Negative affect interacts with perceptual affective biases

Affective 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, provide a tool to separate perceptual from decisional biases, but have not been used to study emotional biases relevant to affective disorders.

To determine whether affective biases in facial emotion perception arise from perceptual or decisional processes, and to examine how these biases are modulated by individual differences in negative affect.

Eighty participants completed emotion and identity discrimination tasks before and after adaptation. Participants made binary judgements of morphed facial expressions (happy/sad) and identities (Bonny/Sheila), followed by confidence ratings. Logistic and Gaussian functions were used to estimate adaptation effects from shifts in the point of subjective equality (PSE) and peak uncertainty.

Adaptation produced repulsive aftereffects: exposure to happy faces biased perception towards sadness, and vice versa, with analogous effects for identity. Correlated shifts in PSE and uncertainty indicated a perceptual rather than decisional origin. Negative affect (derived from Beck Depression Inventory and State Trait Anxiety Inventory-trait questionnaires) moderated this relationship, such that individuals higher in negative affect showed stronger perceptual biases towards sadness.

Findings suggest that negative affect modulates low-level perceptual encoding of emotional expressions. This supports cognitive neuropsychological models positing that antidepressants first target early perceptual biases and highlight perceptual encoding as a potential mechanism underlying affective biases in mood and anxiety disorders.