Summary: A new study demonstrated that eye movements can serve as a powerful tool for detecting memory, even when people report not remembering. In experiments, participants rewatched animation clips with surprising events, and their gaze naturally shifted toward the spot of the surprise, indicating stored memory.
This method was often more accurate than verbal reports, proving that people sometimes remember more than they can say. The findings open new possibilities for measuring memory in infants, non-verbal patients, and individuals with neurological conditions.
Key Facts
- Memory Without Words: Eye movements reveal hidden memories even when people deny remembering.
- Study Evidence: Gaze predicted surprise events in videos, outperforming verbal recall.
- Clinical Potential: Could help assess memory in infants, Alzheimer’s patients, and brain injury cases.
Source: Tel Aviv University
Researchers from Tel Aviv University and the Tel Aviv Sourasky Medical Center (“Ichilov”), have measured subjects’ memory without asking whether they remembered something or not – just by tracking their eye movements as they watched animation videos.
The study demonstrated that people actually remember more than they report. Moreover, this method can be used to measure memory in subjects who cannot speak—such as infants, patients with brain injuries, or even animals.
The groundbreaking study was led by Dr. Flavio Jean Schmidig, Daniel Yamin, Dr. Omer Sharon, and Prof. Yuval Nir from the Sagol School of Neuroscience, the Gray Faculty of Medical and Health Sciences, and the Fleischman Faculty of Engineering at Tel Aviv University, as well as the Sagol Brain Institute the Tel Aviv Sourasky Medical Center (“Ichilov”).
The paper was published in Communications Psychology.
“Gaze Memory” Illustration by Ana Yael
“Memory is usually tested through direct questioning, with subjects verbally reporting whether they remember a certain event,” explains Dr. Flavio Schmidig, currently completing his postdoctoral research in Prof. Yuval Nir’s lab at TAU.
“For example, a subject might be shown a picture and asked if they remember having seen it before. However, this type of testing cannot be performed on animals, infants, patients with advanced Alzheimer’s, or people with head injuries who cannot speak. In this study we wanted to test memory in a more natural way, without asking people to remember.”
In the study, 145 healthy subjects watched specially created animation videos that included a surprising event – such as a mouse suddenly jumping out of the corner of the frame.
Tracking the subjects’ eye movements through two separate viewings of the same films, the researchers found that during the second viewing subjects shifted their gaze toward the area where the surprising event was about to occur.
A comparison of eye movement data with verbal memory reports indicated that the gaze direction was in fact a more accurate measure: in some cases, subjects said they did not remember the mouse, yet their gaze indicated that they did.
“The study proves that tracking eye movements can be an excellent alternative to verbal questions such as ‘Do you remember this?’,” says Daniel Yamin.
“In a series of experiments, we demonstrated that gaze direction is a very sensitive gage of memory. Even when subjects said they didn’t remember, their gaze direction showed they did. This means that sometimes people remember, but can’t say that they remember.
“By using AI machine learning techniques, it is possible to infer automatically, from just a few seconds of eye tracking, whether someone has seen a video before and formed a memory of it.”
“When I ask you if you remember,” adds Dr. Sharon, “you might give any of several answers: yes, no, not sure, etc. But when you look to the left of the frame due to a vague memory that something is about to happen there, finer nuances can be discerned. Now we have a tool for testing to what extent memory is present. Our new method is also more natural than traditional memory tests.”
“The results of this study are especially relevant when verbal reports on memory cannot be obtained,” adds Prof. Yuval Nir, the study’s supervisor.
“We believe that in the future this new method may be used for measuring memory functions in infants, Alzheimer’s patients, and people with brain injury whose speech ability has been impaired.
“Gaze direction can be simply detected by the camera of a laptop or smartphone as the subject views a video – with no need for large, sophisticated equipment. The method has the potential for identifying memories even in situations that have so far been out of reach for us as scientists and clinicians.”
About this memory and eye tracking research news
Author: Noga Shahar
Source: Tel Aviv University
Contact: Noga Shahar – Tel Aviv University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Anticipatory eye gaze as a marker of memory” by Flavio Jean Schmidig et al. Communications Psychology
Abstract
Anticipatory eye gaze as a marker of memory
Human memory is typically studied by direct questioning, and the recollection of events is investigated through verbal reports. Thus, current research confounds memory per-se with its report. Critically, the ability to investigate memory retrieval in populations with deficient verbal ability is limited.
Here, using the MEGA (Memory Episode Gaze Anticipation) paradigm, we show that monitoring anticipatory gaze using eye tracking can quantify memory retrieval without verbal report.
Upon repeated viewing of movie clips, eye gaze patterns anticipating salient events can quantify their memory traces seconds before these events appear on the screen.
A series of five experiments with a total of 145 participants using either tailor-made animations or naturalistic movies consistently reveal that accumulated gaze proximity to the event can index memory.
Machine learning-based classification can identify whether a given viewing is associated with memory for the event based on single-trial data of gaze features.
Detailed comparison to verbal reports establishes that anticipatory gaze marks recollection of associative memory about the event, whereas pupil dilation captures familiarity.
Finally, anticipatory gaze reveals beneficial effects of sleep on memory retrieval without verbal report, illustrating its broad applicability across cognitive research and clinical domains.
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