Negative affect interacts with perceptual affective biases

BackgroundAffective biases are central to mood and anxiety disorders, with individuals often interpreting ambiguous facial expressions more negatively. Adaptation paradigms - where exposure to emotional stimuli shifts perception - offer a tool to separate perceptual from decisional biases, but have not yet been used to study emotional biases in affective disorders.MethodsEighty participants completed emotion and identity discrimination tasks before and after adaptation, making binary judgments on morphed facial expressions (happy/sad) and identities (Bonny/Sheila), followed by confidence ratings (high/low). Logistic and Gaussian functions were used to model responses, with adaptation effects indexed by shifts in the point of subjective equality (PSE) and confidence.Results Adapting to happy faces produced a bias toward sad judgments of ambiguous faces, while adapting to sad faces produced the opposite effect. Similar adaptation effects were observed for identity judgments. PSE and confidence shifts were positively correlated, indicating perceptual rather than decisional bias. Crucially, a negative affect factor (derived from BDI and STAI-Y2) moderated the degree of perceptual bias towards sad expressions following happy adaptation. This effect was specific to negative perceptual shifts, and not shifts towards positive expressions or identity. ConclusionThese findings suggest that negative affect interacts with ‘low-level’ perceptual processes in affective biases. This aligns with cognitive neuropsychological models of mood disorders, which propose that antidepressants initially target early perceptual processing to reduce negative biases. By demonstrating how negative affect alters fundamental aspects of facial emotion perception, this study provides new insights into the perceptual mechanisms underpinning mood and anxiety disorders.