Chapter 5: Theorising consciousness

Question 1

Homunculus fallacy

Answer 1

If consciousness is a stage with a homunculus as the actor and an audience present, do the audience members also have a homunculus (iteratively)

Question 1

Global workspace

Answer 1

Internal system used to store mental images across different specialised processes

Question 2

Solutions to homunculus fallacy

Answer 2

Dennett - replace audience’s intelligence with explicit algorithms
Baars - replace audience with other unconscious processors

Question 3

What is consciousness according to William James?

Answer 3

Consciousness is an organ developed specifically to direct a nervous system too complex to self-regulate

Question 4

Which regions of the brain are not as well connected?

Answer 4

Sensory areas tend to only be connected to other related areas

Question 5

Which region of the brain is more developed for connections with other regions?

Answer 5

The prefrontal cortex connects to all major hubs reciprocally, usually with interconnections as well

Question 6

Role of the thalamus

Answer 6

Attention, vigilance, synchronisation

Question 7

Role of the basal ganglia

Answer 7

Decision making and motor control

Question 8

Role of the hippocampus

Answer 8

Episodic memory and recollection

Question 9

Why is one of the signatures of consciousness an increase in activity in the prefrontal and parietal lobes?

Answer 9

These areas have the most long-distance connections to other regions
- more common and prominent in humans
- dendrites are larger and more numerous at the front of the brain compared to the back

Question 10

FoxP2 gene

Answer 10

This gene has two mutations specific to humans relevant for modulation of language networks

Question 11

How does facial recognition work?

Answer 11

1. short connections clean incoming image from retinas
2. compressed image sent to thalamus then V1 in occipital lobe
3. image transmitted to face clusters in right fusiform gyrus
4. image transmitted to necessary part of cortex

Question 12

How can there be so many possible differentiated conscious states from a limited number of assemblies?

Answer 12

Each state is made up of a combination of independently activated local assemblies

Question 13

Selfridge’s pandemonium model

Answer 13

The brain is a hierarchy of daemons specialised for tasks and each one competes for their own interpretation to be the main one.

Question 14

What is one limitation of Selfridge’s pandemonium model

Answer 14

It assumes and organises for a strict feedforward hierarchy - in reality, neural systems have several recurrent loops and bidirectional projections

Question 15

Attractor state

Answer 15

Group of neurons that form reproducible and long-lasting patterns of activity which progressively come to concordant agreement

Question 16

Convergence zones

Answer 16

Send and receive projections to and from distant brain regions to allow integration
- mainly in prefrontal cortex, anterior temporal lobe, inferior parietal lobe and precuneus

Question 17

Why are inactive neurons still useful?

Answer 17

• says its interpretation is not present or relevant to current context
• perception only possible through silencing of irrelevant neurons
• P3 wave occurs from inhibitions’ positive potentials
• slow negative waves from activation of parallel neurons

Question 18

Simultaneity of activations in peripheral vs higher-order levels

Answer 18

Peripheral levels had simultaneous activations of light and sound neurons

Higher-order levels could only have one single integrated state of firing

Question 19

Endogenous global activation

Answer 19

Can occur in the absence of a stimulus from higher-order areas to sensory areas. This activation can block and prevent attention
- inattentional blink