When neutral is not neutral: Neurophysiological evidence for reduced discrimination between aversive and non-aversive information in generalized anxiety disorder

Generalized anxiety disorder (GAD) is characterized by a range of cognitive and affective disruptions, such as pathological worry. There is debate, however, about whether such disruptions are specifically linked to heightened responses to aversive stimuli, or due to overgeneralized threat monitoring leading to deficits in the ability to discriminate between aversive and non-aversive affective information. The present study capitalized on the temporal and functional specificity of scalp-recorded event-related potentials (ERPs) to examine this question by exploring two targeted neurocognitive responses in a group of adults diagnosed with GAD: (1) visual processing of angry (aversive) versus neutral (non-aversive) faces; and (2) response monitoring of incorrect (aversive) versus correct (non-aversive) responses. Electroencephalography was recorded while 15 adults with GAD and 15 age-matched controls viewed angry and neutral faces prior to individual trials of a flanker task. ERPs to faces were the P1, reflecting attention allocation, the early posterior negativity (EPN), reflecting early affective discrimination, and the N170, reflecting face-sensitive visual discrimination. The error-related negativity (ERN) and positivity (Pe) were generated to incorrect and correct responses. Results showed reduced discrimination between aversive and non-aversive faces and responses in the GAD relative to the control group during visual discrimination (N170) and later-emerging error monitoring (Pe). These effects were driven by exaggerated processing of non-aversive faces and responses, suggesting over-generalized threat monitoring. Implications for cognitive-affective models of GAD are discussed.