内隐重复效应影响外显工作记忆的年龄差异

采用延迟样本匹配任务并控制被试对部分项目的有意识学习经验, 当前研究考察了老年被试与青年被试在追逐靶、排除分心物的过程中, 重复启动效应如何受到项目外显学习经验的影响。老年被试和青年被试首先学习一些物体图片, 这些熟悉的图片与一些新图片作为之后工作记忆任务的靶或分心物。结果发现, 老年被试与青年被试在追逐靶和排除分心物的过程中均受到项目之前学习经验的影响。无论是老年被试还是青年被试, 对靶的反应时均快于对分心物的反应时, 对外显学习过的靶(即熟悉靶)的反应时快于对未学习过的靶(即新靶)的反应时, 而拒绝熟悉的分心物需要的时间长于拒绝新分心物的时间。其次, 老年被试与青年被试均表现出对靶的重复效应, 即当靶(无论是熟悉的还是新的)在任务中重复出现时, 对其的反应时加快; 然而, 对分心物的重复效应显著减小。随着项目多次重复, 重复效应整体上减小, 但该效应的变化受到项目属性(靶或分心物)以及项目之前学习经验的影响。重要的是, 当熟悉的分心物反复出现时, 老年被试不但没有出现重复效应, 反而在拒绝该熟悉分心物上表现出困难, 反应时显著延长, 而在青年被试上没有该表现。这些结果说明, 老年被试的工作记忆任务成绩容易受到内隐熟悉性的干扰, 重复出现的干扰项产生的熟悉性使得老年被试难以拒绝。

Age Differences in the Repetition Effect for Studied or New Objects

The current study investigated the age differences in repetition priming of studied or new objects in a delayed-matching-to-sample task involving common objects. Prior to matching task, older or young participants intentionally studied a set of object pictures. For the matching task, a trial began with the presentation of two sample pictures (both were studied objects or both were new objects), then followed by twelve successive test pictures. The test pictures were classified into four types: studied match, new match, studied non-match, new non-match. Each types of test picture were repeated for three to four times within each trial. Participants were instructed to judge whether each test picture match one of the sample pictures or not as quickly and as accurately as possible. The results showed that older adults were generally slower than young adults in response, and both older and young participants respond faster to matches than to non-matches. RTs to studied matches were faster than to new matches, but RTs to studied non-matches were slower than to new non-matches for both older and young adults. Moreover, both older and young adults showed repetition effect for matches, with reduced repetition effect for non-matches. Repetition effect was reduced over times, and was differentiated between older and young participants. Importantly, while young adults showed no repetition effect for studied non-matches, older adults were significantly longer in response to repeatedly presented studied non-matches. These results demonstrated that implicit repetition effects for objects in older and young adults were affected by previous experiences with these objects. Repeatedly presented non-matches induced higher familiarity and caused difficulty for older adults in rejecting them, but this familiarity did not affect young adults.