Week 2: the brain

mind and brain are identical (consciousness=brain activity)

quali don't exist, understanding of the mind is wrong. mind=brain (since qualia of the mind don't exist)

neural activity alone can't provide answers. need to take body and environment into account

can never understand consciousness (not possible for humans)

sensory and motor neurons that run through spinal cord and brainstem

spinal cord and brain

brainstem (controls: cardiac, respiratory and sexual functions)

motor control

relay areas for sensory inputs

• thalamocortical loop

involved in pain desensitisation and forms reticular activating system (sleep-wake transitions)

reticular formation role for consciousness

regualtes autonomic nervous system

plays role in emotion, pain and motivational responses

expanded more than any other brain structure during human evolution

• no ultimate top

• interlinked system

two main types of neurons running through neocortex

sensory association areas, somatosensory cortex and dorsal stream

auditory, memory, ventral stream

animal studies. microelectrode inserted into neuron and records activity

measure an aspect of neural functioning and correlate it with conscious experience reports

conscious perception is compared to unconscious perception

rivalry in vision

• binocular rivalry

different images are presented to each eye resulting in perception flipping between both eyes

• both images compete for consciousness

(Francis Crick) front of the brain is observing sensory areas with many zombie modes of processing all over brain

• contain transient groups of neurons corresponding to thoughts, images and perceptions

locatable part of brain, crossing point for matter and consciousness (1980s)

• neural activity here is sufficient for visual consciousness (elsewhere isn't)

don't contribute to phenomenal experience

• all unconscious info is necessary precursor for conscious experience (not responsible for it tho)

NCCs of visual consciousness comprise of many diff areas associated with vision working together

giving attributes to parts of a person/thing than can only be given to person/thing as a whole

where were conscious visual experiences correlated with instead of V1 or early parts of sensory pathways?

dominant image inhibits the other (suppressed image)

• weakened as neurons become habituated to dominant image (suppressed image becomes dominant)

blocking at thalamus level (disconnect similar to PVS)

thalamus

antagonist of NMDA receptor, blocks normal excitatory effect of glutamate

• anesthetic

conscousness increases and decreases with integration of info in brain

inability to remember source of knowledge.

• related to unconscious plagiarism

false belief of having invented an idea when it was actually learned from someone else

thoughts can arise from two diff processes: conscious or unconscious

• contrasts automatic processing vs controlled

transition from unconscious to conscious is influenced by level of processing required by task

physical and metaphorical place where conscious experience takes place

• ideas, images, feelings we are consciously aware of are presented

discarding Descartes' dualism, but fail to discard imagery of central (but material) theatre

mutual interactions between several areas (no 'top' can be located/ no where can we say consciousness happens 'here')

incorrectly associate observing similarities between imagery and vision with saying pictures in the brain are painted on a mental canvas

mental imagery is language-like

when we imagine, sensory exploration is performed without any interaction with environment

potential for sensory exploration is enough for imagination

• imagining/seeing depends on bodily engagement with environment

no info has to become conscious and a collection of specialised unconscious processors competes for access to GW

cut off piece of cortical tissuel, if activated communication would take place in form of field that doesn't depend on nerve pathways

how features from diff circuits can be combined for perception

what makes binding possible

what is the primary role of synchrony?

neurons representing 1 object fire in synchrony with each other, but out of synchrony with neurons representing other objects simultaneously

consciousness is the capacity of a system to integrate info

integrated cross-modal perception

produces plausible explanations for RH's actions

what two brain functions were studied on SB patients (MacKay)

unconsciously control goal-directed activities and evaluate them in terms of priorities

determine and update priorities evaluated by executive levels

dissociation between performance and consciousness

• conscious but stuck in present, disconnected from past

inability to form new LT memories

inability to have LT memories of past events