S2W8Consc Flashcards
(41 cards)
Dualism
Mind exists independently of the brain.
Descartes.
Mind and matter.
Mind has attribute of thought and matter has spatial extension.
How do they interact?
I think, therefore I am
Cogito ergo sum
Descartes.
The act of doubting own existence is proof of the reality of one’s own mind (must be a thinking entity)
Idealist
Mind controls the body.
Only mental phenomena exist
Mind arises from the brain.
For every mental event there is corresponding brain event
Koch
Wrote a book that discusses consciousness.
Neuromorphic
Computational
Use of very-large-scale integration (VLSI) systems containing electronic circuits to mimic the nervous system.
Implement models of neural systems (for perception, motor control, or multisensory integration)
Neuroprosthetic
A device that can monitor and decode the electrical language of thoughts and convert into overt machine control (limbs).
Conscious content
Information we are aware of at any given moment.
Characterised by experience of perceptions, thoughts, feelings and awareness of the world.
Conscious level
State of consciousness
From coma through to alert wakefulness
Phenomenal consciousness
Feelings, sensation in the present moment
Access consciousness
Ability to reason, reflect and have a sense of self, that extend beyond the current moment.
Chalmer (2007) hard and easy problems
The hard problem:
Why should physical processing give rise to a rich inner life?
Easy problem:
Understand our ability to discriminate and categorise stimuli, integrate information, and access our internal states and control our behaviour.
Functions of consciousness
Perceiving the environment
Social communication
Controlling our actions
Allows us to think about events and issues far removed from the present
Integrating information
Subliminal perception
Debner and Jacoby (1994)
Word presented for 50 or 150 ms followed by a mask.
Then the first 3 letters of the word presented again.
Think of first word that came to mind starting with those letters, except for the word that had just been masked.
150 ms: participants followed instructions to avoid using masked word.
50 ms: masked word was often.
Proof reading task
IV1: Unconscious goal: with socialisation-relevant words
or not.
IV2: Socialisation seen as important or not.
DV: errors detected in text.
Unconscious socialisation goal impaired proofreading performance in participants for whom socialisation is an important goal.
Social communication
Developing conscious awareness of ourselves helps us to understand other.
Temporo-parietal junction used for this function.
Possible that awareness originally developed to understand others and only later did we develop self-awareness.
Controlling our actions
Free will is an illusion. Our actions are caused by unconscious process.
Wegner argued that the principle of priority, consistency and exclusivity jointly lead us to believe our actions are caused by our conscious thoughts.
When a thought appears in consciousness just before an action (priority), is consistent with the action (consistency) and is not accompanied by alternative causes of action (exclusivity), we experience conscious.
Libet free will
Measured the time when subject became consciously aware of decision to move.
Dot on screen of oscilloscope circulating rapidly.
Subject noted position of dot when he was aware of conscious decision to move.
Conscious awareness preceded finger by 200ms BUT
Readiness potential 550ms before wrist.
Uunconscious activity 350ms before reporting conscious awareness .
Bode et al. 2011 free will
fMRI Left fronto-polar cortex
Outcome of free decisions can be decoded above chance from brain activity several seconds before reaching conscious.
Shows some of our decisions are prepared preconsciously before we are aware.
However:
Requirement to make random responses probably reduces any pre-decision conscious processing.
Researcher’s ability to predict participant decision only slightly above chance.
Assessing consciousness
Actual conscious experience is much richer than our ability to report it.
Reports of conscious experience limited due to processes (e.g. memory) intervening in between experience and report.
Distinction between objective or subjective thresholds.
Under-reporting of visual arrays (Sperling, 1960)
Whole-report condition: presented subjects with 50ms presentations (then mask) of visual arrays of letters and found that on average they reported back 4.4 letters.
Partial-report condition: gave subjects an auditory cue to identify which row they would have to report. They were able to report 3.3 letters in that row.
Delayed the presentation of the auditory cue to 1 second: subjects’ recall fell to about 1.5 letters.
Recall fell to third of whole report (3 rows), so were able to report as many items from cued row as they encoded without cue.
Indicates subjects have all letters in a visual buffer but they have difficulty in reporting them before they decay.
Coma
Person shows no signs of being awake and no signs of being aware.
Doesn’trespond to their environment, voices or pain.
Lasts for less than two to four weeks.
Vegetative state
Person is awake but is showing no signs of awareness.
May open their eyes, wake up and fall asleep at regular intervals and have basic reflexes, such as blinking.
Able to regulate heartbeat and breathing
No meaningful responses, such as following an object with their eyes or responding to voices.
No signs of emotions.
Continuing vegetative – more than 4 weeks
Permanent vegetative – more than six months if non-traumatic injury, more than 12 if traumatic injury
Minimally conscious state
Shows clear but minimal or inconsistent awareness
Periods where they can communicate or respond to commands, such as moving a finger when asked.
May enter after being in a coma or vegetative state.
Some cases it is on the route to recovery, but others it’s permanent.
Continuing: 4 weeks+
Permanen: depends on injury and response but several years+
Cruse (2011) conscious states
EEG signal associated with motor imagery on one healthy control and three patients.
Clear focal areas over the hand and toe motor areas (directly relevant to the task) for all four participants.
Shows activation even in a coma
