conciousness cog neuro lecture/slides

abilities that do not need conciousness

sequence completion,

recognizing grammatical errors,

size and shape constancy (edge/shadow/color detection as part of recognition, ex recognizing a christmas tree)

priming

Taylor and McClosky (circle/square)

CONCLUSIONS: the brain processes stims that we are not conciously aware of and makes action based on those stims (which we are not concious of either), when we unconciously execute those actions, the brain then makes up an elaborate story to explain it

METHODS: circle and square on screen at diff times, circle= left hand square= right hand, circle appears for a split second, then is covered by square

brain unconciously processes circle and provides an unconcious left hand response, but then processes square and provides a concious right hand response correction

when asked why the person showed the left handed response first they make up a story

Pisella et al (moving dots)

CONCLUSIONS: parietal lobe has more control than our concious decision making an override, even when we conciously know not to reach for the second dot location people still cannot stop themselves

METHODS: participants are instructed to move hand to dot as fast as possible when it appears, some trials it appears and then moves as soon as the participants make the first movement,

healthy patients cannot control their automatic correction prodecure in post parietal lobe to move their hands to where the dot is the second time, thus they correct their reach to the second dot

nonconcious processes

are intelligent and can coordinate activity,

conciousness not involved in most perceptual or cog processes, deals with the outcomes of these processes

Libet (somatosensory delay)

CONCLUSIONS: somatosensory inputs take 500 msecs to be concious of (1/2 a second)

METHODS: touched the patients toe, then stim on the somatosenory cortex over the arm within 500 msec→ patient reports that you touched their arm,

touched patients toe, them stim somatosensory cortex over the arm after 500 msecs, patient reports that you touched their arm and their toe

Libet (decision making delay)

CONCLUSIONS: conciousness is not involved in decision to execute action

METHODS: told participants to look at clock and move their hands whenever they wanted to, but take note of when they made the concious decison to move,

200 msec gap between when they made the decision and when they moved

350 msec gap between when the neural activity over the motor area for the hand started and when they conciously made their decision

So, 550 msec gap between when neural activity started and they moved

Soon et. al.

CONCLUSIONS: conciousness is not volition, cannot initiate motions

METHODS: told participants to move their hand anytime they want and report what letter was displayed on a screen (changes every 500 msec), tracked brain activity on fMRI

right before movement the M1 and ant. cingulate light up,

the frontal pole and the post cingulate light up 8 seconds before your decision is made

what is conciousness

rationalization made up by language system to rationalize illusion of control

when SMA is lightly stimmed, participant response is that they feel like they want to move

When SMA is medium stim, patient response is that they feel like they need ot move

When SMA is strongly stimmed, patients move and asked why they say becuase they decided to do so

split brain

right hemisphere is completely indepedent from left hemisphere,

visual info on left side goes to right hemisphere, and vice versa

No language on the right side, only left,, so right cannot express anything it is seeing verbally and the left cannot express anything that the right is processing (stim in the left visual field)

Gazzinga

CONCLUSION: the language system of our brain makes up a narrative to rationalize our unconcious processing

METHODS: showed split brain patients a different stim in each visual field, then gave them associated options to point to

snow storm in the left visual field (right hemisphere, left hand), chicken foot in the right visual field (left hemisphere, right hand), left hand points to a shovel and right hand points to a chicken

when asked why they are pointing to a shovel and a chicken, patients make up a story based on the chicken stim because the language area only knows of that stim (not the snow storm because it is being processed ONLY by the right hemi)

Eagleman and Sejnowski

CONCLUSIONS: the brain predicts where a moving object will be next, does this because there is a 80msec delay from real time and concious time (aka the time that a stim hits your retina and moves through your visual processing)

METHODS: participants were shown a moving stim, then a flash that was aligned with the moving stim, then asked where the flash was in relation to the moving stim, flash lag effect→ saw the moving dot as ahead of the flash even though they were in line with each other

conciousness definiton

subjective impression we have of the internal and external worlds

types of conciousness

awareness of sensory qualities, awareness of things (position/presence), and awareness of self

dualism vs monoism

dualism (Descartes) said that the body is seperate from the soul, and that the body was like a machine controlled by the soul (or mind)

monoism is the idea that mind and body are one, nothing exists except energy and matter

psychophysics

how our concious perceptions differ from/agree with reality