Eye movements along the establishment of functional stimuli classes
Eye gaze flips with contingency reversals, giving an instant window on stimulus-class control.
01Research in Context
What this study did
Pergher et al. (2025) watched adults’ eyes while they learned simple discrimination tasks.
The team reversed the rules so the old S+ became S– and vice-versa.
Eye-tracking cameras measured how long each picture held the viewer’s gaze.
What they found
When contingencies flipped, gaze times flipped too—sometimes in under a minute.
A few adults kept staring longer at the new S–, a brief “error” pattern.
Reversing one picture quickly changed looking time for every member of its class.
How this fits with other research
Van Hemel (1973) first showed that VR, DRL, and FI schedules can steer human eye fixations; Pergher adds equivalence-class reversals to that toolbox.
Beurms et al. (2017) proved adults form symmetry relations without extra timing cues; the new data reveal those relations can be undone just as fast.
Duker et al. (1991) built contextual control of equivalence with cross-modal transfer; Pergher’s eye data expose the moment-to-moment dynamics behind such control.
Bloomfield (1967) saw pigeons produce contrast when reinforcement shifts; humans now show a parallel, gaze-based contrast when stimulus values reverse.
Why it matters
You can see stimulus-class control change in real time by watching where clients look. If a learner keeps staring at the wrong card after a reversal, a quick prompt or extra trial may fix the class before errors spread. Eye-tracking gives you a non-invasive probe of emergent relations—no test blocks needed.
Get CEUs on This Topic — Free
The ABA Clubhouse has 60+ on-demand CEUs including ethics, supervision, and clinical topics like this one. Plus a new live CEU every Wednesday.
Watch your learner’s eyes during a reversal trial—long looks at the new S– signal the class hasn’t flipped yet, so insert extra S+ trials.
02At a glance
03Original abstract
The present study analyzed the eye movement patterns of five typically developed adults who were exposed to a series of simple discrimination training tasks with reversals in the contingencies of reinforcement that led to the formation of functional stimulus classes. Two studies were planned. In Study 1, two visual stimuli were used to carry out one training phase and three consecutive reversals. In Study 2, the phases were repeated but four‐stimuli functional classes were established. In the second study, the selective observing responses to stimuli of functional classes following the reversal of the first stimulus were analyzed. The results showed shifts in the duration of observing responses as the discriminative functions of the stimuli were established and reversed. Unlike the existing literature, our study reveals that some participants maintain longer observing responses to S– than to S+. Moreover, following the reversal of the first stimulus, observing responses to all other stimuli of the same functional class change immediately and accordingly. These findings deepen our understanding of discriminative stimulus control and shed light on the role of observing responses to stimuli composing functional classes.
Journal of the Experimental Analysis of Behavior, 2025 · doi:10.1002/jeab.70016