Embodiment: Body schema, body ownership and agency Flashcards
Body ends and enviro begins
factors effecting
Facilities change this this e.g. car
can be inaccurate e.g. body dysmorphia
Body schema
Peripersonal space- space around us we consider part of ourself
usually about as far as you can reach
Neurons fire for face, hands and Peripersonal space
needs to be able to map together - multisensory and visual. extend how far away trigger by extending out to reach
Laws of multisensory integration
spatial- closer in ocular space
temporal- occur close in time
inverse effectiveness- integration stronger when signal is weaker
Peripersonal space and body dysmorphia
ppts walk down to table and grab something
doors change in width with each step
don’t slow down if narrower just turn shoulders (25% bigger then shoulder width)
Anorexia- turn at 40% bigger then shoulders
Multisensory integration of body signals and body self consciousness
proprioceptive signals impact multisensory integration but need to define position of the body in space and whether stimuli is related to body
Four constraints
Proprioceptive
body-related visual info
relation to PPS
embodiment
Rubber hand illusion
test via how close and orientation of it to trick brain
visual and and tactile matched then do (integration doesn’t happen)
x- too far away and different directions
Body swap illusion
3D camera think are dummy
react when stabbed with knife
Body location study
change where person thinks they are
see back 2 meters in front of where they are
feel touch at where viewing it rather then on back
doesn’t work if not person or different orientation
Self begins with the body
when look in mirror see as self
experience of body is both physical and psychological
bodies ground our relations
Sense of body ownership
feeling of mine-ness that we perceive toward our body parts, thoughts or feelings
sense of agency
experience of initiating and controlling an action
Alien hand syndrome
hand acts against brain
Involuntary movements
no motor commands and no volitional processes
Limb ownership and agency
Anosognosia - hemiparesis or hemiplegia (weakness/paralysis) after right sided stroke with disturbed sense of agency
unaware of lack of agency
insula very small area
disturbed sense of ownership
insula activated during rubber hand illusion
Implicit measure of sense of agency
volentary action without asking about expirences instead judge time
intentional binding effect
effect of sensory outcome
shorter time then when observe someone else
Explicit measure of sense of agency
Questionnaire how much contribute to task or experience of agency during task.
Helping hand experiment
hand movements manipulated from behind
feedback vs no feedback
if know what’s going to happen then increased feeling of agency
Wheel of fortune study
priming of potential action incites agency
don’t know if you or computer move square.
if it stops where you think it stops then think its you
Figuring out if its your hand study
do a movement and see the movement on screen
ppts and experimenters hand appear at different angles on the screen
figure out whether its your own hand
can do if different movement and same direction
can’t if same movement, different directions and complete opposite
things effecting are timing, direction, orientation and type of movement
Efferent info
if efferent info available then more sensitive to ownership
sense of agency model
if outcome is same as predicted or is the desired outcome then feel sense of agency
if not then no agency felt or attributed to external things
Sense of agency areas in the brain
cerebellum - motor refinement
cingulate cortex
SMA (support motor area)
dlPFC
PPC
Gait and sense of agency
current state, model of sensory output and feedback
sensory error
model of limb dynamics > predict where next step is.
If step is not okay use corrected visual feedback
test by shifting view to one side and see how much they correct
distant vision and walk straight ahead towards target
if discrepancy too big then realise what have been done
