The effects of cue distinctiveness on odor-based context-dependent memory

The distinctiveness of an ambient odor was examined in relation to its success as a cue in contextdependent memory. Distinctiveness was examined in terms of both cue novelty and contextual appropriateness. Two experiments were conducted in which three different ambient odors that varied in familiarity and contextual appropriateness were manipulated at an incidental word learning encoding session and at a free recall retrieval session 48 h later. Experiment 1 revealed that when a novel ambient odor (osmanthus) was the available context cue, word recall was better than in any other condition. Further, among familiar odor cues, recall was better with a contextually inappropriate odor (peppermint) than with a contextually appropriate odor (clean fresh pine). Experiment 2 confirmed that superior word recall with osmanthus and peppermint depended on the odor cue’s being available at both encoding and retrieval, and that the relation of an odor to the situational context is a key factor for predicting its effectiveness as a retrieval cue.     

Differential effects of cue dependency on item and source memory

The authors investigated the cue dependency of source and item memory. Individuals listened to words spoken by a man or a woman and later determined whether a test word was previously presented by a man or by a woman, or whether it was a new word. Cue dependent effects were assessed by presenting test words with (a) the same voice (match condition) that originally presented the word, (b) a different but familiar voice (mismatch condition), (c) a novel test voice (novel condition), and (d) no test voice (control condition). Compared with the control condition, source recollection was facilitated in matching-context conditions, disrupted in mismatching-context conditions, and not affected in novel test conditions. By contrast, item recognition was not affected by the match-mismatch manipulation but was significantly worse in novel test voice conditions. The authors propose an associative source interference view to account for the voice match-mismatch effects observed in source recollection.     

The effects of implementation intention strategies on prospective memory cue encoding

Implementation intentions, which include a structured verbal statement and mental imagery, improve prospective memory performance (i.e. remembering to execute delayed intentions). To investigate whether, and how, implementation intention strategies affect encoding processes we had participants complete a thought probe procedure immediately after forming the intention to remember to press Q when seeing fruit words. In Experiment 1, an implementation intention verbal statement (relative to control statement) significantly increased generation of high typicality exemplars (apple, banana, orange). In Experiment 2, an implementation intention imagery procedure (relative to control imagery) produced similar outcomes. In Experiment 3, combining the statement and imagery components of the implementation intention (relative to control statement and imagery) demonstrated even more potent effects (e.g. three-fold increase in fruit exemplars generated). In Experiment 4, we tested whether the control statement versus control imagery procedure differentially affected encoding, but these control procedures showed no significant differences. An interesting, unanticipated finding was that there was significantly less mind wandering in the implementation intention conditions relative to the control conditions. The current experiments provide novel information on the processes operating during intention encoding, and support the classic view that implementation intentions increase the encoding of specific retrieval cues.     

The effects of search criteria and retrieval cue availability on memory for words

The effects of search criteria upon recall performance following a word classification task were investigated. Rival hypotheses were tested, one based on the number of cues available at retrieval and the other on the amount of processing carried out during classification. After being presented with two-component category names, subjects classified words on the basis of either category membership or the number of semantic components the words shared with a target category, and then they received an unexpected recall test. Experiment 1 favored an amount-of-processing explanation, but it was felt that redundancy in the stimulus materials might invalidate this conclusion. Experiment 2 confirmed this suspicion and clearly supported an explanation in terms of retrieval cue availability. The notion of partial semantic processing of words is discussed, and it is argued that the number of congruent encodings formed during classification can be used as an index of elaboration and subsequent memory performance.     

Prospective memory across adolescence: the effects of age and cue focality

The present study examined the role of controlled attention in age differences in event-based prospective memory performance across adolescence. The researchers tested whether presenting the prospective memory cue in or out of focal awareness of the ongoing task (resulting in low versus high demands for controlled attention, respectively) might affect age-related prospective memory performance. In total, 119 Chinese participants ages 13 to 20 took part in this study (60 adolescents: age M = 13.26 years, SD = 0.50; 23 boys; 59 young adults: age M = 19.70 years, SD = 0.87; 19 men). Findings demonstrated a significant interaction, F(1, 114) = 6.41, p < .05. No effect of age on prospective memory performance was revealed when a focal cue was used (F < 1), whereas there was a reliable age effect between adolescents and young adults when nonfocal prospective memory cues were presented, F(1, 59) = 16.13, p < .01. This pattern of results suggests that the interplay of both available resources of controlled attention and working memory, along with specific task demands, may contribute to possible age differences in prospective memory performance across adolescence. Results are discussed in the context of the multiprocess theory of prospective memory.     

Age-differential effects on updating cue information: Evidence from event-related potentials

Recent models on cognitive aging consider the ability to maintain and update context information to be a key source of age-related impairments in various cognitive tasks (Braver & Barch in Neuroscience & Biobehavioral Reviews, 26: 809–817, 2002). Context updating has been investigated with a modified AX-continuous-performance task by comparing performance and brain activity between context-dependent trials (i.e., correct responses require updating of the preceding cue information) and context-independent trials (i.e., correct responses are independent of cue information). We used an event-related potential (ERP) approach to identify sources of age differences in context processing in the early and late processing of cue information. Our behavioral data showed longer latencies and higher error rates on context-dependent than on context-independent trials for older than for younger adults, suggesting age-related impairments in context updating. The ERP data revealed larger P3b amplitudes for context-dependent than for context-independent trials only in younger adults. In contrast, in older adults, P3b amplitudes were more evenly distributed across the scalp and did not differ between context conditions. Interestingly, older but not younger adults were sensitive to changes of cue identity, as indicated by larger P3b amplitudes on cue-change than on cue-repeat trials, irrespective of the actual context condition. We also found a larger CNV on context-dependent than on context-independent trials, reflecting active maintenance of context information and response preparation. The age-differential effects in the P3b suggest that both younger and older adults were engaged in updating task-relevant information, but relied on different information: Whereas younger participants indeed relied on context cues to update and reconfigure the task settings, older adults relied on changes in cue identity, irrespective of context information.     

Practice and feedback effects on the confidence-accuracy relation in eyewitness memory

It has been claimed that the lack of a reliable confidence-accuracy relation in eyewitness memory stems from eyewitnesses' lack of knowledge concerning their relative expertise. Two studies tested this idea by contrasting the effects of practice alone with practice with feedback in three successive eyewitness tests. Experiment 1 tested recall for events, and Experiment 2 used recognition of faces as test materials. Both studies showed that practice alone did not increase the confidence-accuracy relation, but practice with feedback on relative performance produced robust increases in the confidence-accuracy relation. This suggests that lack of calibration is one factor that causes the reported lack of association between confidence and accuracy for eyewitness memory.     

Practice and feedback effects on the confidence-accuracy relation in eyewitness memory

It has been claimed that the lack of a reliable confidence-accuracy relation in eyewitness memory stems from eyewitnesses' lack of knowledge concerning their relative expertise. Two studies tested this idea by contrasting the effects of practice alone with practice with feedback in three successive eyewitness tests. Experiment 1 tested recall for events, and Experiment 2 used recognition of faces as test materials. Both studies showed that practice alone did not increase the confidence-accuracy relation, but practice with feedback on relative performance produced robust increases in the confidence-accuracy relation. This suggests that lack of calibration is one factor that causes the reported lack of association between confidence and accuracy for eyewitness memory.     

Age-related effects in prospective memory are modulated by ongoing task complexity and relation to target cue

Two experiments examined the puzzling variation in the age-related patterns for event-based prospective memory tasks. Both experiments involved a famous faces ongoing task with a feature of the famous face as the target for the prospective memory task. In Experiment 1, a substantial age deficit was found on the prospective memory task when the cue was nonfocal (wearing glasses) to the ongoing task, replicating previous research, but this deficit was significantly reduced with a focal cue (first name John). In Experiment 2, the prospective memory cue (wearing glasses) was held constant and the demands of the ongoing task of naming faces were varied. The substantial age differences found with a nonfocal cue were eliminated when the ongoing task was made less challenging. The findings help reconcile the divergent age-related findings reported in the literature.     

Age effects in emotional prospective memory: cue valence differentially affects the prospective and retrospective component

While first studies suggested that emotional task material may enhance prospective memory performance in young and older adults, the extent and mechanisms of this effect are under debate. The authors explored possible differential effects of cue valence on the prospective and retrospective component of prospective memory in young and older adults. Forty-five young and 41 older adults performed a prospective memory task in which emotional valence of the prospective memory cue was manipulated (positive, negative, neutral). The multinomial model of event-based prospective memory was used to analyze effects of valence and age on the two prospective memory components separately. Results revealed an interaction indicating that age differences were smaller in both emotional valence conditions. For older adults positive cues improved the prospective component, while negative cues improved the retrospective component. No main effect of valence was found for younger adults on an overt accuracy measure, but model-based analyses showed that the retrospective component was enhanced in the positive compared with the negative cue condition. The study extends the literature in demonstrating that processes underlying emotional effects on prospective memory may differ depending on valence and age.     

Environmental cue saliency influences the vividness of a remote spatial memory in rats

The Morris water maze is frequently used to evaluate the acquisition and retrieval of spatial memories. Few experiments, however, have investigated the effects of environmental cue saliency on the strength or persistence of such memories after a short vs. long post-acquisition interval. Using a Morris water maze, we therefore tested in rats the effect of the saliency of distal cues on the vividness of a recent (5 days) vs. remote (25 days) memory. Rats trained in a cue-enriched vs. a cue-impoverished context showed a better overall level of performance during acquisition. Furthermore, the probe trials revealed that the rats trained and tested in the cue-impoverished context (1) spent less time in the target quadrant at the 25-day delay, and (2) swam shorter distances in the target area, with fewer crossings at both 5- and 25-day delays, as compared to their counterparts trained and tested in the cue-enriched context. Thus, the memory trace formed in the cue-enriched context shows better resistance to time, suggesting an implication of cue saliency in the vividness of a spatial memory.     

A single unstable visual cue impairs spatial learning in a water maze

The role of a prominent visual cue (a light) in spatial learning was examined. Rats were trained to locate a hidden platform in a 4-arm radial water maze. For some rats the light predicted platform location. For other rats the light moved from trial to trial and did not predict platform location. While the predictive light did not facilitate performance above that seen in rats trained without a light, the moving light significantly impaired performance. In a second experiment, the temporal parameters of the moving light were manipulated. For one group the light was visible for the entire trial. In a second group the light was visible only before the rats reached the platform and in a third group the light was visible only after the rats reached the platform. The moving light impaired performance only when it was presented for the entire trial. When rats were subsequently retrained with a new platform location and a moving light in the familiar room, the light did not impair performance in any of the groups. We suggest that the prominent visual cue served as a directional cue, that competed with other directional cues, in the unfamiliar environment and interfered with performance.     

On sensitive rank tests for comparing the effects of two treatments on a single group

The rank testR _n of Cronholm and Revusky [1965] in effect doubles the number of comparisons carried out in the Mann-Whitney test between Treated and Control subjects chosen from a single group ofn and triples the asymptotic Pitman efficiency against shift alternatives by using a series ofn — 1 subexperiments. However, the full series can be too costly or time-consuming. It is shown thatj appropriately chosen subexperiments will permit one to make at leastj/(j+1) of the number of comparisons possible underR _n, with large sample efficiency ofj/(j+2) relative toR _n against shift alternatives and small sample efficiency greater than that,j=2, 3, ...,n — 2. The resulting test criterion is a sum ofj independent Mann-Whitney test statistics. Its null distribution is tabulated forn10 and small sample efficiency comparisons are carried out forn=10.     

A sensitive rank test for comparing the effects of two treatments on a single group

By taking advantage of an experimental design which increases the number of observations per subject, the sensitivity of the proposed test is increased. In the first of a series of subexperiments, the score of a randomly selected experimentalS is ranked with the scores of the remaining (control)Ss, and the experimentalS is discarded. This procedure is repeated until oneS remains. The test criterion,R _n , is the sum of ranks of the experimentalSs; its exact sampling distribution, a normal approximation, and the sensitivity of the test relative to the WilcoxonT, are described. Because of the large number of scores obtained, the test is particularly useful when preparingSs is more costly than testing them, e.g., in tests following involved conditioning procedures. Since eachS is discarded after experimental treatment, the test fills a real need in studies involving radiation, ablation, or other irreversible treatments.The test criterion, the associated experimental procedure, and the measure of sensitivity are due to SHR; the generating function, tables, and large sample approximation are due to JNC.     

The effects of a discriminative cue and an incompatible activity on generalized imitation

Four noncompliant retardates were observed in a generalized imitation study. Two variables were studied: provision of a competing reinforced activity, and use of a cue to aid discrimination between reinforced and nonreinforced imitations. Both variables were found to increase the rate of discrimination between the two sets of stimuli. Greatest discrimination occurred when both cue and alternative task were present. Discrimination decreased when the variables were removed. Results are interpreted as implying that imitation of nonreinforced cues in generalized imitation procedures varies with the degree to which reinforcement is available for other activity, as well as with the complexity of the discrimination problem. These results help indicate conditions under which the generalized imitation effect may be observed in more naturalistic settings.     

编码方式对汉字短时记忆提取的影响

短时记忆提取是认知心理学研究中的重要课题之一。自Sternberg(1 966)提出短时记忆提取作的是序列的从头到尾的完全搜索以来 ,许多研究者对短时记忆提取进行了广泛的研究 ,提出了序列的自动停止的搜索、平行加工、直接存取 ,以及序列搜索和直接存取双重模型等许多不同看法 ,引起了激烈争论。本研究的目的是试图探索编码方式对汉字短时记忆提取的影响。实验运用Sternberg的“探测法” ,以随机排列的汉字作识记组和探测项刺激。实验结果表明 :编码方式对汉字短时记忆提取有很大影响 ,当用声音编码方式提取短时记忆汉字时 ,被试倾向于从头到尾的完全的搜索 ;当用形状编码时 ,被试倾向于作自动停止的搜索。     

Effects of self-relevant cues and cue valence on autobiographical memory specificity in dysphoria

Reduced autobiographical memory specificity (rAMS) is a characteristic memory bias observed in depression. To corroborate the capture hypothesis in the CaRFAX (capture and rumination, functional avoidance, executive capacity and control) model, we investigated the effects of self-relevant cues and cue valence on rAMS using an adapted Autobiographical Memory Test conducted with a nonclinical population. Hierarchical linear modelling indicated that the main effects of depression and self-relevant cues elicited rAMS. Moreover, the three-way interaction among valence, self-relevance, and depression scores was significant. A simple slope test revealed that dysphoric participants experienced rAMS in response to highly self-relevant positive cues and low self-relevant negative cues. These results partially supported the capture hypothesis in nonclinical dysphoria. It is important to consider cue valence in future studies examining the capture hypothesis.