Recall how Ayesha takes a glass and holds it up while Beatrice pours prosecco;
and unfortunately the prosecco misses the glass, soaking Zachs’s trousers.
Ayesha might say, truthfully, ‘The collective goal of our actions was not to soak Zach's trousers in
sparkling wine but only to fill this glass.’
What could make Ayesha’s statement true?
As this illustrates,
some actions involving multiple agents are purposive in the sense that
a clue: when agents perform joint actions, motor representation concerning
a partner’s action can occur.
a clue:
motor representations concerning
another’s actions occur in joint action
An important clue as to how we might be in the ‘we mode’ is provided by some experimental
data concerning motor representation in joint action ...
Kourtis, Sebanz, & Knoblich (2013)
The CNV, an event-related potential, is a signal of motor preparation for action which is time-locked to action onset.
In this research, Kourtis et al show
that the CNV occurs when joint
action partners act, suggesting that when acting together we represent
others' actions motorically as well as our own,
and also that the stronger CNV peak is correlated with better coordination
(Kourtis et al., 2013);
and in earlier research they show, roughly, that a stronger CNV occurs
in relation to actions of others one is engaged in joint action than in
relation to actions of others one is merely observing
(Kourtis, Sebanz, & Knoblich, 2010).
Kourtis et al. (2013)
Kourtis et al. (2013, p. figure 5)
‘the (motor) CNV of a “receiver” peaked approximately at the time of the partner’s response. This suggests that in the receiving 610 condition participants were not only preparing their own actions but also sampling the average speed their partner took to initiate the giving action. This, in turn, allowed them to predict the time their partner would
take to initiate the giving action on a given trial.’
(Kourtis et al., 2013, p. 9)
‘there was a significant correlation between the receiver’s motor CNV
amplitude and the improvement in coordination. The behavioral analysis clearly showed that the speed-up
in receiving led to the improvement in coordination
as receiving was getting faster at a greater rate than giving. This finding can be well explained by the assumption that motor simulation allowed the receiver 655 to predict the timing of the giver’s action and to improve coordination by decreasing the asynchrony in action onset between initiating the giving and receiv-
ing action.’
(Kourtis et al., 2013, p. 9)
Kourtis, Knoblich, Woźniak, & Sebanz (2014, p. figure 1c)
I think we're a long way from having a large body of converging evidence for this conjecture,
but there is some that points in this direction.
One of the most relevant experiments is this one by Kourtis et al. (2014).
They contrasted a simple joint action involving two agents clinking glasses.
The CNV is a signal of motor preparation for action which is time-locked to action onset.
In previous research, Kourtis et al show (i) that the CNV occurs when joint action
partners act, suggesting that when acting together we represent others' actions motorically
as well as our own (Kourtis et al., 2013);
and
(ii) (roughly) a stronger CNV occurs in relation to actions of others one is engaged in joint action than
in relation to actions of others one is merely observing (Kourtis et al., 2010).
Kourtis et al hypothesised that in actions like clinking glasses,
A single outcome represented is motorically,
which triggers planning-like processes
concerning all the agents' actions.
This leads to the prediction that the CNV in joint action will resemble that occurring in
bimanual action more than that occuring in unimanual action.
Kourtis et al. (2014, p. figure 4a)
... and this is exactly what they found.
Ramenzoni et al, 2014 figure 1
Importantly there is converging evidence for the involvement of motor representation concerning
a partner’s action in joint action from studies which use behavioural measures ...
Joint performance is better when observing joint actors; individual performance when observing
individual actors.
Ramenzoni et al, 2014 figure 1
Ramenzoni et al, 2014 figure 1
So once again we are forced to ask,
What are those motor representations doing here?
Sacheli et al, 2018 figure 2 (part)
Sacheli et al, 2018 figure 5
[Skip -- just in case anyone asks]
Sacheli et al, 2018 figure 3
Conjecture:
Collective goals are represented motorically.
Prediction 1 (della Gatta et al, 2017):
Framing two agents’ simultaneous unimanual actions as joint can induce effects similar to bimanual coupling.
Prediction 2 (Sacheli et al):
Framing two agents’ sequential actions as a joint action modulates the effects of ‘incongruent’ actions.