In sequential two-choice tasks, performance generally improves when both stimulus features and responses are repeated but deteriorates when only one repeats while the other changes (partial repetition). This interaction, commonly referred to as the stimulus-response binding effect, is attributed to the integration and retrieval of stimulus and response features into an episodic memory trace, which can interfere with current performance during partial repetition trials. An alternative explanation, the signaling account, suggests that response selection is influenced by a heuristic bias toward repetition or change, using the relationship between previous and current stimulus features as a response signal.
The present study examined whether the signaling heuristic is modulated by contextual information that, according to binding accounts, should not influence binding effects. Participants completed a sequential task where display set sizes varied within participants (Experiment 1, allowing display comparison) or between participants (Experiment 2, disallowing display comparison). Contrary to typical findings in two-choice tasks, binding effects were absent at small set sizes and only emerged at larger set sizes in Experiment 1, whereas results were consistent across set sizes in Experiment 2. These findings suggest that the signaling heuristic adapts to contextual information, incorporating environmental factors to adjust the use of stimulus information for response strategies.