Visual distraction during word-list retrieval does not consistently disrupt memory.

Glenberg et al. (1998) reported that episodic memory is impaired by visual distraction and argued that this effect is consistent with a trade-off between internal and external attentional focus. However, their demonstration that visual distraction impairs memory for lists used 15 consecutive word-lists, with analysis only of mid-list items, and has never been replicated. Experiment 1 (N = 37) replicated their methodology and found the same pattern of impairment for mid-list recall, but found no evidence of impairment for other items on the lists. Experiment 2 (N = 64) explored whether this pattern arises because the mid-list items are poorly encoded (by manipulating presentation rate) or because of interference. Experiment 3 (N = 36) also looked at the role of interference whilst controlling for potential item effects. Neither study replicated the pattern seen in Experiment 1, despite reliable effects of presentation rate (Experiment 2) and interference (Experiments 2 and 3). Experiment 2 found no effect of distraction for mid-list items, but distraction did increase both correct and incorrect recall of all items suggestive of a shift in willingness to report. Experiment 3 found no effects of distraction whatsoever. Thus, there is no clear evidence that distraction consistently impairs retrieval of items from lists and therefore no consistent evidence to support the embodied cognition account used to explain the original finding.

Do stimulus--action associations contribute to repetition priming?

Despite evidence that response learning makes a major contribution to repetition priming, the involvement of response representations at the level of motor actions remains uncertain. Levels of response representation were investigated in 4 experiments that used different tasks at priming and test. Priming for stimuli that required congruent responses across 2 tasks was compared with that for stimuli requiring incongruent responses. Congruent responses showed more priming than incongruent responses did when congruence involved both decisions and actions (Experiment 1), decisions only (Experiment 2), and actions only (Experiment 4) but not when decision and action congruence were set in opposition (Experiment 3). These results demonstrate response learning with response representations at the level of both decisions and actions.

How should witnesses regulate the accuracy of their identification decisions: one step forward, two steps back?

Explorations of memory accuracy control normally contrast forced-report with free-report performance across a set of items and show a trade-off between memory quantity and accuracy. However, this memory control framework has not been tested with lineup identifications that may involve rejection of all alternatives. A large-scale (N = 439) lineup study explored regulation of identification decisions either with an initial forced-choice decision followed by free-report decision or with the reverse. Overall, initial free-report decisions provided stronger evidence of suspect guilt than forced-choice decisions, with little cost to memory quantity. The 2 response orders produced different patterns of response associated with control of accuracy. A model based on evaluation of the strength of the best candidate answer was able to provide only a partial fit to the data, suggesting that witnesses use more than simple memory strength of a candidate answer when controlling the accuracy of their responses in free report.

Improving eyewitness identification accuracy by screening out those who say they don't know.

Improving eyewitness identification evidence remains a key priority for research. Basic laboratory research has consistently demonstrated that allowing participants to withhold answers about which they are unsure leads to improved accuracy. Surprisingly, this approach has not been the subject of comprehensive investigation in the eyewitness identification literature. In this article, we explored the utility of allowing uncertain witnesses to opt out of an identification decision, by providing an explicit don't know option. Further, we contrasted the rate of use of this explicit option with the frequency that participants spontaneously withheld a decision when asked to respond in their own words. Four hundred and twenty participants witnessed a mock crime video before being presented with a showup of the perpetrator or an innocent suspect. Participants were tested either immediately or after a 3-week delay, with one of the three report options: Participants either made their choice in their own words (spontaneous report), chose between identifying and rejecting the showup (forced-report), or chose between identification, rejection and don't know (free-report). Only 2.2% of witnesses spontaneously used a don't know response, compared to 19.3% who used it when the option was explicit. Compared with the forced-report decisions, free-report decisions were more accurate, more diagnostic of the suspect's guilt or innocence, and came at no cost to the number of correct decisions rendered. These data suggest that utilisation of an explicit don't know option may be of practical value.

Retrieval-induced forgetting in recognition is absent under time pressure.

We examined retrieval-induced forgetting (RIF) in recognition from a dual-process perspective, which suggests that recognition depends on the outputs of a fast familiarity process and a slower recollection process. In order to determine the locus of the RIF effect, we manipulated the availability of recollection at retrieval via response deadlines. The standard RIF effect was observed in a self-paced test but was absent in a speeded test, in which judgments presumably depended on familiarity more than recollection. The findings suggested that RIF specifically affects recollection. This may be consistent with a context-specific view of retrieval inhibition.

Eye closure reduces the cross-modal memory impairment caused by auditory distraction.

Eyewitnesses instructed to close their eyes during retrieval recall more correct and fewer incorrect visual and auditory details. This study tested whether eye closure causes these effects through a reduction in environmental distraction. Sixty participants watched a staged event before verbally answering questions about it in the presence of auditory distraction or in a quiet control condition. Participants were instructed to close or not close their eyes during recall. Auditory distraction did not affect correct recall, but it increased erroneous recall of visual and auditory details. Instructed eye closure reduced this effect equally for both modalities. The findings support the view that eye closure removes the general resource load of monitoring the environment rather than reducing competition for modality-specific resources.

Effects of study list composition on the word frequency effect and metacognitive attributions in recognition memory.

In two experiments, study-list composition was manipulated and its impact was observed on metacognitive judgements associated with recognition hits (Hs) and false alarms (FAs). Both studies involved recognition of high-frequency (HF) and low-frequency (LF) words, and focused on the FA portion of the word frequency effect. Our hypothesis was that participants can actively reject items that are distinctive from the study list, and that this effect may be strong enough to overcome the FA word frequency effect. Experiment 1 manipulated list composition with a conjunctive rule and Experiment 2 varied it by having participants study either HF or LF items prior to a test consisting of words of both frequencies. In each study H rate, FA rate, and metacognitive attributions underlying recognition decisions were investigated. In both studies, participants reported rejecting test items predominantly through a process of active rejection, which was more often reported for LF items. This effect was strong enough to reverse the FA portion of the word frequency effect in Experiment 2, but not Experiment 1. The results are discussed in terms of metacognitive rejection mechanisms in recognition memory.

Temporal distance and person memory: thinking about the future changes memory for the past.

Psychological distance has been shown to influence how people construe an event such that greater distance produces high-level construal (characterized by global or holistic processing) and lesser distance produces low-level construal (characterized by detailed or feature-based processing). The present research tested the hypothesis that construal level has carryover effects on how information about an event is retrieved from memory. Two experiments manipulated temporal distance and found that greater distance (high-level construal) improves face recognition and increases retrieval of the abstract features of an event, whereas lesser distance (low-level construal) impairs face recognition and increases retrieval of the concrete details of an event. The findings have implications for transfer-inappropriate processing accounts of face recognition and event memory, and suggest potential applications in forensic settings.

Sizing up the associative account of repetition priming.

Three studies which test an associative account of repetition priming in a size comparison task are reported. Congruence of decision between priming and test affected performance when the priming task and test tasks were the same but not when they differed. This congruence effect was unaffected by the proportion of trials with congruent responses. Same-task priming exceeded cross-task priming even when both tasks required the same aspect of semantic knowledge. The results indicate that a component of priming is due to associations which are formed during priming and automatically activated when stimuli are repeated at test. Stimuli do not become associated with motor responses but are associated with the results of processing at a number of other levels.

Global subjective memorability and the strength-based mirror effect in recognition memory.

Between-list manipulations of memory strength through repetition commonly generate a mirror effect, with more hits and fewer false alarms for strengthened items. However, this pattern is rarely seen with within-list manipulations of strength. In three experiments, we investigated the conditions under which a within-list mirror effect of strength (items presented once or thrice) is observed. In Experiments 1 and 2, we indirectly manipulated the overall subjective memorability of the studied lists by varying the proportion of nonwords. A within-list mirror effect was observed only in Experiment 2, in which a higher proportion of nonwords was presented in the study list. In Experiment 3, the presentation duration for each item (0.5 vs. 3 sec) was manipulated between groups with the purpose of affecting subjective memorability. A within-list mirror effect was observed only for the short presentation durations. Thus, across three experiments, we found the within-list mirror effect only under conditions of poor overall subjective memorability. We propose that when the overall subjective memorability is low, people switch their response strategy on an item-by-item basis and that this generates the observed mirror effect.

Investigating strength and frequency effects in recognition memory using type-2 signal detection theory.

Criterion- versus distribution-shift accounts of frequency and strength effects in recognition memory were investigated with Type-2 signal detection receiver operating characteristic (ROC) analysis, which provides a measure of metacognitive monitoring. Experiment 1 demonstrated a frequency-based mirror effect, with a higher hit rate and lower false alarm rate, for low frequency words compared with high frequency words. In Experiment 2, the authors manipulated item strength with repetition, which showed an increased hit rate but no effect on the false alarm rate. Whereas Type-1 indices were ambiguous as to whether these effects were based on a criterion- or distribution-shift model, the two models predict opposite effects on Type-2 distractor monitoring under some assumptions. Hence, Type-2 ROC analysis discriminated between potential models of recognition that could not be discriminated using Type-1 indices alone. In Experiment 3, the authors manipulated Type-1 response bias by varying the number of old versus new response categories to confirm the assumptions made in Experiments 1 and 2. The authors conclude that Type-2 analyses are a useful tool for investigating recognition memory when used in conjunction with more traditional Type-1 analyses.

Source credibility and idea improvement have independent effects on unconscious plagiarism errors in recall and generate-new tasks.

Unconscious plagiarism occurs when people try to generate new ideas or when they try to recall their own ideas from among a set generated by a group. In this study, the factors that independently influence these two forms of plagiarism error were examined. Participants initially generated solutions to real-world problems in 2 domains of knowledge in collaboration with a confederate presented as an expert in 1 domain. Subsequently, the participant generated improvements to half of the ideas from each person. Participants returned 1 day later to recall either their own ideas or their partner's ideas and to complete a generate-new task. A double dissociation was observed. Generate-new plagiarism was driven by partner expertise but not by idea improvement, whereas recall plagiarism was driven by improvement but not expertise. This improvement effect on recall plagiarism was seen for the recall-own but not the recall-partner task, suggesting that the increase in recall-own plagiarism is due to mistaken idea ownership, not source confusion.

The effects of precedence on Navon-induced processing bias in face recognition.

Macrae and Lewis (2002) showed that repeated reporting of the global dimension of Navon stimuli improved performance in a subsequent face identification task, whilst reporting the features of the Navon stimuli impaired performance. Using a face composite task, which is assumed to require featural processing, Weston and Perfect (2005) showed the complementary pattern: Featural responding to Navon letters speeded performance. However, both studies used Navon stimuli with global precedence, in which the overall configuration is easier to report than the features. Here we replicate the two studies above, whilst manipulating the precedence (global or featural) of the letter stimuli in the orientation task. Both studies replicated the previously reported findings with global precedence stimuli, but showed the reverse pattern with local precedence stimuli. These data raise important questions as to what is transferred between the Navon orientation task and the face-processing tasks that follow.

Why do I always have the best ideas? The role of idea quality in unconscious plagiarism.

Groups of individuals often work together to generate solutions to a problem. Subsequently, one member of the group can plagiarise another either by recalling that person's idea as their own (recall-own plagiarism), or by generating a novel solution that duplicates a previous idea (generate-new plagiarism). The current study examines the extent to which these forms of plagiarism are influenced by the quality of the ideas. Groups of participants initially generated ideas, prior to an elaboration phase in which idea quality was manipulated in two ways: participants received feedback on the quality of the ideas as rated by independent judges, and they generated improvements to a subset of the ideas. Unconscious plagiarism was measured in recall-own and generate-new tasks. For recall, idea improvement led to increased plagiarism, while for the generate-new task, the independent ratings influenced plagiarism. These data indicate that different source-judgement processes underlie the two forms of plagiarism, neither of which can be reduced simply to memory strength.

Differential effects of aging on executive and automatic inhibition.

One of the major accounts of cognitive aging states that age effects are related to a deficiency of inhibitory mechanisms (Hasher & Zacks, 1988). Given that inhibition has traditionally been associated with the frontal cortex, and that the frontal cortex deteriorates early with age (Raz, 2000), this is consistent with the frontal hypothesis of aging (West, 1996). However, not all inhibitory processes require executive control, and so they are not all equally supported by the frontal cortex. As a consequence, one would expect dissociations between inhibitory tasks in the sense of a greater susceptibility of executive/frontal inhibition to aging. Based on Nigg's (2000) working inhibition taxonomy, we tested this hypothesis by combining inhibitory paradigms with different levels of executive control within the same participants. The results showed that age affects Stroop interference but not negative priming (Experiment 1) and stop signal responsiveness but not negative priming (Experiment 2). These findings suggest that tasks with a high executive (or effortful) inhibitory control are more sensitive to aging than tasks with a lower executive (more automatic) inhibitory control. The results are discussed in relation to the inhibitory and frontal accounts of aging.

The effects of repeated idea elaboration on unconscious plagiarism.

Unconscious plagiarism occurs in a recall task when someone presents someone else's idea as his or her own. Recent research has shown that the likelihood of such an error is inflated if the idea is improved during the retention interval, but not if it is imagined. Here, we explore the effects of repeating the elaboration phase during the retention interval. Participants in a group first generated alternate uses to common objects before elaborating the ideas either by imagining them or by improving them. This elaboration phase occurred once, twice, or not at all. Later, they attempted to recall their original ideas and generate new ideas. Repeated imagery did not inflate unconscious plagiarism on either task. In contrast, repeating the improvement phase increased plagiarism to dramatically high levels in the recall task. The latter effect might be particularly pertinent to real-world cases of plagiarism in which the ideas under dispute have been the subject of creative development over many occasions.

Counterintuitive and alternative moves choice in the Water Jug task.

MOVE problems, like the Tower of London (TOL) or the Water Jug (WJ) task, are planning tasks that appear structurally similar and are assumed to involve similar cognitive processes. Carder et al. [Carder, H.P., Handley, S.J., & Perfect, T.J. ( 2004). Deconstructing the Tower of London: Alternative moves and conflict resolution as predictors of task performance. The Quarterly Journal of Experimental Psychology 57a, 8, 1459-1483] showed that one predictor of TOL performance was the number of alternative move choices there were at a given point in the solution. In two experiments an individual move experienced on the WJ task was manipulated (perceptually consistent/counterintuitive) along with the number of alternative moves there were to choose between. A verification paradigm was employed in which participants made speeded judgements about the correctness of a move. Results showed performance was consistent with the application of a perceptual strategy accompanied by a process involving the evaluation of non-redundant alternative moves. These are discussed in the context of recent research that has examined the impact of executive dysfunction on Water Jug performance [Colvin, M.K., Dunbar, K., & Grafman, J. (2001). The effects of frontal lobe lesions on goal achievement in the Water Jug task. Journal of Cognitive Neuroscience, 13, 1129-1147].

How can we help witnesses to remember more? It's an (eyes) open and shut case.

Five experiments tested the idea that instructing a witness to close their eyes during retrieval might increase retrieval success. In Experiment 1 participants watched a video, before a cued-recall test for which they were either instructed to close their eyes, or received no-instructions. Eye-closure led to an increase in correct cued-recall, with no increase in incorrect responses. Experiments 2-5 sought to test the generality of this effect over variations in study material (video or live interaction), test format (cued- or free-recall) and information modality (visual or auditory details recalled). Overall, eye-closure increased recall of both visual detail and auditory details, with no accompanying increase in recall of false details. Collectively, these data convincingly demonstrate the benefits of eye-closure as an aid to retrieval, and offer insight into why hypnosis, which usually involves eye-closure, may facilitate eyewitness recall.

The effects of local and global processing orientation on eyewitness identification performance.

Recent work has demonstrated that performance on a simultaneous target-present photographic line-up can be enhanced by prior global processing orientation, and hindered by prior local processing orientation induced by processing Navon letter stimuli. A series of studies explore the generality of this processing bias effect using either videotaped scenarios or live interactions. Five experiments demonstrate that these effects are seen across a range of test stimuli, test formats, and test instructions. These data inform the processes engaged in by witnesses when making line-up identifications and indicate that it may be possible to improve the accuracy of witnesses making such judgements.