Implicit memory for new associations: The pictorial influence

A series of experiments was conducted in order to show that implicit memory for new associations is not always dependent on semantic integrative processing during study. The material used in these experiments differed from traditional studies that employed pairs of unrelated words. Instead, targets (words in Exps. 1 and 2 and pictures in Exps. 3 and 4) were encoded in the context of an unrelated picture. The implicit tests used were word-stem completion (Exps. 1, 2, and 3) and picture-fragment identification (Exp. 4). The explicit test was word-stem cued recall (Exps. 1, 2, and 3) and picture-fragment cued recall (Exp 4). For implicit tests, context effects were not obtained using words as targets with a non-integrative semantic-elaboration encoding task (Exp. 1). When an integrative semantic-elaboration encoding task was used, a standard context effect emerged (Exp. 2) for implicit memory. Importantly, with pictures as targets, context effects appeared without integrative semantic encoding (Exps. 3 and 4). However, context effects were obtained for all conditions of cued recall. Results are discussed with regard to the concept of unitization.     

Implicit memory for novel conceptual associations in amnesia

In two experiments, we evaluated the status of implicit memory for novel associations in amnesia. Experiment 1 assessed priming in a category exemplar generation task in which contextual information associated with a target could increase the likelihood of target generation. Control participants, but not amnesic patients, showed associative priming. Amnesics’ impairment was not due to the use of explicit memory by control subjects but reflected a genuine impairment in implicit memory for novel conceptual associations. Experiment 2 assessed priming in a relatedness judgment task, in which associative priming was manifest as longer latencies for old than for recombined pairs of unrelated words. Amnesic patients showed intact associative priming in this task. We discuss differences in the status of implicit memory for novel conceptual associations in amnesia, with reference to the nature of the representation that supports priming in the two tasks and the type of processing that is required at test.     

Changes in reality monitoring and episodic memory in early childhood

The purposes of this research were to examine the developmental relation between reality monitoring and episodic memory, to link reality monitoring to autobiographical memory by using extended naturalistic events, and to examine prefrontal functioning as a potential contributor to development in reality monitoring and episodic memory. In Experiment 1, 4-year-olds were worse than 6- or 8-year-olds at reality monitoring after a week delay, despite the fact that they remembered more about real than imagined events and remembered different aspects of each. In Experiments 2 and 3, reality monitoring and episodic memory were evaluated for 4- and 6-year-olds immediately after the events occurred and, in Experiment 3, again after a week delay. Reality monitoring was at higher levels for both age groups, but age differences remained. These data suggest that preschoolers' difficulties with reality monitoring result from a combination of episodic memory deficits and strategic differences. In addition, correlation analyses more directly linked preschoolers' reality monitoring to episodic memory and supported the hypothesis that episodic memory development is related to prefrontal functioning.     

Acquisition of novel traces in short-term implicit memory: Priming for nonwords and new associations

McKone (1995) reported a short-lived repetition priming effect (up to 8 sec and three intervening items), superimposed on long-term priming. In lexical decision and naming, decay of this short-term implicit memory was faster for pseudowords than for words, suggesting an explanation in terms of transient activation of preexisting lexical representations. Here, we present two cases where, in contrast, preexperimental familiarity did not affect short-term priming, indicating acquisition of novel traces. Experiment 1 determined repetition priming in same-different judgments to lowercase-uppercase pairs for words, and for nonwords with three levels of wordlikeness. Across lags of 0, 1, and 6 intervening items (2-14 sec), short-term priming was the same for all stimuli, even random letter strings. Experiments 2 and 3 assessed priming in a double lexical decision task for old associations (orange-apple) and new associations (cigar-errand). Short-term priming for the association was equal in both cases.     

Implicit and explicit memory for new associations in normal and amnesic subjects

Two experiments examined whether repetition priming effects on a word completion task are influenced by new associations between unrelated word pairs that were established during a single study trial. On the word completion task, subjects were presented with the initial three letters of the response words from the study list pairs and they completed these fragments with the first words that came to mind. The fragments were shown either with the paired words from the study list (same context) or with other words (different context). Both experiments showed a larger priming effect in the same-context condition than in the different-context condition, but only with a study task that required elaborative processing of the word pairs. This effect was observed with college students and amnesic patients, suggesting that word completion performance is mediated by implicit memory for new associations that is independent of explicit recollection.     

Individual differences in episodic memory abilities predict successful prospective memory output monitoring

Output monitoring refers to memory for one’s previously completed actions. In the context of prospective memory (PM) (e.g., remembering to take medication), failures of output monitoring can result in repetitions and omissions of planned actions (e.g., over- or under-medication). To be successful in output monitoring paradigms, participants must flexibly control attention to detect PM cues as well as engage controlled retrieval of previous actions whenever a particular cue is encountered. The current study examined individual differences in output monitoring abilities in a group of younger adults differing in attention control (AC) and episodic memory (EM) abilities. The results showed that AC ability uniquely predicted successful cue detection on the first presentation, whereas EM ability uniquely predicted successful output monitoring on the second presentation. The current study highlights the importance of examining external correlates of PM abilities and contributes to the growing body of research on individual differences in PM.     

Implicit memory for novel associations between pictures: effects of stimulus unitization and aging

Studies of implicit memory for novel associations have focused primarily on verbal materials and have highlighted the contribution of conceptually unitized representations to such priming. Using pictorial stimuli in a perceptual identification task, we examined whether new association priming can occur at a purely perceptual level. By manipulating the spatial contiguity of stimuli, we also evaluated whether such priming requires the creation of perceptually unitized representations. Finally, we examined the status of such priming in aging. In Experiment 1, we found that spatial contiguity of stimuli is not necessary for novel pictorial association priming to emerge, although such contiguity does enhance the magnitude of associative priming. In Experiment 2, we found that new association priming is age invariant, regardless of spatial contiguity. In Experiment 3, we provide additional evidence that pictorial association priming is perceptually based. These findings expand the scope and delineate the conditions of novel association priming and inform theories about the nature of implicit memory for new associations.     

The effects of interacting in repeated events on children's eyewitness memory and source monitoring

Accurate eyewitness memory of an event may be affected by exposure to and degree of involvement with other related events. In this study, we investigated whether interacting in a related video event affected children's accounts of a real-life target event, and whether interacting in the target event affected memory for different details within the target event. Four-, 6-, and 9-year-old children interacted with an adult who made a puppet. Half of the children in each age group also interacted with a video of a similar event (interactive condition) and half sat and watched the video without interacting (watch condition). When asked non-misleading questions a week later, children in the interactive condition confused the two events more than those in the watch condition. The 4-year-olds in the interactive condition reported a higher rate of confusions in free recall than the 4-year-olds in the watch condition. There were no effects of interaction on responses to misleading questions. The 6- and 9-year-olds were more accurate at answering questions related to actions they themselves had performed than actions performed by the experimenter, although this pattern was reversed for the 4-year-olds. The results are discussed in terms of children's eyewitness memory. © 1998 John Wiley & Sons, Ltd.     

Reminiscence and hypermnesia in children's eyewitness memory

Three experiments examined reminiscence and hypermnesia in 5- and 6-year-olds' memory for an event across repeated interviews that occurred either immediately afterward (Experiment 1) or after a 6-month delay (Experiments 2 and 3). Reminiscence (recall of new information) was reliably obtained in all of the experiments, although the numbers of new items recalled were fewer after a delay than when the interviews occurred immediately afterward. Hypermnesia (increasing total recall over repeated recall attempts) was obtained only in Experiment 1 when interviews occurred immediately and 24 h after the event.     

Cross-cultural differences in eyewitness memory reports

Increasingly, investigators conduct interviews with eyewitnesses from different cultures. The culture in which people have been socialised can impact the way they encode, remember, and report information about their experiences. We examined whether eyewitness memory reports of mock witnesses from collectivistic (sub-Saharan Africa) and individualistic (Northern Europe) cultures differed regarding quantity and quality of central and background details reported. Mock witnesses (total N = 200) from rural Ghana, urban Ghana, and the Netherlands were shown stimuli scenes of crimes in Dutch and Ghanaian settings and provided free and cued recalls. Individualistic culture mock witnesses reported the most details, irrespective of detail type. For each cultural group, mock witnesses reported more correct central details when crime was witnessed in their own native setting than a non-native setting, though for different recall domains. The findings provide insight for legal and investigative professionals as well as immigration officials eliciting memory reports in cross-cultural contexts.     

Source accuracy data reveal the thresholded nature of human episodic memory

Episodic recollection supports conscious retrieval of past events. It is unknown why recollected memories are often vivid, but at other times we struggle to remember. Such experiences might reflect a recollection threshold: Either the threshold is exceeded and information is retrieved, or recollection fails completely. Alternatively, retrieval failure could reflect weak memory: Recollection could behave as a continuous signal, always yielding some variable degree of information. Here we reconcile these views, using a novel source memory task that measures retrieval accuracy directly. We show that recollection is thresholded, such that retrieval sometimes simply fails. Our technique clarifies a fundamental property of memory and allows responses to be accurately measured, without recourse to subjective introspection. These findings raise new questions about how successful retrieval is determined and why it declines with age and disease.     

Autism,episodic memory,and moral exemplars

This paper presents a challenge for exemplar theories of moral concepts. Some have proposed that we acquire moral concepts by way of exemplars of actions that are prohibited as well as of actions that are required, and we classify newly encountered actions based on their similarity to these exemplars. Judgments of (im)permissibility then follow from these exemplar-based classifications. However, if this were true, then we would expect that individuals who lacked, or were deficient in, the capacity to form or access exemplars of this kind would be similarly deficient in the ability to classify new actions according to them, and this relative inability would be manifested in the moral judgments made by such individuals. However, there is reason to suspect, I think, that a number of individuals who have been diagnosed with Autism Spectrum Disorder (ASD) actually have the deficiencies I have described here but are nevertheless fully able to make sound moral judgments. If this is so, then it must be the case that classifying actions as instances of a given moral concept and making judgments based on said classification does not rely solely on exemplars.     

Implicit memory bias,explicit memory bias,and anxiety

Abstract

Normals high, medium, and low in trait anxiety performed two encoding tasks (one predominantly data-driven and the other conceptually driven) on threat-related and neutral words, followed by tests of word completion, cued recall, and free recall. Memory performance indicated the existence of negative memory biases in the high trait-anxious group, but it was generally not possible to decide whether the biases were associated with trait anxiety rather than with depression. The biases were obtained mainly when there was a match between the processes at encoding and those at the time of test, whether the matching processes were predominantly data-driven or conceptually driven. Implications of these findings for implicit and explicit memory biases associated with high trait anxiety are discussed.     

Selective retrieval and induced forgetting in eyewitness memory

This study analyses retrieval‐induced forgetting (RIF) in eyewitness memory. Selective retrieval of specific information about an event could cause eyewitnesses to forget related contents. Based on a video of a man being robbed while withdrawing money from a cash machine, we examined the effects of partial retrieval on the most relevant aspects of the event: actions (Experiment 1) and offender characteristics (Experiment 2), in both immediate and long‐term recall (24 hours). In both experiments long‐term recall was a replica of immediate recall for correct information as well as errors. The effects of partial retrieval practice were also repeated in long‐term recall. Conventional RIF was found for offender characteristics but selective retrieval of the actions of the event produced no comparable effect. It is assumed that the organisation and integration of the actions of the event protected them from RIF. Copyright © 2006 John Wiley & Sons, Ltd.     

The hippocampus, space, and viewpoints in episodic memory

A computational model of how single neurons in and around the rat hippocampus support spatial navigation is reviewed. The extension of this model, to include the retrieval from human long-term memory of spatial scenes and the spatial context of events is discussed. The model explores the link between spatial and mnemonic functions by supposing that retrieval of spatial information from long-term storage requires the imposition of a particular viewpoint. It is consistent with data relating to representational hemispatial neglect and the involvement of the mammillary bodies, anterior thalamus, and hippocampal formation in supporting both episodic recall and the representation of head direction. Some recent behavioural, neuropsychological, and functional neuroimaging experiments are reviewed, in which virtual reality is used to allow controlled study of navigation and memory for events set within a rich large-scale spatial context. These studies provide convergent evidence that the human hippocampus is involved in both tasks, with some lateralization of function (navigation on the right and episodic memory on the left). A further experiment indicates hippocampal involvement in retrieval of spatial information from a shifted viewpoint. I speculate that the hippocampal role in episodic recollection relates to its ability to represent a viewpoint moving within a spatial framework.     

Implicit associations and social anxiety

The aim of this study was to test whether an Implicit Association Test (IAT) with self- and social anxiety-words is sensitive to differences in trait social anxiety, and to an experimental induction of social anxiety. This was performed in the context of a partial replication of a previous study, in which Mauss et al. (2004) compared high and low trait socially anxious individuals before and after a social anxiety induction (an impromptu speech). Mauss et al.'s findings were replicated; that is, (i) the social anxiety induction produced increases in self-rated anxiety, self-rated physiological responses, and actual physiological arousal; and (ii) higher trait social anxiety was associated with stronger self-rated anxiety and stronger self-rated physiological responses, but not with stronger actual physiological responses. In addition, the results showed higher IAT social anxiety scores, both (i) as a result of the social anxiety induction, and (ii) as a function of self-reported trait social anxiety. It is suggested that the IAT may be a useful method for the experimental study of automatic evaluational thought patterns.     

The role of episodic and semantic memory in episodic foresight

In this paper we describe a special form of future thinking, termed “episodic foresight” and its relation with episodic and semantic memory. We outline the methodologies that have largely been developed in the last five years to assess this capacity in young children and non-human animals. Drawing on Tulving's definition of episodic and semantic memory, we provide a critical analysis of the role that both types of memory might have on the episodic foresight tasks described in the literature. We conclude by highlighting some unanswered questions and suggesting future directions for research that could further our understanding of how memory is intimately connected to episodic foresight.     

Role of environmental context in eyewitness memory

We investigated whether varying the environmental context will affect the magnitude of retroactive interference produced by misleading postevent information in an eyewitness memory paradigm. Previous eyewitness memory studies have typically presented the original and misleading information in the same environmental context. In this experiment, the physical contexts in which the original information and the misleading information were presented were varied, a procedure that is more analogous to what usually occurs in real world situations. We tested 288 subjects, half using the original and misleading information in the same encoding context and half using a different context for presenting the two types of information. Memory for the original event was assessed using either the standard recognition test procedure or the modified test developed by McCloskey and Zaragoza (1985). Measures of both recognition accuracy and response latency showed no difference in performance attributable to varying the environmental context. The present data replicate the findings of previous single-context experiments that showed the two recognition test procedures to produce different patterns of results. Thus, environmental context seems to play little role in determining the magnitude of the misleading postevent information effect.