Multisensory integration - body schemas Flashcards
what tasks are seemingly easy for humans that are difficult for robots?
reaching, grasping, manipulating objects
what tasks are seemingly hard for humans that are easy for robots?
playing chess, solving logic puzzles
how are computers good at hard tasks?
use inference, pick best pathway from list of different objects, basic strategy
basic sensorimotor skills are hard to do with AI but its easy to make computers exhibit adult level performance on intelligence tests/playing chess. what paradox is this?
Moravec’s paradox
what senses are needed to light a match?
vision and touch
what 2 senses provide multi sensory integration?
vision and touch
for what type of tasks do we need to integrate information across different senses?
motor tasks
reference frame from vision =-
eye centred, retinal
reference frame for audition =
head centred, location of sound source with respect to ears
reference frame for touch =
body centred, location of tactile stimulus on skin
we need to convert between _______ ______ and to _____ ______
reference frames, external space
to get from an eye centred reference frame to a head reference frame what do you need to know?
the relative angle between the 2 frames > causes a shift in reference frame
eye > head = need to know orientation of?
eyes
head > body = need to know orientation of?
head
what required knowledge is needed to convert between reference frames?
relative position and orientation of body parts
relative position of body parts is called what?
body schema
what are the features of the body schema?
spatial coded, modular, updated with movement, adaptable, coherent, interpersonal
what happens every time we move?
our body schema is updated instantly
position of each body part in external space =
spatial coded
how do we know that the body schema is modular (different body parts processed in different brain regions)?
there are selective impairments for different body schemas
how is the body schema adaptable?
it changes when the body changes > with age, changes get incorporated into the body schema over time
how is the body schema coherent?
resolves perceptual conflicts between different senses > spatial continuity
observed actions are represented within the same body schema =
interpersonal
what are the 3 types of body representation?
body schema, body image, body semantics
sensorimotor representation that guides action =
body schema
i can feel that i have a body =
body percept
awareness of what the body looks like/is made up of =
body concept
names for the different body parts =
body sematics
what type of task did Heed & Azanon (2014) conduct to see if body posture affects perception?
temporal order judgement task
what were the findings from Heed & Azanon’s study?
ppts did worse when arms crossed as body schema interfered, they mixed up which hand was stimulated when arms crossed
when does the body schema start to develop?
6 months
at 6 months the body schema starts to interfere with what?
tactile orientation
what were the results from Begum ali et al, 2015 study on babies body schemas?
at 4 months no difference when feet were crossed (no inference) at 6 months more correct responses when feet were uncrossed (50% chance of correct reach > showed interference from body schema)
do incongruent or congruent distractors lead to longer reaction times?
incongruent
delay =
incongruent reaction time - congruent reaction time
cross modal congruency was shown when a delay was due to ?
a visual distractor
distractors lead to _____ delays
response
same hand distractors lead to _______ delays than different hand distractors
longer
the space immediately surrounding our bodies =
peripersonal space (PPS)
objects within this can be grasped and manipulated immediately, not fixed (can contract and expand) =
PPS
PPS can change depending on what 2 things?
environment, body posture
what can be incorporated into the body schema during use to extend the body?
tools
what effects also apply during tool use?
cross modal congruency effects
when the tools are crossed (not arms) the _____ delay effects are seen during arm crossing. This shows tools become part of ______ _____
same, body schema
list some of the disorders of body schema
Alice in Wonderland syndrome, autopagnosia, finger agnosia, phantom limbs
distortion of size perception that can affect the whole body=
alice in wonderland syndrome
body parts might appear smaller =
microsomatognosia
body parts might appear bigger =
macrosomatognosia
what is alice in wonderland syndrome associated with?
childhood and migraines
inability to locate body, loss of spatial unity of body, patients know body parts but not how they fit together =
autopagnosia
fused percept of fingers and no concept of individual fingers =
finger agnosia
after limb loss presence of limbs still felt, includes agency over limb =
phantom limbs
what are phantom limbs associated with?
pain
how can phantom limbs change in size over time?
shrink, telescoping (body schema is not updated correctly)
what is the neural basis of the body schema?
cross modal neurons
neurons respond to both ______ and ______ stimuli
visual, tactile
how are tools reflected in neural responses?
expansion of PPS during tool use
