Effects of biological relevance of the stimulus in mediating spontaneous visual social coordination

0

5

10

15

20

-
200

-
100

0

Time Series

0

1

2

3

4

5

0

2

4

x 10

4

Spectra

Amplitude

1.4 Hz

IN#001.JLD

0

5

10

15

20

-
200

-
100

0

0

1

2

3

4

5

0

2

4

x 10

4

Amplitude

0.9 Hz

IN#002.JLD

0

5

10

15

20

-
200

-
100

0

0

1

2

3

4

5

0

2

4

x 10

4

Amplitude

1 Hz

IN#003.JLD

0

5

10

15

20

-
200

-
100

0

0

1

2

3

4

5

0

2

4

x 10

4

Amplitude

1.2 Hz

IN#004.JLD

0

5

10

15

20

-
200

-
100

0

0

1

2

3

4

5

0

2

4

x 10

4

Amplitude

1.35 Hz

IN#005.JLD

0

5

10

15

20

-
200

-
100

0

0

1

2

3

4

5

0

2

4

x 10

4

Amplitude

1.8 Hz

IN#006.JLD

0

5

10

15

20

-
200

-
100

0

Time [sec]

0

1

2

3

4

5

0

2

4

x 10

4

Frequency [Hz]

Amplitude

2.2 Hz

IN#007.JLD

Effects of biological relevance of the stimulus

in mediating spontaneous visual social coordination

G.C. De Guzman; E. Tognoli; J. Lagarde; K.J. Jantzen; J.A.S. Kelso

Center For Complex Systems and Brain Sciences, Florida Atlantic University, Boca Raton, FL,
USA


The

efficacy

of

the

stimulus

combinations

were

assessed

using

the

stimulus
-
hand

relative

phase

and

a

similarity

index

measure

of

coupling

strength

(
Bhattacharya

et

al
.
,

2003
)
.

Individual

trials

exhibit

phase
-
locking

interspersed

with

phase

drifts

indicating

tendencies

to

synchronize
.

When

collapsed

across

trials,

the

phase

distributions

showed

no

difference

between

conditions
.

The

similarity

index

showed

that

coupling

between

subject

and

stimulus

was

strongest

when

the

latter

was

an

image

of

a

hand

driven

by

real

movement

data
.

The

weakest

coupling

occurred

when

the

stimulus

was

a

dot

image

moving

in

sinusoidal

manner
.

crosshair
s
image
animated
s
crosshair
s
15
15
15
on
presentati

Stimulus



Introduction

While executing self
-
paced rhythmic finger flexion
-
extension, subjects view
on a monitor either the movement of a finger (H) or an oscillating dot (D) for
15 seconds. To establish the self
-
paced rhythm, the viewing phase was
preceded by an initial 15 second interval during which the subjects oscillate
their index finger while viewing a central fixation cross. The stimulus
movement frequency was fixed at either 10% below or 10% above the
subject's self
-
paced rate as determined at the start of the experiment. A total
of 32 trials ([hand,dot]x[sine,data]x[high frequency,low frequency]x4 trials)
were collected.

Motion characteristics

●

Hand movement data

●

Perfect sinusoidal

●

±

10% subject frequency


Q
:

Is

behavioral

coupling

during

spontaneous

social

coordination

facilitated

by

the

perception

of

biologically

relevant

stimuli?

The

effects

of

a

biologically

realistic

agent

and

movement

are

compared

to

a

non
-
biological

stimulus

and

a

synthetic

motion
.

If

the

perception

of

a

functional

homology

(putatively

producing

an

embodied

response)

is

not

important

for

promoting

spontaneous

coordination

between

agents

then

all

stimuli

and

motion

types

should

elicit

the

same

behavior
.

Otherwise,

biologically

constrained

stimuli

should

produce

stronger

behavioral

entrainment
.


Experiment

Analysis

Bhattacharya,

J
.
,

Pereda,

E
.

&

Petsche,

H
.

(
2003
)
.

Effective

Detection

of

Coupling

in

Short

and

Noisy

Bivariate

Data
.

IEEE

Transactions

on

systems,

man,

and

cybernetics

–

Part

B
:

Cybernetics
,

33
(
1
),

85
-
95
.

Kilner,

J
.
M
.
,

Paulignan,

Y
.

&

Blakemore,

S
.
J
.

(
2003
)
.

An

interference

effect

of

observed

biological

movement

on

action
.

Current

Biology,

13
,

522
-
525
.

Oullier,

O
.
,

de

Guzman,

G
.
C
.
,

Jantzen,

K
.
J
.
,

Lagarde,

J
.
F
.

&

Kelso,

J
.
A
.
S
.

(
2004
)
.

Spontaneous

interpersonal

synchronization

is

modulated

by

the

degree

of

visual

coupling
.

Journal

of

Sport

and

Exercise

Psychology,

26
,

S
13
.

Sebanz,

N
.
,

Knoblich,

G
.

&

Prinz,

W
.

(
2003
)
.

Representing

others'

actions
:

Just

like

one's

own?

Cognition,

88
,

B
11
-
B
21

Preliminary results

Similarity Index

Supported by NIMH Grant MH42900

The

similarity

index

(see

e
.
g
.

Bhattacharya,

Pereda

&

Petsche,

2003
)

uses

state

space

reconstruction

techniques

to

assess

strength

of

directional

effects
.

In

tightly

coupled

systems,

the

N
-
nearest

neighbors

of

a

point

x(t
k
)

in

X

and

the

N
-
nearest

neighbors

of

the

point

y(t
k
)

in

Y

have

similar

time

indices
.

F o r

u n c o u p l e d

s y s t e ms,

t h e r e

is

a

high

probability

that

the

set

of

time

indices

for

X

is

very

different

from

the

time

indices

for

Y
.

The

collection

of

points

in

X

at

times

corresponding

to

the

Y
-
time

indices

is

called

“mutual

neighbors”
.

An

instantaneous

measure

of

the

similarity,

S
k
(X|Y),

is

then

the

radius

of

the

cloud

of

R
-
nearest

neighbors

divided

by

the

radius

of

the

cloud

of

R
-
mutual

neighbors
:

S
k
(X|Y)

measures

the

effect

of

Y

on

X
.


Similarity index

Pilot study: 4 Ss

A/D: OPTOTRAK @ 100 Hz

1
2
3
4
0
0.5
1
1.5
2
2.5
3
3.5
4
x 10
-3
1
2
3
4
0
0.5
1
1.5
2
2.5
3
3.5
4
x 10
-3
Hand
Dot
Data
Sine
Hand
Dot
Data
Sine
S2: Mean Sim Index - LO
S2: Mean Sim Index - HI
1
2
3
4
0
0.5
1
1.5
2
2.5
3
3.5
4
x 10
-3
1
2
3
4
0
0.5
1
1.5
2
2.5
3
3.5
4
x 10
-3
Hand
Dot
Data
Sine
Hand
Dot
Data
Sine
S2: Mean Sim Index - LO
S2: Mean Sim Index - HI
1
2
3
4
0
1
2
3
4
x 10
-3
1
2
3
4
0
1
2
3
4
x 10
-3
S3: Mean Sim Index - LO
S3: Mean Sim Index - HI
Hand
Hand
Dot
Data
Sine
Sine
Data
Dot
1
2
3
4
0
1
2
3
4
x 10
-3
1
2
3
4
0
1
2
3
4
x 10
-3
S3: Mean Sim Index - LO
S3: Mean Sim Index - HI
Hand
Hand
Dot
Data
Sine
Sine
Data
Dot
-180
-90
0
90
180
0
200
400
600
800
1000
RG: Hand (Fast Stimulus)
-180
-90
0
90
180
0
200
400
600
800
RG: Dot (Fast Stimulus)
-180
-90
0
90
180
0
200
400
600
800
1000
RG: Sine (Fast Stimulus)
-180
-90
0
90
180
0
200
400
600
800
RG: Data (Fast Stimulus)
Relative Phase Distribution
-180
-90
0
90
180
0
200
400
600
800
SS: Hand (Fast Stimulus)
-180
-90
0
90
180
0
200
400
600
800
SS: Dot (Fast Stimulus)
-180
-90
0
90
180
0
100
200
300
400
500
600
SS: Sine (Fast Stimulus)
-180
-90
0
90
180
0
200
400
600
800
SS: Data (Fast Stimulus)
Relative Phase Distribution
0
500
1000
1500
-40
-20
0
20
40
0
500
1000
1500
-40
-20
0
20
40
S2
–

Trial 15
-

hdL

0
500
1000
1500
-40
-20
0
20
40
0
500
1000
1500
-40
-20
0
20
40
S2
–

Trial 12
-

dsL

Perturbation effects

More

Less

These

preliminary

results

suggest

that

embodiment

can

occur

when

coordinating

with

a

virtual

partner

and

the

quality

of

the

interaction

depends

on

the

biological

relevancy

of

the

stimulus

presented

to

the

other
.

Motion

variability

produces

a

stronger

coupling

effect

than

visual

(anatomical)

accuracy

in

this

synchronization

task
..

This

is

easily

evident

from

the

perturbations

induced

by

real

hand

as

compared

to

synthetic

movements
.

That

a

realistic

hand

figure

driven

by

a

real

movement

data

elicits

strong

coupling

is

consistent

with

studies

that

showed

mere

observation

of

movement

of

another

person

affects

motor

responses

strongly

enough

to

interfere

with

one’s

execution

of

a

similar

action

(Sebanz,

Knoblich,

&

Prinz,

2003
)
.

Additionally,

studies

showed

that

with

a

movement

stimulus

generated

by

human
-
figured

robots,

the

interference

is

less

noticeable

(see

e
.
g
.

Kilner,

Paulignan,

&

Blakemore,

2003
)
.


Summary

Relative phase