Article
Non-uniform temporal weighting of intensity in audition and vision: The signature of an evidence integration process? (en)
* Presenting author
Abstract:
Loudness judgments for sounds varying in intensity across time depend more strongly on early temporal portions of the stimulus than on later parts (primacy effect). A potential explanation for this pattern of temporal weights (TWs) arises in the context of evidence-integration approaches, which assume that participants accumulate evidence across the duration of the stimulus until a decision threshold is reached. Because evidence integration represents a supramodal decision mechanism, an interesting prediction is that TWs for different sensory channels should be similar at the individual level. To address this hypothesis, Experiment 1 compared TWs for loudness and brightness judgments within the same participants. The observed average temporal weighting profiles differed substantially between the two modalities. In Experiment 2, we investigated the additional contribution of modality-specific sensory and attentional processes to the observed differences between TWs by measuring intensity resolution at different temporal positions in the auditory and visual stimuli. We observed a significantly different dependence of sensitivity on temporal position in the two modalities, but these sensitivity differences accounted only partially for the differences between TWs observed in Experiment 1. The results suggest that the TWs for loudness and brightness judgments cannot be caused exclusively by a supramodal evidence-integration process.