绝对重要性和认知负荷影响基于事件的前瞻记忆

The Impact of Absolute Importance and Cognitive Load on Event-based Prospective Memory

采用绝对重要性的指导语来操纵前瞻记忆任务重要或者不重要,并且以Stroop任务作为进行中任务,来考察绝对重要性和认知负荷对基于事件前瞻记忆的影响。结果发现,低认知负荷条件下的前瞻记忆表现好于高认知负荷条件。低认知负荷条件下,强调重要性有利于进行中任务的完成;而在高认知负荷条件下,强调重要性则不利于进行中任务的完成。这说明,认知负荷会影响前瞻记忆的重要性效应,支持多重加工理论。

Prospective memory is to remember an intention at an appropriate moment in the future, and can be classified into event-based prospective memory(EBPM) and time-based prospective memory(TBPM). The importance of prospective memory task can be manipulated by using relative importance instructions(i.e., emphasizing that the prospective memory task is more important relative to the ongoing task) or absolute importance instructions(i.e., emphasizing that the prospective memory task itself is important). Previous studies have shown that manipulating relative importance resulted in enhanced prospective memory performance but came at costs in the ongoing task. However, the influence of manipulating absolute importance on event-based prospective memory and its processing mechanisms is still not clear. The existing studies have shown that the occurrence of an importance effect on prospective memory may be influenced by cognitive load of the ongoing task. The aim of the present study was to investigate the effects of absolute importance and the cognitive load of the ongoing task on event-based prospective memory. A group of 31 college students participated in this study with a 2(absolute importance: important vs. non-important) by 2(cognitive load: low vs. high) within-participant factorial design. We manipulated the absolute importance by instructing participants that remembering to perform the prospective memory task was very important or not important, and adopted the Stroop task as ongoing task, with color-word congruent condition as low load condition and color-word incongruent condition as high load condition. Four Chinese characters(red, yellow, blue, green) written in one of the eight colors(red, yellow, blue, green, pink, orange, cyan, emerald) were used and were presented in pseudorandom order. The Stroop task was to identify the appropriate color(red, yellow, blue, green) of the Chinese characters by pressing the correct keys on the computer keyboard as quickly as possible. The prospective memory task was to press the space key on the computer keyboard upon the presentation of one of the four specific colors(pink, orange, cyan, emerald) while performing the Stroop task. The results revealed that the reaction times(RTs) in the prospective memory task in the low load condition was faster than the high load condition. Importantly, there were interactions between absolute importance and cognitive load for both accuracies and RTs in the ongoing task. In the low load condition, the ongoing task performance with emphasizing the importance of prospective memory task was better than that in the nonimportant condition. However, in the high load condition, the ongoing task performance with emphasizing the importance of prospective memory task was poorer than that in the non-important condition. The present study suggests that cognitive load of the ongoing task modulates the effects of absolute importance on ongoing task, consistent with the multi-process theory. When the current ongoing task is of low cognitive load, emphasizing the importance of prospective memory task may boost the performance of ongoing task together. However, when the current ongoing task is of high cognitive load, emphasizing the importance of prospective memory task may occupy scarce cognitive resources and hence interfere with the performance of the ongoing task.