Spreading the words: A spacing effect in vocabulary learning

The spacing effect refers to the frequently observed finding that distributing learning across time leads to better retention than massing it into one single study session. In the present study, we examined whether the spacing effect generalises to primary school vocabulary learning. To this aim, children from Grade 3 were taught the meaning of 15 new words using a massed procedure and 15 other new words using a spaced procedure. The 15 words in the massed condition were divided into three sets of five words, and each set was taught three times in one of three learning sessions. In the spaced condition, learning was distributed across the three sessions: All 15 words were practised once in each of the three learning sessions. At the retention tests after 1 week and after 5 weeks we observed that the meaning of spaced words was remembered better than the meaning of massed words.     

Unblocking memory through directed forgetting

The ability to remember an item can be blocked, or negatively primed, by exposure to related items. For example, ALLERGY is less likely to be generated given the word fragment A_L_ _GY if one is first exposed to ANALOGY. We examined whether this memory blocking effect is influenced by list-method directed forgetting. A total of 144 participants learned two lists of items, each consisting of words that were designed to negatively prime performance on a subsequent word fragment completion task. Participants who were told to forget List 1 before learning List 2 suffered significantly less memory blocking owing to the negative primes from List 1 than participants who were told to remember List 1. These results suggest that directed forgetting can modify the memory blocking effect by affecting the accessibility of information in memory.     

JAM-boree: An application of observation oriented modelling to judgements of associative memory

Null hypothesis significance testing is criticised for emphatically focusing on using the appropriate statistic for the data and an overwhelming concern with low p-values. Here, we present a new technique, Observation Oriented Modeling (OOM), as an alternative to traditional techniques in the social sciences. Ten experiments on judgements of associative memory (JAM) were analysed with OOM to show data analysis procedures and the consistency of JAM results across several types of experimental manipulations. In a typical JAM task, participants are asked to rate the frequency of word pairings, such as LOST-FOUND, and are then compared to actual normed associative frequencies to measure how accurately participants can judge word pairs. Three types of JAM tasks are outlined (traditional, paired, and instructional manipulations) to demonstrate how modelling complex hypotheses can be applied through OOM to this type of data that would be conventionally analysed with null hypothesis significance testing.     

The face of an angel: Effect of exposure to details of moral behavior on facial recognition memory

The Dangerous Decisions Theory (DDT; Porter & ten Brinke, 2009) posits that instantaneous perceptions of trustworthiness based on a stranger's face influence the manner in which ensuing information about the target is processed. This study tested a bi-directional DDT model, proposing that information concerning a target's moral behavior could distort eyewitness memory for the individual's facial trustworthiness. Participants (N = 141) viewed a target individual's face (previously rated as appearing “neutral” on trustworthiness) and then were exposed to one of the three vignettes describing the target's behavior (either immoral, morally neutral, or altruistic). Following a delay, observers were asked to identify the target individual on a facial morph video (continuously ranging in levels of perceived trustworthiness). Results indicated that behavioral information varying in morality influenced facial recognition memory; specifically, faces were recalled as having less trustworthy features following a disclosure of immoral/criminal behavior.     

Suggestibility effects persist after one year in children who experienced a single or repeated event

The study of long-term memory for repeated events has important implications for understanding autobiographical memory in a forensic context. Recall accuracy and suggestibility for details of an instance of a repeated event versus a single event were examined in children aged 5–6 and 7–8 years after a one-year delay. Children who reported an instance of a repeated event were more likely to report that a non-experienced detail had occurred and reported less correct information than did single-event children. After one year a significant suggestibility effect was still present. The present experiment provides further evidence for both the capabilities and limitations of children's long-term recall and reinforces the importance of non-suggestive interviews of children at all stages of investigation.     

Systemic and local administration of estradiol into the prefrontal cortex or hippocampus differentially alters working memory

The influence of estradiol on learning and memory is dependent on a number of factors. The effects of physiological levels of estradiol on the acquisition of a spatial working memory task mediated by the prefrontal cortex (PFC) and the hippocampus were examined in Experiment 1. Ovariectomized Long-Evans rats received daily injections of estradiol or vehicle were tested on the win-shift version of the radial arm maze. A high dose of estradiol benzoate (5 microg) enhanced acquisition of the task, whereas a low dose of estradiol (0.3 microg) increased the number of errors committed over 17 days of testing. Experiment 2 was conducted to examine site-specific influences of estradiol on spatial working memory in well-trained rats. Saline and estradiol cyclodextrin (0.1 and 0.9 microg) were infused into the prelimbic region of the PFC or dorsal hippocampus 40 min prior to testing on the win-shift task. Infusions of estradiol into both brain areas attenuated saline-infusion disruptions in working memory. Specifically, the higher dose of estradiol facilitated working memory when infused into the PFC, whereas the lower dose of estradiol facilitated performance when infused into the dorsal hippocampus. Moreover, working memory was significantly impaired 24 h after infusions of estradiol into the dorsal hippocampus but not the PFC. These data provide further evidence for the notion that estradiol can dose-dependently alter memory processes and suggest that facilitation or disruptions of working memory by estradiol are site- and time-specific.     

A comparison of flashbacks and ordinary autobiographical memories of trauma: content and language

We investigated hypotheses derived from the dual representation theory of posttraumatic stress disorder, which proposes that flashbacks and ordinary memories of trauma are supported by different types of representation. Sixty-two participants meeting diagnostic criteria for posttraumatic stress disorder completed a detailed written trauma narrative, and afterwards identified those sections in the narrative that had been written in flashback and ordinary memory periods. As predicted, flashback periods were characterised by greater use of detail, particularly perceptual detail, by more mentions of death, more use of the present tense, and more mention of fear, helplessness, and horror. In contrast, ordinary memory sections were characterised by more mention of secondary emotions such as guilt and anger.     

Trauma and autobiographical memory specificity in depressed inpatients

Research on autobiographical memory has shown that clinical depression is associated with a difficulty in retrieving specific autobiographical memories in response to cue words. This study examined the relation between lack of autobiographical memory specificity and self-reported trauma in a group of depressed adults (N = 23). In addition to the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986) participants completed a number of questionnaires assessing the presence of traumatic experiences in the past, level of depression and neuroticism. The number of specific responses was not related to depression severity, but was significantly associated with the presence and severity of reported physical abuse. Participants who had been victim of physical abuse were less specific than participants who had not been confronted with such physical adversities. The results are discussed in the context of a functional hypothesis about the developmental relations between memory specificity, trauma and depression.     

Uncovering the structure of a memorist's superior "basic" memory capacity

After extensive laboratory testing of the famous memorist Rajan, Thompson, Cowan, and Frieman (1993) proposed that he was innately endowed with a superior memory capacity for digits and letters and thus violated the hypothesis that exceptional memory fully reflects acquired "skilled memory." We successfully replicated the empirical phenomena that led them to their conclusions. From additional analyses and new experiments, we found support for an alternative hypothesis, namely that Rajan's superior memory for digits was mediated by learned encoding techniques that he acquired during nearly a thousand hours of practice memorizing the mathematical constant pi. Our paper describes a general experimental approach for studying the structure of exceptional memory and how Rajan's unique structure is consistent with the general theoretical framework of long-term working memory (Ericsson and Kintsch, 1995).     

"It's magic!" The effects of presentation modality on children's event memory, suggestibility, and confidence judgments

The current study investigated the influence of presentation modality (live, video, and slide show) on children's memory, suggestibility, recognition, and metamemorial monitoring processes. A total of 270 children in three age groups (5- and 6-year-olds, 7- and 8-year-olds, and 9- and 10-year-olds) watched a magic show and were questioned about it 1 week later. The live show yielded more correct answers to nonleading questions, higher resistance to misleading questions, and better recognition memory than did the video condition, which in turn resulted in better performance than did the slide show. Although presentation modality raised the general level of memory performance, the effects were equally strong in all age groups and did not affect memory phenomena such as the size of the misinformation effect and confidence judgments.