Incidental information processing: effects of mood, sex and caffeine

This experiment assessed the effects of various parameters on incidental information processing. Participants from a nonclinical population were asked to fill out mood and personality questionnaires before completing a simple explicit and implicit memory task. It was predicted that participants with more depressive symptoms would show lower implicit memory scores. A number of sex differences were revealed: data from male participants supported the prediction; however, female participants showed a negative correlation between increasing depressive mood symptoms and implicit memory; sex differences were also present along other cognitive dimensions. Socioeconomic effects and hemispheric biases were factors considered as possible explanations for these sex differences; hemispheric bias could have resulted in differential female/male strategies being used; these may have been responsible for the consistently higher female scores found throughout the experiment. It is also suggested that implicit memory might have a separate store; this may be influenced by the default/habitual preference for a particular processing strategy (unique to the individual participant and/or the presence of depressive symptoms).