Characterizing individual differences in selection history bias manifested in goal-directed reaching movements.

Everyday interactions with a complex environment often demand selecting a single target among multiple distractors. A recent framework of attentional control suggests that object selection is influenced not only by perceptual salience and current goals but also by selection history. Here, we examine how this interplay between target and distractor history manifests in individual differences in target selection for goal-directed reaching movements. We employ a priming-of-popout (PoP) paradigm combined with continuous tracking of reaching movements. Participants reach for an odd-colored target among homogeneous distractors while we systematically manipulate the sequence of target and distractor colors from one trial to the next. We record behavioral data such as reach trajectory, initiation latency, and movement time, and calculate attraction scores using the single target reach trajectory as the baseline to evaluate performance across six conditions. For each participant, we determine their maximum attraction score and its timing for each condition. Subsequently, using k-means clustering and t-SNE analysis identifies four distinct clusters as subgroups, indicating different strategies in attentional and action selection with varying degrees of influence from previous target versus distractor feature repetition and their distinct contributions to PoP. Our findings underscore that previous selection history triggers a dynamic interaction between target facilitation and distractor inhibition, resulting in individual differences in target selection strategies for goal-directed actions.