Consciousness and arousal 1

Question 1

What is dualism, monism and epiphenomalism?

3 marks

Answer 1

• Monism
  
  • mind and matter same thing
• Dualism:
  
  • Mind and body are seperate
• Epiphenomalism:
  
  • mental phenomena caused by physical processes in the brain

Question 2

Define the ‘neural correlate of consciousness’.

2 marks

Answer 2

Smallest set of brain mechanisms and events sufficient for specific conscious feeling

Question 3

What is the hard problem of consciousness?

1 mark

Answer 3

That its a subjective experience - how can we know we are seeing the same thing

Question 4

What are the 2 levels of consciousness?
2 marks

Answer 4

• Arousal/state of consciousness - can be measured behaviourally by signal amplitude that triggers criterion reaction
• Content of consciousnes and conscious states

Question 5

What are the different states of consciousness?

3 marks

Answer 5

• Persistent vegetative state
• Comatose state
• Minimally conscious state

Question 6

What is major consciousness loss usually a result of?

1 mark

Answer 6

Brain damage - certain amount of processing occurs on sensory side

Question 7

What do hemispheric lesions to V1 result in?
2 marks

Answer 7

• Patient may be blind on one side but due to central processing may be able to visualize moving gratings
• Shows that the processes go on in the brain that may influence behaviour

Question 8

What is ‘blindsight’?

1 mark

Answer 8

Sufferer responds to visual stimuli without actually perceiving it themselves

Question 9

What does multivariate pattern analysis (MVPA) do?

1 mark

Answer 9

Examines pattern of responses across many voxels simultaneously

• achieved by viewing voxel activity pattern as points in multidimensional space

Question 10

What things fall under ‘decoding perceptual experiences’ and ‘decoding other mental states’?

2 marks

Answer 10

• Decoding perceptual experiences: object categories, natural images
• Decoding other mental states: memories, thoughts, lie detection

Question 11

What is a limitation of MVPA studies?

1 mark

Answer 11

• Has limited number of categories but in real life person can have a limitless nuber of thoughts
• Most people have 2 or more thoughts concurrently

Question 12

What is BOLD-fMRI?

1 mark

Answer 12

Blood oxygen level dependent fMRI - reliant on changes in blood pressure

Question 13

What are the characteristics of the basal state of BOLD fMRI signal?

3 marks

Answer 13

• Normal flow
• Basal level (Hbr)
• Basal CBV
• Normal MRI signal

Question 14

What is the activated state of BOLD fMRI?
4 marks

Answer 14

• Increased flow
• Decreased (Hbr)
• Increased CBV
• Increased MRI signal

Question 15

How are conventional fMRI experiments done?

4 marks

Answer 15

• Alternate subject neural state between 2 conditions with sensory stimuli - tasks to perform
• Get MR images repeatedly during process
• Search for voxels that MRI signal time series matches the stimulus time series pattern
• Signal changes due to neural activity are small
• Lengthy computations for signal detection and temporal pattern matching –> data analysis usually done offline

Question 16

If a coma persists for a high period of time, what is this known as?

Answer 16

Permanent vegetative state

Question 17

What is locked in syndrome?
1 mark

Answer 17

• Complete paralysis of al voluntary muscles except eye muscles

Question 18

What is a pseudo-coma?

1 mark

Answer 18

• Patients are awake and conscioud but selectively differentiated - no means of producing speech, limb movement, facial movement

Question 19

What is a reliable way in diagnosing brain damage?
1 mark

Answer 19

Patients need to show some kind of motor signs, active command following

Question 20

Which cortex is hihgly active in subjects in a vegetative state?

2 marks

Answer 20

Precuneus and post cingulate cortex

Question 21

What can be seen in the brain in aloss of ucntionla connectivity and modularity in the vegetatie state?

4 marks

Answer 21

• Effective connectivity impairment in fronto-parietal consciousness network measured at rest
• Residual hippocampal face area activation
• Residual low-level auditory activation disconnected from fronto-parietal netowk
• Residual discconected language network activation

Question 22

Which state shows higher levels of consciousness:

• Locked in state
• Minimally conscious

1 mark

Answer 22

Locked in state

Question 23

What is the pertubational complexity index?

1 mark

Answer 23

Measure of consciousness which combines TMS with EEG and acts on thalamocortical system

Question 24

What form of neuroimaging technique is currently used to see if patients in PVS or MCS show signs of consciousness?

1 mark

Answer 24

EEG