The impact of object affordance activation level on cognitive processing of tools.

Previous studies have identified different outcomes in the cognitive processing of tools but have overlooked the role of the activation level of object affordances. To address this issue, the present study conducted four behavioral experiments. Experiment 1 employed a color judgment task under low affordance activation and revealed a significant tip-dominance effect, with faster responses in stimulus-response incompatible than compatible conditions (t (29) = 3.35, p = 0.002, d = 0.61). In Experiment 2, we increased affordance activation by using typical color but observed no significant compatibility effects (all ps > 0.05). Experiment 3 adopted a Go/NoGo paradigm and introduced semantic attributes, yielding a significant stimulus-response compatibility (SRC) effect (F (1, 27) = 9.22, p = 0.005, η²p = 0.25). Experiment 4, focusing on atypical colors, showed a reversed compatibility effect for power-grasp tools (t (29) = 3.19, p = 0.003, d = 0.58), but not for precision-grasp tools. Together, these findings indicate that (1) the activation level of object affordances modulates tool-related cognitive processing; (2) low activation leads to dominance of functional-end responses, whereas higher activation elicits SRC effects; and (3) both perceptual and semantic attributes contribute to affordance activation, with semantic effects emerging only when perceptual attributes are present.