This document summarizes a seminar on dynamic minds that discussed several topics: 1) Studying social interaction through concepts like behavioral matching, entrainment of behavior and brain changes over different timescales. 2) Research on intentional synchronization in tasks like finger wiggling that show different stability for in-phase vs. anti-phase coordination. 3) Studies of unintentional entrainment in behaviors like walking that demonstrate people naturally synchronize without intention.

1. Interacting
minds
II. Dynamic minds
Tommi Himberg
15.11.2017

2. 2
tommi.himberg@aalto.fi
@tijh
mindsync.wordpress.com

3. Seminar series
I) Social minds (2.11.)
II) Dynamic minds (15.11.)
III) Embodied minds (22.11.)
3

4. Schilbach et al. 2013

5. Starting points

6. Studying interaction
• behavioural matching <-> entrainment
• interlinked changes in behaviour/brain, at
different time-scales
• attunement, adaptation, modulation,
coordination, synchrony, matching…
6

7. Dynamics of coordination
• intentional synchrony (Haken, Kelso & Buntz,
1985)
• bimanual oscillation (finger-wiggling)
• order parameter: relative phase φ
• control parameter: frequency of oscillation
• different stability of in-phase & anti-phase
• also observed interpersonally (Schmidt,
Carello & Turvey, 1990)
7

8. Measuring interaction
• focus on the interaction, not participants
• look at the dynamics / temporal evolution
• accuracy / coordination / entrainment
• direction of influence
• enable the emergence of e.g.
“togetherness” => arts-based research
8

9. Entrainment
• “Two independent but connected oscillators
converge in period and/or phase.”
• unintentional; occurs in any social situation
• intentional; foregrounded in music and dance
9(Clayton, Sager & Will, 2004)

10. Entrainment: conditions
• coupling between agents
• autonomy
• flexibility
10
Himberg, 2017

11. Unintentional entrainment
11
Schmidt & O’Brien, 1998
Richardson et al., 2007

12. Gait entrainment
• observation: people often walk in
step when walking side-by-side
• experimental approach: side-by-side
treadmills
• manipulation / investigation of
coupling, intentionality, leg length etc.
Nessler & Gilliland, 2009; Nessler et al., 2012

13. Gait entrainment
13
Intentional entrainmentNot coupled
Nessler & Gilliland, 2009

14. Gait entrainment
14
Normal Mechanically coupled
Nessler & Gilliland, 2009

15. Body sway
15Shockley, Santana & Fowler, 2003

16. Mutual adaptation

17. Mutuality in MT
17Spiro & Himberg, 2014

18. Choir Workshop
18

19. Constant, mutual adaptation
• peak of the sum of CC’s at lag 0 suggests synchronicity
• windowing reveals constant, mutual adjustment
19

20. Phase deviation
per participant
Group entrainment:
Kuramoto model
Order parameter
Mean phase deviation
(Band-pass filtered @ 2 Hz)
20Petri Toiviainen, 2011

21. Cultural effects
21

22. Dynamic attending

23. Dynamic attending
• many environmental stimuli are periodic
• many biological oscillators are entrained to light
(circadian rhythms)
• others entrain to faster rates, to sounds (music,
speech)
• our attentional system take advantage of this by
entraining to these stimuli and focusing more
attention to WHEN we expect things to happen.
Jones 1976, Jones & Boltz 1989, Large & Jones 1999
23

24. Dynamic attending
• attentional resources entrain with the stimulus
• test can be e.g. pitch discrimination
• empirical data agrees with theory
T
attentional
energy
24
stimulus test
time

25. Jones & Boltz 1989 25

26. ARAMEP
• Attentional Resource Allocation in Music
Ensemble Performance (Peter Keller)
• prioritised integrative attending
• (vs. non-prioritised vs. selective)
• splitting attention between own part and
the emerged whole
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27. ARAMEP
• resurssien saatavuus tahdistuneena musiikilliseen
aktiviteettiin metrisen skeeman kautta
Keller 2001
27

28. Eye-tracking attention
28

29. Fixations
• scan path analysis: how we think
influences how we look (Yarbus, 1967)
• locations: viewing paintings, we focus on
faces, hands (social information)
• temporal structure: re-scanning areas
(Anderson et al. 2013)
• coordination of gaze patterns in dyads
(Richardson & Dale, 2005)
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30. Our study
• 24 of participants (14 female, mean age 27) in 12
dyads
• conversation tasks: joint decision-making (choosing
adjectives & naming pictures)
• multimodal recordings: full-body motion capture,
audio-video, (mobile eye-tracking)
➡
30

31. Tasks
• warm-up games, wordgame, 2 adjective
tasks, 3 picture naming tasks (order cb)
• adjective task: “together, choose an adjective
starting with the letter [h…o] that describes [a
cartoon character]
• picture naming task: together, choose a name
for each picture in the plate
• 8 decisions / task, self-paced
• facing & not facing, shared & own plates (+
walking)
31

32. 32

33. Analysis
• CA expert annotated the sequential structure
of the decisions:
• “begin”: participants establish their task
• “middle”: making proposals and discussing
• “end”: committing to the final decision
➡ in analysis, “transitions” and “continuations”
• IRR: 93.7% / junctions timed within 1s: 89.6%
• movement data: quantity of motion,
synchronisation of the QoM
33

34. 34

35. 35

36. Eye-tracking
36

37. 37

38. 38
%

39. Preliminary results
• partner responds to proposal with gaze -
most probably when the proposal is
accepted, less frequently when they
eventually reject the proposal
• mutual gaze rarest when proposals get
ignored
39