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What underlies Agency: Perceiving Causality

Perceiving causality means to perceive and intuitively understand a cause-effect relation from simply obersving or sensing it. Perceiving Agency can be thought of as a special case, where we do not passively observe, but actively intervene and intuitively understand the cause-effect of our own action.

But let's start with a bit more intuitive example :)

Launching Coffee Cups

Let's imagine, you sit in a café in a rather crowded city. Outside people pass by minding their daily business, some with sour Monday morning looks on their faces and medium-bad coffee in their to-go cups, some with their gaze drilled into their smartphones and their ears plugged by little white antennas connecting them to cyber space.
Suddenly you observe one of the latter species with only 3 of their 5 senses intact walking straight towards a representant of the first species standing around, looking at their watch and taking a sip of their black gold. Of course the one bumps into the other, who stumbles and even sends their coffee flying.
If you were now asked what happened you'd immediately say something that boils down to person A bumped into person B who then stumbled. You immediately understood the direction of causality and the resulting effect, that is the cause-effect relation.

What you have just observed could be called a "human launching event", leaning on the broken down visual stimuli that we usually use in the lab. These stimuli are controlled for every little aspect and thus often very simplistic, such as the ones we have used in this study:

We (that is my colleagues from Marburg) have shown these stimuli to our participants and asked them whether they perceived the event as causal or non-causal.
"Well, that's obvious", you might think. And yes it is, so we added a delay and an angle to the red disk's movement to make it wait a bit after the contact and to make it move not in a straight path.
It has already been shown that adding these implausibilities reduces the average perceived causality, so people report events with a big delay less often as causal. However, even if there is a very big delay or a very big angle, some trials are still rated as causal, i.e. causality does not vanish completely.
There are many reasons why the causal impression of such a simple event never fully disappears. For example I believe human imagination could play a role: Maybe the participants just imagine these dots to be two people in a crowded street bumping into each other. And suddenly, in this context, these doesn't need to be a straight path to make the event causally plausible.

Dependent Rouelette Gambling

The aspect we investaged in our study though, was more tangible: We wondered whether a causality judgement a participant made in one trial had an effect on their next answer. The simple answer to this question is Yes. Though it would hardly be science, if we'd stop here and didn't wonder about the how.

Now, let me motivate the how with another little story.

My friends and I have somewhat built up a tradition over the last years. Before christmas, we all dress up in the fanciest suits we can find in our cupboards, attach a vintage bow tie, have a Glühwein on the christmas market and head for the the casino. Some of us winning, most of us loosing, but all feeling fancy and having fun.
What caught my eye on one of those evenings was the betting behaviour at the Roulette tables. Many bet on either black or red (both having on average a 48.6 % chance). Sometimes, a table spat out the same colour again and again, all black for the last 10, 15, 20 draws. Such is chance. Funnily however, if such sequences occur, more and more people are drawn to the opposite color. They are clearly influenced by the past outcomes of the gamble although there is no information in it - unless some trick is at work. Such is human nature.

Causality an Schizophrenia

So far I tried to give an intuition about the how (methods) and the what (research question). Let me also motivate the the who (research population).
Maybe the question how previous decisions influence our current choices is already interesting for the general population. But my colleagues in Marburg, however, are focussed on a special population, patients with Schizophrenia Spectrum Disorder (SSD). People with SSD can have problems with perceiving cause-effect relations. For example, not registering the relation between an intention and a movement can lead to the delusion that their hand moved on their own.

Putting it all together... and giving some answers

Now, that was a long way to simply explain the research question:

"What is the influence of past events and decisions on perceived causality judgements in Schizophrenia Spectrum Disorder?"

Let's be quicker with the results.

  1. Yes, past decisions have a direct influence on current causality judgements. We generally tend to stick to the same answer we gave previously, that is, if we said "causal" in the previous trial, we are now more likely to also say "causal", independent of what is actually going on in the event. Same the other way around, for saying "non causal". Interestingly, this bias was on average not much different between our two groups of healthy people and people with SSD.

  2. Of course, a causal judgement is also influenced by the delay and angle of the current event. Here it was interesting, that our healthy control group put more importance on the delay and the group with SSD more importance on the angle. What do I mean with importance? A look at Figure 2 can help. SSDs, for example, reported on average more causality for a direct path than healthy control, but less causality for a path with 60 ° angle of egress. They were more influenced by the spatial information (angle) than their healthy control counterparts.

Now, it would be a bit boring if that was all we found though.

  1. It gets more interesting when we look at how this choice-bias interacts with the angle and delay of the current event. Long story short: If what we currently observe is ambuguous, we just use our previous choice as a fall-back. Have a look at Figure 3!
  2. And finally, we took a look at how these influences of angle, delay and past choices develop over time. Leaning on the story above you can ask, how does your betting behaviour change over the evening? At least for our launching events, the bias of the previous choice went down for healthy controls, but increased for our SSD population! We argued that potentially, HCs learnt the scope of the experiment (range of angles and delays that were possible) over time and were better able to place a single event into the context of what they learnt. SSDs on the other hand, couldn't.

You can find more detailed answers (and nice figures) in the paper we published on this in 2025:
"Choice- and trial-history effects on causality perception in Schizophrenia Spectrum Disorder"

Too long, didn't read

tl;dr
We use Michotte Launching events to study the judgements of perceptual causality in healthy controls and schizophrenic patients.
I used a fancy linear regression (GLMM) for looking at the influence of the last launching event and the choice that was made on the current choice.
The last choice indeed influences our perception of causality, both, in an easy to grasp direct way and by modulating the influence of other factors.

Acknowledgements

This research was funded by the project The Adaptive Mind - now also a "Cluster of Excellence".