The role of reminding in long-term memory for temporal order

Order codes are one of the three main types of information that have been hypothesized to underlie memory for the times of life events. Published evidence for the theory, however, has come exclusively from research in which brief retention intervals have been used. In the first of two studies, 101 adults judged the order of pairs of movies released 5-14 years ago, half of which shared a common major actor. There was no evidence that related films could be ordered more accurately than unrelated ones. In the second study, 88 students were presented with in-class announcements that were either related or unrelated to an earlier announcement. Three weeks later,they judged the order of the pairs of announcements. There was no difference between the accuracy for the related and the unrelated pairs. The findings do not support the proposal that the automatic creation of order information at the time of encoding contributes to autobiographical memory.     

The role of response inhibition in temporal preparation: Evidence from a go/no-go task

During the foreperiod (FP) of a warned reaction task, participants engage in a process of temporal preparation to speed response to the impending target stimulus. Previous neurophysiological studies have shown that inhibition is applied during FP to prevent premature response. Previous behavioral studies have shown that the duration of FP on both the current and the preceding trial codetermine response time to the target. Integrating these findings, the present study tested the hypothesis that the behavioral effects find their origin in response inhibition on the preceding trial. In two experiments the variable-FP paradigm was combined with a go/no-go task, in which no-go stimuli required explicit response inhibition. The resulting data pattern revealed sequential effects of both FP (long or short) and response requirement (go or no-go), which could be jointly understood as expressions of response inhibition, consistent with the hypothesis.     

Modulation of long-term memory by arousal in alexithymia: The role of interpretation

Moderate physiological or emotional arousal induced after learning modulates memory consolidation, helping to distinguish important memories from trivial ones. Yet, the contribution of subjective awareness or interpretation of arousal to this effect is uncertain. Alexithymia, which is an inability to describe or identify one’s emotional and arousal states even though physiological responses to arousal are intact, provides a tool to evaluate the role of arousal interpretation. Participants scoring high and low on alexithymia (N = 30 each) learned a list of 30 words, followed by immediate recall. Participants then saw either an arousing (oral surgery) or neutral video (tooth brushing). Memory was tested 24-h later. Physiological response to arousal was comparable between groups, but subjective response to arousal was impaired in high alexithymia. Yet, delayed word recognition was enhanced by arousal regardless of alexithymia status. Thus, subjective response to arousal, i.e., cognitive appraisal, was not necessary for memory modulation to occur.     

Knowing which day of the week it is: temporal structure and dynamics of memory

The complementary role of static and dynamic information used when one needs to be located in time was studied. Static information refers to temporal knowledge about days of the week, and dynamic information reflects a sense of time, taking into account the present, the near past, and the future. Each day of an actual 7-day wk., 699 women and 620 men were asked to provide a "right" or "wrong" response to a statement such as "Today is X," where X was the name of one of the seven days of the week. Analysis suggested use of a structured temporal representation of the week: the weekend, a landmark, had an anchoring role. Also the dynamics of the content of working memory were indicated. The active "temporal window" participants hold in mind seems directed more towards the future than the past. Results are discussed within the more general context of time management.     

Working memory, long-term memory, and medial temporal lobe function

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have been interpreted to mean that the MTL is sometimes needed for working memory and possibly even for visual perception itself. We present a reappraisal of this interpretation. Our main conclusion is that, if the material to be learned exceeds working memory capacity, if the material is difficult to rehearse, or if attention is diverted, performance depends on long-term memory even when the retention interval is brief. This fundamental notion is better captured by the terms subspan memory and supraspan memory than by the terms short-term memory and long-term memory. We propose methods for determining when performance on short-delay tasks must depend on long-term (supraspan) memory and suggest that MTL lesions impair performance only when immediate memory and working memory are insufficient to support performance. In neuroimaging studies, MTL activity during encoding is influenced by the memory load and correlates positively with long-term retention of the material that was presented. The most parsimonious and consistent interpretation of all the data is that subspan memoranda are supported by immediate memory and working memory and are independent of the MTL.     

Complexity effects in visuo-spatial working memory: Implications for the role of long-term memory

Several studies have shown that the capacity of visuo-spatial working memory is limited by complexity. Using a variant of the Corsi blocks task, this paper investigates the effect of complexity of the to-beremembered path on visuo-spatial memory span. Redundancy was determined by three Gestalt principles: symmetry, repetition, and continuation. Experiment 1 revealed an effect of path complexity. The subsequent experiments explored whether the superiority for recall of structured over complex paths can be attributed solely to the operation of visuo-spatial working memory, or whether it also reflects the use of long-term knowledge. Experiment 2 demonstrated that the effect of complexity remained, even when the mechanisms for visuo-spatial coding were removed by a secondary visuo-spatial task. In Experiments 3 and 4 subjects were trained in the recall of complex paths. This led to the creation of long-term memory representations for these paths, as shown by an improvement in their span, and a concomitant lack of transfer to new paths. Finally, Experiment 5 showed that one prior repetition of a complex path was sufficient to produce specific and long-term learning effects. These results point to the involvement of long-term memory processes in the temporary retention of visuo-spatial material for which representations exist in long-term memory. They also suggest that the effect of complexity may provide a tractable technique for investigating the mechanisms underlying the limits of visuo-spatial short-term storage.     

Complexity effects in visuo-spatial working memory: implications for the role of long-term memory

Several studies have shown that the capacity of visuo-spatial working memory is limited by complexity. Using a variant of the Corsi blocks task, this paper investigates the effect of complexity of the to-be-remembered path on visuo-spatial memory span. Redundancy was determined by three Gestalt principles: symmetry, repetition, and continuation. Experiment 1 revealed an effect of path complexity. The subsequent experiments explored whether the superiority for recall of structured over complex paths can be attributed solely to the operation of visuo-spatial working memory, or whether it also reflects the use of long-term knowledge. Experiment 2 demonstrated that the effect of complexity remained, even when the mechanisms for visuo-spatial coding were removed by a secondary visuo-spatial task. In Experiments 3 and 4 subjects were trained in the recall of complex paths. This led to the creation of long-term memory representations for these paths, as shown by an improvement in their span, and a concomitant lack of transfer to new paths. Finally, Experiment 5 showed that one prior repetition of a complex path was sufficient to produce specific and long-term learning effects. These results point to the involvement of long-term memory processes in the temporary retention of visuo-spatial material for which representations exist in long-term memory. They also suggest that the effect of complexity may provide a tractable technique for investigating the mechanisms underlying the limits of visuo-spatial short-term storage.     

Single-trial free recall from temporal search sets in long-term memory

The notion that the primacy effect, which is found in single-trial free-recall experiments, is partly a function of a selective-search component (Shiffrin, 1970) is contingent upon the ability of subjects to retrieve information via a distinctive temporal cue. The beginning of a list may be such a cue which defines a restricted temporal search set within a list as a whole. To test this theory, a second list-half primacy effect was generated in some 26 “unrelated” words lists by associating one color with each word in the first list half and another color with each word in the second list half. As predicted by the two-process theory, retrieval of the words which were presented around the color shift was differentially facilitated as measured by the difference between the probabilities of recall and recognition at each serial position and as compared to that of lists where the color codes were randomly presented.

     

Dissociation of short- and long-term face memory: evidence from long-term recency effects in temporal lobe epilepsy

We tested whether memory deficits in temporal lobe epilepsy (TLE) are better described by a single- or dual-store memory model. To this aim, we analyzed the influence of TLE and proactive interference (PI) on immediate and 24-h long-term recency effects during face recognition in 16 healthy participants and 18 right and 21 left non-surgical TLE patients. PI in healthy participants or TLE erased the long-term recency effect, but left the immediate recency effect unaffected. Although the immediate recency effect was still visible in right TLE patients, the number of detected recency items during immediate recognition was decreased in right TLE compared to left TLE. Right TLE was also related to decreased detection of pre-recency items during delayed recognition compared to left TLE, and decreased detection of pre-recency items during immediate recognition under PI. The results show that the temporal lobes are necessary for the long-term recency effect, but not for the immediate recency effect, and thus speak for a dissociation of short- and long-term memory for faces. Right TLE is related to more severe long-term memory deficits than left TLE and is also related to additional short-term memory deficits for faces.     

Language familiarity effects in short-term memory: The role of output delay and long-term knowledge

Four experiments examined the origins of language familiarity effects in bilingual short-term recall. In Experiments 1A and 1B, bilingual adults were tested on serial recall and probed serial recall of words and nonwords in their first and second languages. A first-language advantage was obtained on both measures, indicating that the beneficial effects of language familiarity are not exclusively attributable to lesser output delay during overt recall. In Experiments 2A and 2B, the same group of bilinguals was tested on serial recall and serial recognition of word lists in both languages. Although a sizeable first-language advantage was obtained on the serial recall measure, recognition performance was comparable in the two languages. On the basis of these results it is suggested that language differences in bilingual immediate memory arise in large part as a consequence of the differential availability of language-specific long-term knowledge with which to support retrieval processes in serial recall.     

Working memory capacity and retrieval from long-term memory: the role of controlled search

In two experiments, the role of working memory capacity (WMC) in the controlled search of long-term memory was examined. Participants performed a prolonged category fluency task that required them to retrieve as many animals as possible in 5 min. The results suggested that WMC differences arose in the numbers of animals retrieved, the numbers of clusters retrieved, and the rates of the retrieval (Exp. 1). However, no differences were found in terms of how participants initiated retrieval or in the nature of the clusters generated. Furthermore, an examination of differences in retrieval strategies suggested that high-WMC individuals were more strategic than low-WMC individuals and that these differences in retrieval strategies accounted for the overall differences in the numbers of animals retrieved. Additionally, presenting participants with retrieval cues eliminated WMC differences in the numbers of animals retrieved (Exp. 2). These results suggest that low-WMC individuals are less able than high-WMC individuals to select and utilize appropriate retrieval strategies to self-generate cues to access information in long-term memory. Collectively, the results are consistent with research suggesting that WMC is important for controlled search from long-term memory.     

The role of long-term familiarity and attentional maintenance in short-term memory for timbre

We study short-term recognition of timbre using familiar recorded tones from acoustic instruments and unfamiliar transformed tones that do not readily evoke sound-source categories. Participants indicated whether the timbre of a probe sound matched with one of three previously presented sounds (item recognition). In Exp. 1, musicians better recognised familiar acoustic compared to unfamiliar synthetic sounds, and this advantage was particularly large in the medial serial position. There was a strong correlation between correct rejection rate and the mean perceptual dissimilarity of the probe to the tones from the sequence. Exp. 2 compared musicians' and non-musicians' performance with concurrent articulatory suppression, visual interference, and with a silent control condition. Both suppression tasks disrupted performance by a similar margin, regardless of musical training of participants or type of sounds. Our results suggest that familiarity with sound source categories and attention play important roles in short-term memory for timbre, which rules out accounts solely based on sensory persistence.     

Scene memory is more detailed than you think: the role of categories in visual long-term memory

Observers can store thousands of object images in visual long-term memory with high fidelity, but the fidelity of scene representations in long-term memory is not known. Here, we probed scene-representation fidelity by varying the number of studied exemplars in different scene categories and testing memory using exemplar-level foils. Observers viewed thousands of scenes over 5.5 hr and then completed a series of forced-choice tests. Memory performance was high, even with up to 64 scenes from the same category in memory. Moreover, there was only a 2% decrease in accuracy for each doubling of the number of studied scene exemplars. Surprisingly, this degree of categorical interference was similar to the degree previously demonstrated for object memory. Thus, although scenes have often been defined as a superset of objects, our results suggest that scenes and objects may be entities at a similar level of abstraction in visual long-term memory.     

Working memory retention systems: a state of activated long-term memory

High temporal resolution event-related brain potential and electroencephalographic coherence studies of the neural substrate of short-term storage in working memory indicate that the sustained coactivation of both prefrontal cortex and the posterior cortical systems that participate in the initial perception and comprehension of the retained information are involved in its storage. These studies further show that short-term storage mechanisms involve an increase in neural synchrony between prefrontal cortex and posterior cortex and the enhanced activation of long-term memory representations of material held in short-term memory. This activation begins during the encoding/comprehension phase and evidently is prolonged into the retention phase by attentional drive from prefrontal cortex control systems. A parsimonious interpretation of these findings is that the long-term memory systems associated with the posterior cortical processors provide the necessary representational basis for working memory, with the property of short-term memory decay being primarily due to the posterior system. In this view, there is no reason to posit specialized neural systems whose functions are limited to those of short-term storage buffers. Prefrontal cortex provides the attentional pointer system for maintaining activation in the appropriate posterior processing systems. Short-term memory capacity and phenomena such as displacement of information in short-term memory are determined by limitations on the number of pointers that can be sustained by the prefrontal control systems.     

The modality effect in long-term memory: a test of the echoic-consolidation hypothesis

Thirty-four subjects performed a task which combined the running memory and ‘throughlist’ distractor paradigms and was designed to permit an echoic consolidation effect across all serial positions , The predicted long-term difference between reading aloud and reading silently was clearly demonstrated and the results were used to argue in support of the ‘indirect-echoic’ hypothesis.     

The temporal dynamics of retention of a context memory: something is missing

We use a variation of contextual fear conditioning, called the context pre-exposure facilitation effect (CPFE) to study the rat's memory for context. In this paradigm, the rat is pre-exposed to a conditioning context and later returned to that context, where it is immediately shocked. The memory context is revealed by the fact that pre-exposure to the conditioning context, but not to a different context, greatly enhances conditioned fear produced by immediate shock. We report that rat's retention of the context memory is a nonmonotonic U-shaped function of the interval separating pre-exposure and immediate shock. Retention performance decays rapidly so that within 2 min of pre-exposure there is no evidence that the rat was pre-exposed to the context. Within a few hours, however, a strong CPFE was observed that persisted for at least 28 d. Two hypotheses are discussed: (1) the descending arm of the U represents a retrieval failure, and (2) the U-shaped function represents two discontinuous memory processes initiated in parallel-short-term synaptic changes that are rapidly initiated, but also decay rapidly, and long-term synaptic processes that take time to generate but can endure for days.     

The temporal orientation of memory: It's time for a change of direction

Common wisdom, philosophical analysis and psychological research share the view that memory is subjectively positioned toward the past: specifically, memory enables one to become re-acquainted with the objects and events of his or her past. In this paper I call this assumption into question. As I hope to show, memory has been designed by natural selection not to relive the past, but rather to anticipate and plan for future contingencies – a decidedly future-oriented mode of subjective temporality. This is not to say memory makes no reference to the past. But, I argue, past-oriented subjectivity is a by-product of a system designed by natural selection to help us face and respond to the “now and the next”. I discuss the implications of the proposed temporal realignment for research agendas as well as the potential limitations of measures designed to explore memory by focusing on its retentive capabilities.     

The personalisation method applied to a working memory task: Evidence of long-term working memory effects

Ericsson and Kintsch (1995) proposed that, in situations of expertise, individuals can overcome working memory limitations by using long-term working memory. It allows a greater capacity than working memory thanks to long-term memory encoding and retrieving. To test this characteristic, an adaptation of Daneman and Carpenter's (1980) reading span was used. To operationalise expertise, the personalisation method (Guida & Tardieu, 2005) was employed. In Experiment 1, a personalised group, which read reading span sentences that mentioned familiar locations, was compared to a nonpersonalised group, which read sentences with unfamiliar locations. In Experiment 2, a personalised group, which read reading span sentences with neutral locations, was encouraged to mentally personalise these locations by thinking about known locations. This group was compared to a nonpersonalised group, which was encouraged to think about unknown locations. The personalised groups were expected to store and retrieve information in long-term memory via long-term working memory more easily than the nonpersonalised groups, which had to count massively on working memory. The results showed that personalisation enhanced reading span and confirmed one implication of the long-term working memory theory: high- and low-reading-span differences could also be due to long-term memory retrieval. Finally, these results are interpreted in terms of interaction between working memory size and long-term memory knowledge, showing that participants with a lower reading span benefited more from high domain knowledge than participants with a higher reading span.     

Relating action to abstract goals increases physical activity reported a week later

ObjectiveThe primary aim of the present study was to investigate whether construing action abstractly versus concretely increases physical activity over a one-week period.Design and methodAn experimental study was conducted in which participants were asked to commit to engaging in physical activity at least four times in the coming week. After making this commitment, participants were assigned randomly to think about the concrete procedures or the abstract purpose of their actions. Additionally, in an attempt to induce differences in level of goal conflict, participants were assigned randomly to receive a reminder of a different or consistent goal. The main outcome variable of interest was the number of minutes spent on physical activity over the following 7-day period.ResultsConsistent with the hypothesis, participants in the abstract condition reported engaging in significantly more minutes of physical activity than did those in the concrete condition. Level of goal conflict did not significantly impact physical activity. The effect of abstract versus concrete thinking on physical activity also was related to the processing of negative affect.ConclusionBy providing evidence that construing action abstractly impacts physical activity, the present investigation makes an important addition to research aiming to identify effective means of increasing physical activity.     

The relationship of novelty preferences during infancy to later intelligence and later recognition memory

In the present study, a group of children originally tested for visual novelty preferences at 7 months and seen for estimates of intelligence at 3 years were revisited and tested for intellectual functioning and for visual recognition performance at 5 years. Prediction from performance at 7 months to intellectual functioning at 5 years was significant and remained at the same level as prediction from 7 months to 3 years (r = .42 at each point). In addition, it was shown that data on early novelty preferences could be combined with information on birth-order and parental education to achieve good prediction (R = .65) of five-year IQ scores. A further goal of the present study was to discover if infants' preferences for visual novelty, assumed to be an early measure of visual recognition memory would be more highly associated with later visual recognition performance or with later intellectual level. The results indicate that novelty preferences were more highly related to later intelligence quotients than to later recognition performance and such a pattern of relationships did not to be artificial.