preferred to live in regular house –> unconscious process of differences; picture-word priming: presented picture of table on the left (blocked out of conscious awareness) and bunny on the right –> chair (is this a word or nonword?) –> priming was comparable whether the related picture is on the left or right

Question 5

masked priming

Answer 5

subjects often unaware of briefly presented and masked stimuli –> guess at chance

shown fearful face for 33 msec then neutral face for 167 msec –> subjects only consciously perceive the neutral face but fear response (to the fearful face) was detected in the amygdala

Question 6

binocular rivalry

Answer 6

a pattern that arises when the input to one eye cannot be integrated with the input to the other eye; in this circumstance the person tends to be aware of only one eye’s input at a time; different images project to each eye; do not see a blend; see either one or the other, percept flips –> physical input doesn’t change, conscious percept does

Question 7

conscious perception of houses and faces

Answer 7

in binocular rivalry: face presented to left eye and house presented to right eye; when face is perceived: the fusiform face area increases activity; when house is perceived: the parahippocampal place area increases activity

multiple parts of the brain that correspond to conscious awareness
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Question 8

conscious perception of motion

Answer 8

area MT (middle temporal lobe) is activated by moving stimuli; MT is also activated when the moving stimuli are taken away, but only when people report consciously perceiving motion (motion aftereffect)

Question 9

conscious perception of auditory hallucination

Answer 9

in schizophrenic patients the primary auditory cortex is activated when hearing sounds; level of activation of primary auditory cortex rises during hallucination

Question 10

attention

Answer 10

activation in obs. 2’s (diverse brain sites for conscious perception) regions is insufficient for awareness

• neglect patients: face presented in the left visual field can induce FFA activation, but no awareness
• normals: fearful faces induce amygdala activation, but no awareness

something else is needed: attention

• attention makes info available to many other brain regions (e.g., language area)
• e.g., inattentional blindness (umbrella woman video); attentional blink

Question 11

attentional Blink

Answer 11

tying attention up impairs conscious awareness; pay attention to 2 successive targets; if target 2 falls within 200-500ms of target 1’s presentation: “blinked out” - subjects unaware of target 2; target 1 occupies attention for 200-500ms; target 2 is still processed (e.g., lead to semantic priming and N400 brain wave), but it does not reach awareness –> attention is the key