| dc.description.abstract | Abstract
Two electrophysiological studies and a series of behavioral experiments were conducted to investigate the cognitive/neural mechanisms underlying the item-method directed forgetting effect. For the two electrophysiological studies, brain waves were recorded when subjects engaged in the simple old/new recognition task and the directed-forgetting recognition task respectively. In the study phase of the item-method directed forgetting task, each study item was followed by either a “R” or a “F” cue, which instructed the subject to remember or to forget the preceding item respectively. In the following test phase, subjects were presented with all the study items intermixed with unstudied new items. Subjects were instructed to identify all study items, regardless of whether these items had been instructed to be remembered or to be forgotten in the earlier study phase.
For both the simple recognition task and the directed forgetting task, ERPs were recorded in the study and test phases. The ERPs recorded during the test phase were sorted and compared according to the response categories the eliciting stimuli belong to (i.e., hit, miss, false alarms, and correct rejections in the simple recognition task; hit and miss to to-be-remembered and to-be-forgotten items, false alarm, and correct rejections in the directed forgetting task). For the ERPs recorded at study, these waveforms were also categorized according to the subsequent response the study items elicited in the subsequent test phase (i.e., subsequently remembered and forgotten items).
Following these two electrophysiological studies, a series of behavioral studies were conducted to clarify the properties of the cognitive processes involved in the item-method directed forgetting effect. These behavioral studies were (a) pre-cued item-method directed forgetting task, in which the remember and forget cues were presented before, rather than after, the presentation of the study items, (b) item-method directed forgetting task with source judgments, in which subjects were required to identify whether a recognized item had been followed by a R or F cue in the earlier study phase; (c) item-method directed forgetting with exclusion tasks, in which the target items could be to-be-remembered or to-be-forgotten items. It is expected that these ERP and behavioral results would advance our understanding of how people remember and forget the episodes they have experienced. | en_US |