Adapting effects of emotional expression in anxiety: evidence for an enhanced Late Positive Potential.

An adaptation paradigm was used to investigate the influence of a previously experienced visual context on the interpretation of ambiguous emotional expressions. Affective classification of fear-neutral ambiguous expressions was performed following repeated exposure to either fearful or neutral faces. There was a shift in the behavioral classification of morphs toward "fear" following adaptation to neutral compared to adaptation to fear with a nonsignificant trend toward the high-anxiety group compared to the low being more influenced by the context. The event-related potential (ERP) data revealed a more pronounced late positive potential (LPP), beginning at ~400 ms poststimulus onset, in the high but not the low-anxiety group following adaptation to neutral compared to fear. In addition, as the size of the behavioral adaptation increased, there was a linear increase in the magnitude of the late-LPP. However, context-sensitivity effects are not restricted to trait anxiety, with similar effects observed with state anxiety and depression. These data support the proposal that negative moods are associated with increased sensitivity to visual contextual influences from top-down elaborative modulations, as reflected in an enhanced LPP deflection.