The Consciousness Problem

Question 1

problem of other minds

Answer 1

impossible to know how another being’s/person’s experience is like

Question 2

qualia

Answer 2

is-likeness of conscious experience (e.g., of the redness of red) , raw feeling, subjective first-person view

Question 3

explanatory gap

Answer 3

how to link subjective experience with the workings of the brain? -> hard problem of consciousness

Question 4

philosophical zombies

Answer 4

exactly like us in a physical respects and behaving just like us - but lacking conscious experience
- if philosophical zombies were possible, consciousness would be non-physical-> dualism vs. materialism

Question 5

dualism

Answer 5

consciousness is nonphysical, separate from the brain, and thus beyond the scope of the (physical) sciences

Question 6

materialism

Answer 6

consciousness is physical and can be understood by understanding the physical workings of the brain and body

Question 7

blindsight

Answer 7

blind man can “see” and avoid obstacles

Question 8

contrastive approach to consciousness (… - … = …)

Answer 8

conscious processing - unconscious processing = consciousness markers
-> holy grail of consciousness science

Question 9

states of consciousness

Answer 9

arousal (vigilance/wakefulness) are enabling conditions for conscious experience

Question 10

conscious processing

Answer 10

awake, eyes closed
seeing a face

Question 11

unconscious processing

Answer 11

dreamless sleep
failing to see a face

Question 12

consciousness markers

Answer 12

markers of states of consciousness
markers of contents of consciousness

Question 13

subcortical structures (6)

Answer 13

Cerebrum, cerebellum, thalamus, basal ganglia, spinal cord, brainstem (pons, medulla oblongata)

Question 14

cerebellum

Answer 14

does not contribute to consciousness
- complete absence of cerebellum has little effect on consciousness

Question 15

basal ganglia

Answer 15

damage can cause akinetic mutism
damage can lead to cognitive problems, but no full loss of consciousness

Question 16

akinetic mutism

Answer 16

impairments in decision making, emotion, self-initiated actions

Question 17

brainstem

Answer 17

brainstem activating systemy provide background conditions for consciousness (states)
- lesions cause coma or death
- ascending reticular activating system (ARAS) and related neuromodulatory systems
- brainstem is insufficient for contents of consciousness, but provides background conditions (states)

Question 18

coma

Answer 18

absence or arousal or consciousness

Question 19

intact brainstem and damaged cortex

Answer 19

vegetative state (presence of arousal, absence of consciousness)
- some patients with intact brainstemand damaged cortex may be misdiagnosed as being in vegetative state although they may be “minimally conscious”

Question 20

thalamus

Answer 20

may play an important role in consciousness
- lesions to the intralaminar nuclei (ILN) of the thalamus (targets of ARAS) can cause coma
- ILN and neighbouring nuclei receive little sensory input, but engage in cortico-thalamo-cortical-loops

Question 21

deep brain stimulation in anesthetised monkeys

Answer 21

can restore consciousness, restore thalamocortical connectivity, activate cortical areas, and restore cortical responses to oddball tones

Question 22

What EEG changes occur during the transition from wakefulness to sleep?

Answer 22

Back: High-amplitude slow waves appear, reflecting loss of consciousness as neurons alternate between depolarization and hyperpolarization.

Question 23

what causes slow waves during sleep or anaesthesia

Answer 23

Decreased ARAS activity
Thalamic inhibition
Cortical deafferentation (input disconnection)

Question 24

What typically happens to dreams during deep sleep?

Answer 24

Dreams are usually not reported after deep sleep.

Question 25

What are the key EEG changes in wakefulness, sleep, and altered consciousness?

Answer 25

Wakefulness: Activated EEG with fast, low-amplitude waves.
Sleep/Anesthesia: Slow waves increase, reflecting loss of consciousness.
Vegetative to Conscious State: Activated EEG increases.

Question 26

How can neural correlates of consciousness be studied?

Answer 26

Present a stimulus: Sometimes perceived (conscious), sometimes not (unconscious).
Use minimal contrast: Ensure input differences between conscious and unconscious states are minimal.
Example methods:
Bistable stimuli
Motion-induced blindness
Binocular rivalry
Continuous flash suppression
Masking
Contrastive approach: Compare neural activity for conscious vs. unconscious content.

Question 27

binocular rivalry

Answer 27

Dissimilar images shown to each eye cause alternating conscious perceptions.
Physical stimulation remains constant, but perception changes.
Neural activity reflects conscious perception, not the external world.
Helps isolate neural mechanisms for the contents of consciousness.

Question 28

fusiform face area (FFA)

Answer 28

face-specific

Question 29

parahippocampal place area (PPA)

Answer 29

house-specific

Question 30

role of primary visual cortex

Answer 30

may have n indirect role like the retina or may be crucial for consciousness
- (classic monkey binocular rivalry studies)
-> train monkeys to report their conscious percepts during binocular rivalry via lever press

–> V1 better reflects stimulus than percept
–> higher-level visual areas reflect percept

Question 31

masking and word processing

Answer 31

• Presenting masks before and/or after a
  briefly presented stimulus (e.g., a word or
  picture) can render a stimulus invisible
• By inserting blanks, the same stimulus can
  be visible
• Masking is widely used to study
  unconscious processes and contents of
  consciousness

-> unseen masked words activate high-level visual areas
-> visual words activate these areas more strongly, plus frontal and parietal areas

Question 32

global (neuronal) workspace theory

Answer 32

unconscious: feed forwarding processing
conscious: recurrent processing and frontoparietal “ignition”