Contributed Talk Sessions | Poster Sessions | All Posters | Search Papers

Poster Session A: Tuesday, August 12, 1:30 – 4:30 pm, de Brug & E‑Hall

Response Strategy Reverses Serial Dependence: From Attraction to Repulsion

Aviel Sulem¹, Merav Ahissar; ¹Hebrew University of Jerusalem

Presenter: Aviel Sulem

Perceptual decisions are substantially biased by recent stimuli—a phenomenon termed serial dependence. Yet, what determines whether this bias is attractive (toward the previous stimulus) or repulsive (away from it) remains unclear. Previous studies focused on task structure and did not consider how individuals’ response strategies might influence bias. Here, we show that response speed—whether natural or instructed—critically shapes the direction of serial dependence. In a two-face discrimination task using a uniform morph continuum between two female identities, slower responders showed attraction, while faster responders showed repulsion. To test causality, we repeated the experiment and manipulated strategy within subjects by instructing participants to prioritize either speed or accuracy. The more participants sped up, the more repulsive their bias became. Repulsion in fast responses appeared consistent with a shift toward long-term representations—specifically, stronger attraction toward the nearest face prototype and reduced influence of the previous stimulus. These findings demonstrate that response strategy modulates serial dependence, likely by altering the balance between short- and long-term history.

Topic Area: Predictive Processing & Cognitive Control

Extended Abstract: Full Text PDF