前瞻记忆需要经过策略加工:来自眼动的证据

Prospective Memory Needs Strategic Control Processing:Evidence from Eye Movements

基于视觉搜索范式,采用多目标刺激呈现的眼动测量方法探索事件性前瞻记忆的加工过程。行为结果显示,对靶目标以及干扰目标的击中率比前瞻记忆目标的击中率均更高,只有前瞻线索和干扰目标比只有靶目标的反应时更长。眼动结果显示,第一注视时间和总注视时间从干扰目标、靶目标到前瞻目标逐渐增长,在前瞻漏报中存在注视到前瞻线索的可能性,搜索序列中靶目标的存在会干扰对前瞻线索的注意。行为和眼动的结果表明,前瞻线索是否被注视到并不会决定前瞻记忆是否会成功,对于意向的实现需要目标检查或者预备注意加工过程,支持策略控制理论。

Prospective memory（PM） is the memory for actions to be performed in the future.Laboratory paradigms designed to examine the factors underlying successful prospective memory have typically utilized single element displays;however,such paradigms can＇t reflect the real rich environment in which the realization of intentions is embedded.Besides,previous experiments using a limited set of behavioral measures（i.e.accuracy and response time） can not further explore the inner processing mechanisms underlying event-based PM.The current study sought to address this issue by embedding a prospective memory task in a visual search task in which multi-objects would be presented in the display.As a complement to commonly used measures of response time and accuracy,this study examined various indices of eye movement behavior which provided insight into the eye processing and allowed us to observe which factors mainly contributed to the failures of prospective memory—either the failure to focally attend to the prospective cues or the failure to engage strategic process that facilitate the realization of delayed intentions. 18 undergraduates（8 women,10 men） averagely aged 22.25 years participated as paid volunteers.All participants were healthy,right-handed and had normal or corrected to normal vision.In each trial,individuals were presented with a single letter to encode which served as the target in the trial.The target disappeared after it was encoded and a display of 6 horizontally aligned letters appeared.The ongoing task for participants was to determine whether the target was presented in the display,and when participants saw D or M in the search display,they should press another specific key as the prospective task.There are four conditions in the displays： targets only,prospective cues only,target plus prospective cue,distractors（stimuli that were neither targets nor prospective cues）.The quantity of targets and prospective cues were counterbalanced between different conditions.Participants＇ eye movements were tracked with German SMI iView X-RED Eye Tracking System.Responses were collected using a 4-button response pad. The response accuracy data revealed that the ongoing task hits were more frequent than prospective hits,and the response time for prospective cues only as well as distractors was longer than that for targets only.The eye tracking data revealed that there were no differences among all conditions in the quantity of fixations.Both first and total fixation durations increased from distractors to targets to prospective cues.In the failures of prospective memory,the possibility of fixations on the prospective cues largely existed,and the presence of a target in the display served to disrupt the attention to prospective cues.Moreover,individuals tended to look longer at the stimulus which was associated with the response to be made.These findings suggested that the possibility of fixating the prospective cues may not necessarily contribute to the success in prospective memory,and the realization of the intentions need checking and preparatory attentional process for prospective cues,supporting strategic control processing.