Chapter 7: The future of consciousness

Question 1

Activation of language acquisition device

Answer 1

• huge activation is not restricted to cortical regions
• speech input is directed to left hemisphere (including Broca’s area)
• earliest maturing part of brain (even in 2-month old babies)

Question 2

Language acquisition device and consciousness

Answer 2

• most language areas can be activated unconsciously during anaesthesia
• Broca’s area more activated when same sentence is repeated
• responses and activation differ between awake and asleep

Question 3

Adult vs infant consciousness

Answer 3

Tests have shown that infant consciousness is much slower compared to adult consciousness

Question 4

Masking experiment in babies

Answer 4

• masking threshold increased to 100ms instead of 60ms
• same cortical processing stages (subliminal activation then sudden nonlinear ignition)
• only supraliminal faces trigger slow negative prefrontal waves

Question 5

Conscious vision in babies

Answer 5

• assumed that babies have conscious vision but just cannot report
• fibre tracts present but not properly insulated with myelin sheaths

Question 6

Consciousness in monkeys

Answer 6

Monkeys have similar conscious phenomena to humans
- binocular rivalry, masking, subliminal perception, blindsight
- delayed response task (sustaining discharge in prefrontal and parietal regions)

Animals can be conditioned to minimally self-report using conditioned responses

Question 7

Metacognition

Answer 7

Being able to think about your own thoughts

Thought + confidence

Question 8

Consciousness in dolphins

Answer 8

After the dolphin learns to discriminate, a third option is given for a small but sure reward. This option is only chosen if the distance between stimulus and discrimination threshold is small (self-report of lack of confidence). Decision time and error rates also increase in lack of confidence

Question 9

Brodmann’s area 10

Answer 9

Located in frontopolar cortex and is disproportionally larger in humans compared to other primates.
Used for social or self-oriented reasoning

Question 10

Broca’s area

Answer 10

Located in the left interior frontal lobe and has more broadly spaced long-distance neurons compared to other areas, used to communicate thoughts with other areas

Question 11

Hominisation of prefrontal cortex

Answer 11

Densification of networks in prefrontal cortex to form complex thoughts and communicate these

Question 12

Schizophrenia

Answer 12

Neurological mental illness
Positive symptoms: hallucinations, delusions
Negative symptoms: reduction in mental capacity and organised speech

Conscious memories severely impaired, unconscious memories intact

Question 13

How to predict severity of loss of conscious perceptions in patients with schizophrenia

Answer 13

Linked to damage to long-distance fibres linking prefrontal cortex to posterior visual cortex regions
- white matter impairments selectively affect conscious access
- corpus callosum fibre impairment - resting state disruption
- dopamine D2 or glutamate NMDA receptor damage

Question 14

How do drugs like PCP or ketamine affect consciousness?

Answer 14

They both block NMDA receptors at excitatory synapses
- feedforward processes are intact but feedback is impaired
- top-down messages reduced so error signals are present and results in confusion

Question 15

What happens in patients with autoimmune diseases which target NMDA receptors

Answer 15

Acute and rapid schizophrenic symptoms develop, leading to a loss of consciousness

Question 16

How could computers simulate conscious access?

Answer 16

• flexible communication
• plasticity

Question 17

Easy and hard problems of consciousness

Answer 17

Easy problem - how does the brain function?
Hard problem - how do these processes produce subjective experiences?