Consciousness
Key Words:
o Consciousness = medically speaking consciousness is the state of the patient’s
awareness of self and environment and their responsiveness to external stimulation
and inner need (Calabro et al, 2015).
o Neural correlate of consciousness = a specific pattern of brain activity that correlates
with a particular conscious experience (Rees et al, 2002).
o Achromatopsia = lack of colour awareness.
o Akinetopsia = lack of awareness of movement.
o Prosopagnosia = inability to recognise familiar faces.
o Free will = the power of acting without the constraint of necessity or fate; the ability
to act on one’s own discretion.
Key Studies:
Laureys et al (2004): coma to a vegetative state to a minimally conscious state to a
minimally conscious state + then confusional state to normative recovery.
Praecuneus and posterior cingulate very important.
Koch et al (2016): is the frontal part of the frontoparietal network important for
consciousness? No, in procedures where the prefrontal cortex has been lesioned it
didn’t affect consciousness. E.g., bilateral frontal lobectomy (Brickner,1952),
bilateral prefrontal resections (Hebb & Penfield, 1940) or disconnection of the
prefrontal cortex and thalamus (Fulton, 1949).
= refocused to a posterior “hot zone” for consciousness.
Milner & Goodale (1995): the majority of visual information is processed
unconsciously. Visual consciousness information processing is dealt with in the
ventral stream.
Logothetis (1998): test of the ventral stream for consciousness, binocular rivalry =
competition for visual awareness, comparing rivalry vs non-rivalry conditions. Found
at the primary visual cortex that cells correlated w20% with non-rivalry, at the
inferotemporal cortex cells correlated 90%.
Tong et al (1998): fusiform face area and parahippocampal place area, different
stimulus = different brain areas activated.
Rees et al (2002): parietal and prefrontal regions were activated when there was a
change in conscious perception.
Bachmann & Hudetz (2014): consciousness occurs when each system fires at an
appropriate level, the relationship is mediated by apical dendrites in pyramidal
neurons in layer 5 of the cortex.
Libet (1985): brain activity precedes conscious free will. Readiness potential is a
surge of electrical activity which is evident in EEG about 500ms before a willed
movement = the brain acts before free will (Schurger et al, 2011 = sceptical).
Fried et al (2011): 12 p’s with epilepsy, wrist flexion task, found a progressive
significant increase in the firing rate commencing well before p’s reported the
Key Words:
o Consciousness = medically speaking consciousness is the state of the patient’s
awareness of self and environment and their responsiveness to external stimulation
and inner need (Calabro et al, 2015).
o Neural correlate of consciousness = a specific pattern of brain activity that correlates
with a particular conscious experience (Rees et al, 2002).
o Achromatopsia = lack of colour awareness.
o Akinetopsia = lack of awareness of movement.
o Prosopagnosia = inability to recognise familiar faces.
o Free will = the power of acting without the constraint of necessity or fate; the ability
to act on one’s own discretion.
Key Studies:
Laureys et al (2004): coma to a vegetative state to a minimally conscious state to a
minimally conscious state + then confusional state to normative recovery.
Praecuneus and posterior cingulate very important.
Koch et al (2016): is the frontal part of the frontoparietal network important for
consciousness? No, in procedures where the prefrontal cortex has been lesioned it
didn’t affect consciousness. E.g., bilateral frontal lobectomy (Brickner,1952),
bilateral prefrontal resections (Hebb & Penfield, 1940) or disconnection of the
prefrontal cortex and thalamus (Fulton, 1949).
= refocused to a posterior “hot zone” for consciousness.
Milner & Goodale (1995): the majority of visual information is processed
unconsciously. Visual consciousness information processing is dealt with in the
ventral stream.
Logothetis (1998): test of the ventral stream for consciousness, binocular rivalry =
competition for visual awareness, comparing rivalry vs non-rivalry conditions. Found
at the primary visual cortex that cells correlated w20% with non-rivalry, at the
inferotemporal cortex cells correlated 90%.
Tong et al (1998): fusiform face area and parahippocampal place area, different
stimulus = different brain areas activated.
Rees et al (2002): parietal and prefrontal regions were activated when there was a
change in conscious perception.
Bachmann & Hudetz (2014): consciousness occurs when each system fires at an
appropriate level, the relationship is mediated by apical dendrites in pyramidal
neurons in layer 5 of the cortex.
Libet (1985): brain activity precedes conscious free will. Readiness potential is a
surge of electrical activity which is evident in EEG about 500ms before a willed
movement = the brain acts before free will (Schurger et al, 2011 = sceptical).
Fried et al (2011): 12 p’s with epilepsy, wrist flexion task, found a progressive
significant increase in the firing rate commencing well before p’s reported the
