Self-referential processing and emotion context insensitivity in major depressive disorder.

We examined whether differential self-perception influences the salience of emotional stimuli in depressive disorders, using a perceptual matching task in which geometric shapes were arbitrarily assigned to the self and an unknown other. Participants associated shapes with personal labels (e.g. "self" or "other"). Each geometric shape additionally contained a happy, sad or neutral line drawing of a face. Participants then judged whether shape-label pairs were as originally shown or re-paired, whilst facial emotion was task-irrelevant. The results showed biased responses to self-relevant stimuli compared to other-relevant stimuli, regardless of facial emotion, for both control and depressed participants. This was reflected in sensitivity (d') and drift rate (v) measures, suggesting that self-bias and a bias towards emotion may reflect different underlying processes. We further computed bias scores by subtracting the "neutral" value of each measure (acting as baseline) from the "happy" and "sad" values of each measure, indexing an "emotional bias" (EB) score for "self" and "other" separately. Compared to control participants, depressed participants exhibited reduced "happy" and "sad" emotional biases, regardless of the self-relevance of stimuli. This finding indicates that depressed participants may exhibit generalised Emotion Context Insensitivity (ECI), characterised by hyopoattention to both positive and negative information, at short stimulus presentations. The implications of this are discussed.