Serial dependence in goal-directed interceptive hand movements

Serial dependence-the influence of recent sensory history on current perception and action-has been studied extensively in perception but less in sensorimotor control. We investigated how sequential effects influence manual interception, where responses depend on continuous real-time information about moving targets. Participants performed an interception task where each trial consisted of two sequentially presented targets. The first target, the prior, moved either leftwards or rightwards at a velocity of 5 or 15 cm/s. The second target, the probe, always moved at 10 cm/s, either in the same or in the opposite direction as the prior. To dissociate the role of active motor engagement with the prior from its purely perceptual influence on probe interception, participants completed two conditions: intercepting both prior and probe targets, and only observing the prior and intercepting the probe.

Interception errors exhibited distinct, context-dependent effects: When the prior was intercepted, there was an attractive bias when the prior and probe moved in the same direction, and a repulsive bias when they moved in opposite directions. When the prior was not intercepted, the interception of the probes was not influenced. The temporal evolution of hand velocities revealed that there was an initial attractive sensory serial dependence effect that affected hand movements, which was also reflected in eye movement behavior. The priors' influence diminished over time as new sensory information accumulated for online control of interception.

Our study provides novel insights into how sensory history and motor engagement interact to shape continuous sensorimotor control.