How your eyes reveal a change of mind before you turn
Tracking gaze during virtual journeys shows that eye movements reveal hidden mental doubts and predict changes of mind before subjects alter course.
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The full story with proper science words explained.
A telltale flick of the eyes
Before a monkey switches direction in a digital world, its gaze already gives the game away.
We often alter our plans mid-stride. In this study, scientists used eye tracking decisions to see if gaze movements expose these hidden shifts in thought.
Testing movement without a map
Researchers placed both humans and monkeys into a virtual space without clear position cues. The participants performed a naturalistic navigation task, steering towards goals that appeared either together or one after the other.
During these sequential target trials, a second destination popped up while the subject was already heading towards the first. The team tracked eye movements continuously to watch how gaze shifted between the competing destinations.
Spotting doubt before the turn
The eyes revealed far more than just the final choice. Eye movements reflected an internal latent variable, which is a hidden mental estimate such as belief about position, along with the uncertainty around it.
Remarkably, gaze accuracy before the second target even appeared predicted whether a participant would stay the course or make a change of mind. If their gaze wavered early, they were far more likely to switch paths when the new option arrived.
Think of the eyes like a ship's searchlight sweep. The beam darts towards a new harbour before the captain actually turns the heavy steering wheel.
What we still don't know
A ship's searchlight is aimed on purpose, whereas these eye movements happen almost automatically. This study is an early preprint that has not yet been peer-reviewed.
The test only used a simple choice between two goals in a computer simulation, rather than real terrain with many obstacles. The exact brain circuits linking eye movements to continuously updated beliefs also remain unknown.
Science words
- Naturalistic navigation task
- A continuous movement exercise designed to simulate realistic travel towards a destination.
- Sequential target trials
- Experimental rounds where potential goals are displayed one after the other instead of all at once.
- Latent variable
- An internal, hidden mental state or estimate—such as belief or position—that cannot be directly observed.
- Change of mind
- Revising a decision or choosing a different goal while already in the middle of executing an action.
Check it yourself
This story is based on a real research paper in Preprint by Choi, Alefantis, Andreadakis et al.. We write with AI help and check it against the paper, but the original is the final word.