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The auditory system allows us to monitor background environmental sound patterns and recognize deviations that may indicate opportunities or threats. The mismatch negativity and P3a potentials have generators in the auditory and inferior frontal cortex and index expected sound patterns (standards) and any aberrations (deviants). The mismatch negativity and P3a waveforms show increased positivity for consecutive standards and deviants preceded by more standards. We hypothesized attenuated repetition effects in older participants, potentially because of differences in prefrontal functions. Young (23 ± 5 years) and older (75 ± 5 years) adults were tested in 2 oddball paradigms with pitch or location deviants. Significant repetition effects were observed in the young standard and deviant waveforms at multiple time windows. Except the earliest time window (30-100 ms), repetition effects were absent in the older group. Repetition effects were significant at frontal but not temporal lobe sites and did not differ among pitch and location deviants. However, P3a repetition was evident in both ages. Findings suggest age differences in the dynamic updating of sensory memory for background sound patterns., (Published by Elsevier Inc.)

We investigated the role of repetition for place learning in children although the acquisition of organizing spatial concepts is often seen as more essential. In a reaction-time accuracy task, 7- and 9-year-old children were presented with a randomized sequence of objects-in-places. In a novelty condition (NC), memory sets in different colors were presented, while in a repetition condition (RC), the identical memory set was tested several times. Shape memory deteriorated more than place memory in the NC, but also stayed superior to place memory when both improved in the RC. False alarms occurred for objects and places in the same way in 7-year-olds in the NC, but were negligible for 9-year-olds. In contrast, false alarms in the RC occurred in both age groups mainly for place memory. The Common Region Test (CRT) predicted reaction times only in the novelty condition, indicating use of spatial concepts. Importantly, reaction times for shapes were faster than for places at the beginning of the experiment but slowed down thereafter, while reaction times for places were slow at the beginning of the experiment but accelerated considerably thereafter. False alarms and regulation of reaction times indicated that repetition facilitated true abstraction of information leading to place learning without spatial concepts., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The study reported here examined the effect of repetition on age differences in associative recognition using a paradigm designed to encourage recollection at test. Young and older adults studied lists of unrelated word pairs presented one, two, four, or eight times. Test lists contained old (intact) pairs, pairs consisting of old words that had been studied with other partners (rearranged lures), and pairs consisting of two unstudied words (new lures). Participants gaveold/newresponses and then indicated whether their responses were based on details that they could recollect or on familiarity. Older adults exhibited an ironic effect of repetition—an increase in false alarms on rearranged lures with more study opportunities—whereas young adults did not. Older adults also claimed to recall details of the study episode for rearranged lures whose constituent words were presented more frequently, but this was not true for young adults. Although both young and older adults said that they based correct rejections of rearranged lures on memory for details of the study episode, this effect was stronger for young adults. The observed age differences are consistent with older adults having reduced use of recollection in associative recognition tasks. [ABSTRACT FROM AUTHOR]

Memory is better when learning events are spaced, as compared with massed (i.e., the spacing effect). Recent theories posit that retrieval of an item's earlier presentation contributes to the spacing effect, which suggests that individual differences in the ability to retrieve an earlier event may influence the benefit of spaced repetition. The present study examined (1) the difficulty of task demands between repetitions, which should modulate the ability to retrieve the earlier information, and (2) individual differences in working memory in a spaced repetition paradigm. Across two experiments, participants studied a word set twice, each separated by an interval where duration was held constant, and the difficulty of the intervening task was manipulated. After a short retention interval following the second presentation, participants recalled the word set. Those who scored high on working memory measures benefited more from repeated study than did those who scored lower on working memory measures, regardless of task difficulty. Critically, a crossover interaction was observed between working memory and intervening task difficulty: Individuals with low working memory scores benefited more when task difficulty was easy than when it was difficult, but individuals with high working memory scores produced the opposite effect. These results suggest that individual differences in working memory should be considered in optimizing the benefits of repetition learning. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, dense sensor event-related potentials were measured in spider-phobic individuals and non-anxious controls during incidental encoding of phobia-relevant spider and standard neutral, unpleasant and pleasant pictures. Stimulus repetition effects were assessed by presenting each picture twice — in the first and in the second half of the session. Repeated presentation of standard pleasant, unpleasant and neutral pictures resulted in a late ERP repetition effect that was similarly pronounced in both experimental groups and for all picture categories. Moreover, relative to non-fearful controls spider-phobic individuals showed an overall greater early ERP repetition effect starting at 180ms after picture onset. At later stages of evaluative processing, repeated as compared with initial presentation of phobia-relevant spider pictures elicited reduced ERP amplitudes over centro-parietal sites (480–580ms) in spider-phobic but not in control individuals. This pattern of results indicates that in small animal phobics long lasting exposure to their feared pictures leads to an increased mobilization of the perceptual analysis system, an effect that might help to improve emotional control and/or facilitate strategic avoidance of threat resulting in a diminished evaluative threat processing. This phobia-specific processing mechanism might prevent effective stimulus processing and hinder the habituation process during treatment. [Copyright &y& Elsevier]

Numerous studies have shown that repetition of search-relevant attributes facilitates visual search performance. For example, Maljkovic and Nakayama () showed that when observers search for a target defined by its color and report its shape, repetition of the target color speeds search, an effect known as priming of pop-out. While intertrial feature priming in search was initially thought to affect perceptual processes, the idea that it also affects postselection stages of processing is increasingly acknowledged. However, because in previous studies repetition of the motor response has typically been confounded with repetition of the response feature, it is not clear what mechanisms underlie the postselection effect of intertrial priming. In the present study, we dissociated the two repetition types. The results showed that repetition of the target-defining attribute from the previous trial affects selection of the motor response but not discrimination of the response attribute. The implications for current accounts of intertrial priming are discussed. [ABSTRACT FROM AUTHOR]

There is general agreement that repetition enhances various kinds of memory performance, but it remains unclear how repetition of identical items affects judgments of recency (JOR). The present study examined implicit repetition effects on JOR and the relationship between JOR and explicit judgments of frequency (JOF). Participants learned three lists consisting of 13 items, some of which were repeated from once to four times, and after learning each list, they judged how many times each list item was presented. Only after learning all three lists, participants could recognize the number of lists, and were asked to perform a temporal list discrimination task. The results showed that there was no significant effect of repetition on the accuracy of list discrimination but the response times for the most frequent items were significantly shorter. The results also showed a significant positive correlation between the accuracy of list discrimination and of JOF. These results suggest that higher frequency does not improve the accuracy of JOR, but intensifies the sense of easiness for the judgments, and that the ability to judge frequency contributes to JOR. [ABSTRACT FROM AUTHOR]

Priming effects of ignored distractor words were investigated in a task-switching situation that allowed an orthogonal variation of priming and response compatibility between prime and probe. Across 3 experiments, the authors obtained a disordinal interaction of priming and response relation. Responding was delayed in the ignored repetition condition if different responses were required for identical stimuli in the prime and probe (negative priming). Repeating the prime distractor in the probe facilitated responding if the same response was required in the prime and in the probe (positive priming). The same pattern of results was replicated in a letter-matching task without task switching (Experiment 4). Findings lend support to a new model that explains negative priming in terms of an automatic retrieval of incidental stimulus-response associations. [ABSTRACT FROM AUTHOR]

The modulation of event-related potentials by word repetition was investigated in two experiments. In both experiments, subjects responded to occasional nonwords interspersed among a series of words. A proportion of the words were repetitions of previously presented items. Words were repeated after 0 or 6 intervening items in Experiment 1 and after 6 or 19 items in Experiment 2. Event-related potentials to repeated words were characterised by a sustained, widespread positive-going shift with in onset of approximately 300 ms. This effect did not vary significantly as a function of lag in either experiment. When words were repeated immediately, this repetition evoked positive shirt was preceded by a transient negative deflection (onset ca. 200 ms) which was absent in event-related potentials to words repeated at longer lags. These results suggest that the modulation of event-related potentials by word repetition is influenced by at least two processes. One of these processes acts relatively early during the processing of a repeated word, but subsides rapidly as inter-item lag between first fad second presentations increases. The second process occurs inter in time, but is considerably more robust over variations in inter-item lag. [ABSTRACT FROM AUTHOR]