Consciousness

Question 1

Define consciousness

Answer 1

State of being aware responsive to the surrounding, dynamic between awareness and vigilance

Question 2

Describe the mechanisms of consciousness

Answer 2

The reticular activating system projects to the hypothalamus, thalamus and cortex. The ventral tegmental area - midbrain (dopamenergic) and locus coeruleus - pons (noradernergic)

We can quantify brain activity via transcranial magnetic stimulation and EEG and mapped on perturbational complexity index (PCI)

Neural correlates of consciousness is the minimum neuronal mechanisms jointly sufficient for any one specific conscious experience.

Question 3

Describe the disorders of consciousness

Answer 3

1. Coma - stare of unstable unresponsiveness, lasting more than 6 hours in which a person cannot be awakened and fails to respond to painful stimuli, lacks normal sleep wake cycle and doesn’t initiate voluntary action
2. Vegetative state - wakefulness without awareness in which there is preserved capacity for spontaneous arousal, evidenced by sleep wake cycle and reflexive behaviour and spontaneity. Destruction of cortex and hemisphere (intact RAS)
3. Minimally conscious state - a state of severely altered consciousness in which minimal but clearly discremble behaviour of self environment is evident
4. Locked In syndrome: damage to ventral pons
5. Brain stem death