5 - Body schema and multi sensory integration I

Question 1

what is Moravec’s paradox?

Answer 1

easy to make computers do reasoning (high-level cognitive)

hard to make computers do perception, action (low-level)

Question 2

what is the body schema?

Answer 2

a representation of the positions of body parts in space, updated during body movement

Question 3

what are characteristics of the body schema?

Answer 3

modular - different body parts processed separately

spatially coded - representation of position of body part in space

updated with movement - automated and continuous tracking of body posture

adaptable - changes when body changes

interpersonal - other’s actions represented within body schema

coherent - spatial continuity, resolves perceptual conflicts

supramodal integration - combines input from multiple sensory sources

MUSICAS

Question 4

what is the peripersonal space?

Answer 4

the space immediately surrounding our bodies

we have special awareness of this, different sense sensitive to different areas

extent not fixed: can contract and expand

Question 5

evidence of peripersonal space

Answer 5

put electrodes in monkey’s brain

elevated response when visual object moves close to hand

response space expands when using tools (tool integrated in body schema)

Question 6

what is body image?

Answer 6

how we imagine and feel about our body?

Question 7

what is the difference between body schema and body image?

Answer 7

body image - conscious representation

body schema - doesn’t require awareness, used for immediate action and action planning

Question 8

what is a distortion of body image?

Answer 8

autotopagnosia
- inability to locate body parts
- loss of spatial unity of body
- action execution is preserved

Question 9

what is a distortion of body schema?

Answer 9

Ideomotor apraxia
- inability to execute actions, especially with tools
- body image is preserved

Question 10

what is a distortion of body schema and image?

Answer 10

Alice in Wonderland syndrome
- distortion in size perception
- body parts may appear smaller or larger than reality
- affects actions to some degree

Question 11

what is the temporal order judgement task?

Answer 11

stimulate both hands in random order
participant then says which hand was stimulated first

Question 12

how does crossing hands effect the temporal order judgement task?

Answer 12

participants accuracy for identifying which hand was stimulated decreases

body schema automatically affected basic perception

Question 13

when does the body schema develop?

Answer 13

6 months

baby looks at foot if squeezed

crossing legs had no effect on performance at 4 months

at 6 months babies become less accurate at identifying squeezed foot in crossed legs condition

Question 14

what is multi sensory information?

Answer 14

the integration of information from multiple sensory sources (e.g. vision, sound, touch)

Question 15

how do we coordinate transformations?

Answer 15

when we convert from one reference frame to another, we need information about the position and orientation of body parts (body schema)

Question 16

evidence in the lab of cross-modal integration?

Answer 16

participants received a tactile and visual stimulus

they responded faster when stimuli were congruent, a congruency effect was found

when arms are crossed congruency effect travels with effected hand

cross-modal interactions mediated by body schema

Question 17

how does body schema change with tool use?

Answer 17

tools incorporated into body schema
cross-modal congruency effects apply during tool use

Question 18

what do arm crossing experiments tell us about the body schema?

Answer 18

affects perception and multi sensory integration