online handout
Motor Mindreading?
[email protected] & [email protected]
Cecilia’s talk is about narrowing down the potential functions of mirror neurons
and stepping back from some of the wildest ideas about their roles in our lives.
My aim in this talk is to complement hers by
suggesting that there may be a further function for
mirror neurons.
Building on the her agreement that mirror neurons may be involved in tracking others’ actions,
I want to suggest that there is a case for the view that they are also involved in
tracking others’ mental states.
Wurm & Lingnau (2015, p. figure 1, part)
mirror activation contingent on correctness of the action
NB: effect observed in pianists but not in non-pianists who were trained to detect
the errors
Candidi, Maria Sacheli, Mega, & Aglioti (2014, p. figure 1)
Point here is just that mirror activation contingent on correctness of the action.
But if had more time could also say that the timing issue is important (and
Wurm & Lingnau (2015) are not getting at timing) because Candidi distinguish early
mirror responses (not sensitive to correctness) from later mirror responses.
Good review and commentry in (Naish, Houston-Price, Bremner, & Holmes, 2014)
[Cecelia might argue that there’s low spatial resolution. But the muscle-specific responses
indicate that motor processes are certainly involved.
Can also counter that low temporal resolution of fMRI may be a limiting factor]
[figure text]
‘Figure 3. The left panel of the figure shows the significant
interaction of response and muscle factors where the facilitation of
corticospinal excitability found for Hit trials was restricted to APB
and did not expand to the other muscles. The right panel of the figure
shows the significant interaction between response and time factors in
pianists where the facilitation of the corticospinal excitability
during Hit trials was absent 100 ms, was clearly significant 300 ms,
and was still present as a strong trend 700 ms after error
observation. Mean ± standard error mean (SEM).’
Some markers of motor representation ...
1. are unaffected by variations in kinematic features but not goals
Cattaneo, Sandrini, & Schwarzbach (2010) showed participants ‘adapting movies’ of an action
and then asked them to judge same/different for a test picture.
TMS applied to PMv, IPL and STS for controls.
Results: In experiment 1, shorter RTs when TMS to PMv and IPL regardless of whether
effector in test picture was some or different as in the adapting movie.
Results: In experiment 2, shorter RTs when TMS to STS but only if same effector used;
TMS to PMV reduces RTs for both effectors (see Figure 4).
Two degrees of abstractness.
Low, Edwards, & Butterfill (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Inspiration: Action anticipation can influence reaction times.
NB: In this experiment, participants had to imitate a reach-to-grasp
movement which was modelled for them before the go-stimulus (the mug)
appeared.
WHat is measured? Movement initiation times. (NB not response times.)
Costantini et al, 2010 figure 1b
Anticipation associated with other people’s action possibilities
can also influence your movement initiation times.
Costantini et al, 2011 figures 3,4
Outcomes such as reaching for and grasping of a cup can be represented motorically.
As a body of research on mirror neurons and motor simulation more generally demonstrates,
motor representations of outcomes can generate expectations concerning another agent’s behaviour
These expectations are plausibly compared with the behavior that is actually observed.
And we conjecture that the result of this comparison modulates the strength of the motor representation of the outcome.
Within limits, this modulation will ensures that an outcome represented motorically is likely to be a goal of the observed action.
In this way, motor representations enable goal tracking.
So far we have nothing about belief-tracking. Where could that come in?
Jason’s pilot indicates that belief-tracking, which I suppose involves representing registrations, can influence behavioural expectations.
But how?
In principle, we might imagine that the belief-tracking process results in a second, independent behavioural expectation.
While we cannot rule this possibility out, it seems to add theoretical complexity.
After all, belief-tracking depend so on goal-tracking in this way: you can only track another’s mental states by tracking their actions. We therefore need the goal-tracking process to provide input to the belief-tracking process.
But if the goal-tracking process ignores the belief-tracking process, then false beliefs would cause it to make systematic errors about the goals of actions. Since these errors would feed into the belief-tracking process, it would seem that this process too should go wrong whenever there is a false belief. But then there would be no point in tracking beliefs at all.
Our proposal is therefore different: the belief-tracking process influences the process by which the behavioural expectation is generated.
The representation of registration means that behavioural expectation is generated as if things were as they are registered as being, rather than as they actually are.
Put colourfully, another’s registration can change the world as seen by your motor system.
(This might be why Katheryn has repeatedly found altercentric intereference effects of belief on motor actions.)
This picture has a radical implication about the nature of the automatic belief-tracking processes.
It implies that those belief-tracking processes must interface directly with motor processes.
This requires, in turn, that automatic belief-tracking represents objects and outcomes in the same format as the motor representations do.
Motor processes and belief-tracking must share a common representational format.
Although lots of details are not specified by the picture, its is does make readily testable predictions. For one thing, it implies that limits on what can be represented motorically are also limits on automatic belief-tracking.
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 1, part) based on Kovács et al. (2010)
Low et al. (2020, p. figure 2)
Nice replication, which is mildly interesting because we used a movie clips
with real people rather than smurfs.
Low et al. (2020, p. figure 3)
Six (2022, p. figure 11)
‘participants in the movement-restricted group were required to hold on to the elastic band
at the start of every experimental block.’
(Six, 2022, p. 98)
[Six (2022, p. 95) Experiment 1: ‘predictive gaze behaviour was modulated by the false belief state of the agent’]
So far, so good.
[In Experiment 1, we had no response to the videos required but there was a visual detection task - press a key when
one of the cups turns purple, which we expected would help to keep people attentive and ‘disguise the real purpose
of the expeirment’.]
The basic finding that false belief states modulate predictive gaze behaviour was partially replicated in Experiment 2,
(although differently from Experiment 1, ‘In the false belief condition, we saw that anticipatory looking times generally
sat around chance level.’ but this could be due to some technical difficulties with the equipment?)
[Ask Pieter: I think the attention check still involved a keypress, which the participant could do with the elastic band?]
However the motor mindreading prediction was not supported:
‘Our crucial manipulation in this experiment was the addition of a group that was motor-restricted and
therefore unable to grasp for a cup, which should in principle attenuate motor simulation and action prediction.
This, however, was not the case.’ (Six, 2022, p. 111)
[Also Six (2022, p. Experiment 3) did not find evidence that false belief states modulate predictive gaze behaviour.
I think this may be because we asked participants to predict the action on each trial
(‘Unlike previous experiments, this experiment featured a question prompt (“on which side of the screen
will the hand appear?”) after each trial upon participants were asked to respond vocally with “left” or “right”.’)
Notably, DLTS and explicit behavioural predictions were tightly correlated; this suggests to me that
asking the question may have altered which processes moved the eyes.]
Zani, Butterfill, & Low (2020)
When I chose my title, Motor Mindreading, Jason, Pieter, Gio and I in the land of milk and honey.
We couldn’t run an experiment without confirming your predictions.
Since then I think it is fair to say that
we seem to have taken a long walk in the desert.
So I cannot report that we have established the existence of motor mindreading.
Not yet.
But the desert is beautiful in its way, and so I remain hopeful that there
will be more experiments which add to the evidence we already have.
Let’s see.
Motor Mindreading?
[email protected] & [email protected]
For now my conclusion is simple.
Cecilia’s talk is about selecting the most successful of older theories about mirror neurons’ functions
and stepping back from some of the wildest ideas about their roles in our lives.
This ground clearing is important because it provides the perfect environment for
the next generation of wild conjectures about the roles of mirror neurons.
... like the idea that they can play a role in some forms of mindreading.