Motor skill learning in the middle-aged: limited development of motor chunks and explicit sequence knowledge

The present study examined whether middle-aged participants, like young adults, learn movement patterns by preparing and executing integrated sequence representations (i.e., motor chunks) that eliminate the need for external guidance of individual movements. Twenty-four middle-aged participants (aged 55–62) practiced two fixed key press sequences, one including three and one including six key presses in the discrete sequence production task. Their performance was compared with that of 24 young adults (aged 18–28). In the middle-aged participants motor chunks as well as explicit sequence knowledge appeared to be less developed than in the young adults. This held especially with respect to the unstructured 6-key sequences in which most middle-aged did not develop independence of the key-specific stimuli and learning seems to have been based on associative learning. These results are in line with the notion that sequence learning involves several mechanisms and that aging affects the relative contribution of these mechanisms

The Mystery Man Can Increase the Reliability of Eyewitness Identifications for Older Adult Witnesses

Some groups of eyewitnesses, such as older adults and children, are less likely to correctly reject a target-absent (TA) line-up, as compared to younger adults. Previous research reports that using a silhouette in a video line-up called the ‘mystery man’ could increase correct rejections for TA lineups for child eyewitnesses, without reducing correct identifications for target-present (TP) line-ups (Havard and Memon in Appl Cogn Psychol 27:50–59, 2013). The current study, using older and younger adults, investigated whether using the mystery man would also increase the identification accuracy for older adults, without impairing younger adults’ identification accuracy. The results found that older adults in the ‘mystery man’ condition rejected TA line-ups significantly more often than those in the control condition (52 vs. 24 %), with no significant effect upon the TP line-ups. For the younger adults, the mystery man had no influence on identification responses for the TA or TP line-ups. Our findings suggest the mystery man technique may be beneficial for older adults, without detrimentally affecting the accuracy for younger adults, and thus could increase the reliability of eyewitness evidence, where video line-ups are employed

Not all identification tasks are born equal: testing the involvement of production processes in perceptual identification and lexical decision

The distinction between identification and production processes suggests that implicit memory should require more attention resources when there is a competition between alternative solutions during the test phase. The present two experiments assessed this hypothesis by examining the effects of divided attention (DA) at encoding on the high- and low-response-competition versions of perceptual identification (Experiment 1) and lexical decision (Experiment 2). In both experiments, words presented in the high-response-competition condition had many orthographic neighbours and at least one higher-frequency neighbour, whereas words presented in the low-response-competition condition had few orthographic neighbours and no higher-frequency neighbour. Consistent with the predictions of the identification/production distinction, Experiment 1 showed that DA reduced repetition priming in the high-, but not in the low-response-competition version of perceptual identification; in contrast, DA had comparable effects in the two versions of lexical decision (Experiments 2). These findings provide the first experimental evidence in support of the hypothesis that perceptual identification, a task nominally based on identification processes, might involve a substantive production componen