Complexity Can Facilitate Visual and Auditory Perception

Visual and auditory inputs vary in complexity. For example, driving in a city versus the country or listening to the radio versus not are experiences that differ in complexity. How does such complexity impact perception? One possibility is that complex stimuli demand resources that exceed attentional or working memory capacities, reducing sensitivity to perceptual changes. Alternatively, complexity may allow for richer and more distinctive representations, increasing such sensitivity. We performed five experiments to test the nature of the relationship between complexity and perceptual sensitivity during movie clip viewing. Experiment 1 revealed higher sensitivity to global changes in audio or video streams for clips with greater complexity, defined both subjectively (judgments by independent coders) and objectively (information-theoretic redundancy). Experiment 2 replicated this finding but found no evidence that it resulted from complexity drawing attention. Experiment 3 provided a boundary condition by showing that change detection was unaffected by complexity when the changes were superimposed on, rather than dispersed throughout, the clips. Experiment 4 suggested that the effect of complexity, at least when defined objectively, was present without the working memory demands of the preceding experiments. Experiment 5 suggested that complexity led to richer representations of the clips, as reflected in enhanced long-term memory. Collectively, these findings show that. despite increasing informational load, complexity can serve to ground and facilitate perceptual sensitivity.