Concurrent schedule control of human visual target fixations.

Adult volunteers sat in a quiet lab. They watched a small screen that showed a faint target dot.

Each time the person looked at the dot, the machine paid off with a brief light flash. Three schedules ran at once: VR (look a few times), DRL (wait a bit), and FI (wait longer).

The goal was to see if simple operant rules could steer where humans point their eyes.

The schedules did control fixations. People looked when the rules said looking would pay off.

The paper never says how big the change was or how many looks happened. It only states that schedule control was clear.

Pergher et al. (2025) extends this idea. They reversed the payoff rules for whole stimulus classes and saw gaze times flip in real time. Together the two papers show that human eye movements are not just operant—they are also quick to retune when contingencies shift.

CATANIDINSMOOR (1962) is a direct predecessor. That study taught us to add a change-over delay so concurrent VI schedules stay clean. Van Hemel (1973) used the same logic but applied it to eye fixations instead of lever presses.

Catania et al. (1974) used a similar lab setup. They found that concurrent reinforcement flattened stimulus-control gradients. Van Hemel (1973) moves the focus from line tilts to target dots, yet both reveal how reinforcement reshapes what we see.

If schedules can steer something as tiny as an eye shift, they can steer bigger forms of attending. When you build visual tasks for clients—match-to-sample, joint attention, or vigilance games—think in schedules. Pair the target with a quick VR payoff for looks, add a short DRL for waiting, and sprinkle in FI for endurance. The eye-tracking work says the child’s gaze will follow the same rules Van Hemel (1973) saw in adults.