Abstract

The present study was to investigate the effects of anxiety and depression on implicit and explicit memory performance. Anxious, depressed, and control subjects were presented with affectively valenced words and asked to perform a self-referent encoding task. Each subject then was assessed with both perceptual identification and free recall task which are implicit and explicit test respectively. The results that are obtained are as follows; First, anxious subjects showed significantly higher priming on anxiety-related words than depressed and neutral words in perceptual identification task, but they showed significantly lower recall on anxiety-related words in free recall test. This suggests that mood-congruent implicit memory bias may be primarily associated with anxiety. However, anxious subjects showed significantly lower baseline performance for anxiety-related words. Second, depressed subjects showed an equivalent degree of priming across the word types in perceptual identification task, but they showed significantly higher recall on depressive words in free recall task. This suggests that mood-congruent explicit memory bias may be primarily associated with depression. Third, mood-congruent memory biases in anxiety and depression are characterized by a different cognitive processing operations; that is, mood-congruent memories in anxious subjects can be easily activated whereas mood-congruent memories in depressed subjects can be easily retrieved. This apparent distinction between implicit and explicit memory is emphasized by the lack of any correlation between measures of mood-congruent memory bias derived from priming and recall scores. Therefore, there is dissociation between implicit and explicit memory performance. In conclusion, the present study showed that mood-congruent implicit and explicit memory biases are essentially independent of one another, and mood-congruent implicit memory bias had more to do with anxiety, whereas mood-congruent explicit memory bias had more to do with depression.