The current thesis explored the intentional forgetting of different types of facial expression (Angry, Neutral, Happy) within the item-method directed forgetting paradigm (Experiments 1-4). Also, as a manipulation check, Experiment 5 obtained the subjective ratings of valence and arousal for the different types of facial expression used in the previous four Experiments. In summary, a significant directed forgetting effect occurred for Neutral facial expressions; however, a significant directed forgetting effect did not consistently occur for emotional facial expressions (e.g., there was no directed forgetting effect for Angry facial expressions in Experiments 2 and 3, or Happy facial expressions in Experiment 3). These findings are discussed in terms of encoding time as well as valence and arousal, and how these two factors modulate the effect of emotional facial expression on the ability to intentionally forget.

abstract: It has been suggested that directed forgetting (DF) in the item-method paradigm results from selective rehearsal of R items and passive decay of F items. However, recent evidence suggested that the passive decay explanation is insufficient. The current experiments examined two theories of DF that assume an active forgetting process: (1) attentional inhibition and (2) tagging and selective search (TSS). Across three experiments, the central tenets of these theories were evaluated. Experiment 1 included encoding manipulations in an attempt to distinguish between these competing theories, but the results were inconclusive. Experiments 2 and 3 examined the theories separately. The results from Experiment 2 supported a representation suppression account of attentional inhibition, while the evidence from Experiment 3 suggested that TSS was not a viable mechanism for DF. Overall, the results provide additional evidence that forgetting is due to an active process, and suggest this process may act to suppress the representations of F items. / Dissertation/Thesis / Ph.D. Psychology 2011