Proceedings of the Annual Meeting of the Cognitive Science Society

The attraction effect—where a decoy option increases preference for a dominating target—is a cornerstone of context-dependent choice, yet it is paradoxically fragile. Sequential accounts propose that context effects depend on which pairwise comparisons are emphasized during deliberation, but existing tests often confound comparison availability with memory/recency. We introduce a Self-directed Expanded Judgment paradigm in which participants repeatedly unblur and judge available option pairs, allowing information search to be observed and constrained. In Experiment 1, we validate the method by replicating a positive attraction effect. In Experiment 2, we causally manipulate comparison availability by disabling specific pairwise links while equalizing cumulative stimulus exposure at the decision stage (top-up control). Consistent with the preregistered hypothesis, the target's relative share (RSTew) differed reliably between conditions, with the disabled Competitor-Decoy pair producing a positive attraction effect. In exploratory analyses, the disabled Target-Decoy pair produced negative attraction (repulsion). These findings provide causal evidence that the accessibility of specific pairwise comparisons can modulate—and under some conditions reverse—context effects.