Dissociating Sensory and Decision Processes in Tasting: Intensity Affects Sensitivity, while Expectancies and Feedback Interact, Affecting Decision Criteria

The aim of this study was to examine the influence of feedback on the dynamics of sensory and decision processes in a tasting task involving mixtures of salty and sour basic tastes. The Double Dissociation Additive Test within the Signal Detection Theory framework was applied to assess the effects of manipulating intensity, signal-noise base rates, and feedback on sensitivity and decision-making processes. Participants’ discrimination improved as salt concentration increased, regardless of induced bias or feedback presence; however, feedback led to a general increase in sensitivity. Both signal-noise stimulus base rates and feedback influenced the decision-making process. When feedback was present, detection judgments aligned more closely with actual signal-noise stimulus base rates. However, in the absence of feedback, the relationship between base rates and response bias reversed. Implications for research in sensory evaluation and perceptual learning are discussed.