Memory & Cognition最新文献

Because segments in fluent speech (e.g., words and phrases) are not reliably separated by pauses, a key task when listening to an unfamiliar language is to parse the incoming speech into segments to be learned. We aim to understand how working memory contributes to that segmentation learning. One cue to segmentation occurs when a segment is repeated in varying contexts. Cowan (Acta Psychologica, 77(2), 121-135, 1991) explored a language analog to study how segmentation occurs during immediate memory of speech, and found effects of segment presentation frequency, stimulus length, and serial position. Here we ask whether those effects extend from working memory to long-term memory. Overlapping segments were presented (e.g., mah bar slo mi and slo mi geh), varying numbers of times (presentation frequencies) to determine how varying the schedule of repetition patterns would affect perception of a unified test pattern formed from the two of them (e.g., mah bar slo mi geh). These constructions provide an analogy to how segments occur in varying contexts in speech. Participants were to indicate where they heard the boundaries between syllables. In immediate memory, the perceived boundaries more often reflected the most frequently presented pattern, and often reflected both pattern boundaries (in this example, mah bar / slo mi / geh). In a long-term memory follow-up, however, the original presentation frequencies only mattered for certain short test pattern configurations. We suggest that working memory for speech, without a semantic component, may be an incomplete basis to learn longer segments in an unfamiliar language.

Attentional refreshing has been described as an attention-based, domain-general maintenance mechanism in working memory. It is thought to operate via focusing executive attention on information held in working memory, protecting it from temporal decay and interference. Although attentional refreshing has attracted a lot of research, its functioning is still debated. At least one conception of refreshing supposes that it relies on semantic long-term memory representations to reconstruct working memory traces. Although investigations in the verbal domain found evidence against this hypothesis, a different pattern could emerge in visuospatial working memory in which absence of refreshing evidence has been observed for stimuli with minimal associated long-term knowledge. In a series of four experiments, the current study investigated the hypothesis of an involvement of semantic long-term representations in the functioning of attentional refreshing in the visuospatial domain. Both cognitive and memory load effects have been proposed as indexes of attentional refreshing. Therefore, we investigated the interaction between the effects of visual familiarity (a long-term memory effect) and cognitive load on recall performance (Experiments 1A and 1B), as well as the interaction between the effects of visual familiarity and memory load on the response times in a concurrent processing task (Experiments 2A and 2B). Results were consistent across experiments and go against the hypothesis of the involvement of semantic long-term memory in the functioning of attentional refreshing in visuospatial working memory. As such, this study corroborates the results found in the verbal domain. Implications for attentional refreshing and working memory are discussed.

Studies on the SPoARC effect have shown that serial information is spatially processed in working memory. However, it remains unknown whether these spatial-positional associations are durable or only temporary. This study aimed at investigating whether spatialization would persist when a sequence presented repeatedly is expected to be chunked. If chunked, the items could be unified spatially and their spatialization could vanish. Thirty-seven participants performed a spatialization task which was remotely inspired by the Hebb repetition paradigm. A sequence of four stimuli presented individually in the middle of a computer screen was repeated throughout the task. After each sequence, participants had to decide whether a probe belonged to the series using two lateralized response keys. The results showed no spatialization for these repetitive sequences, on average. Moreover, further analysis revealed that the effect was detectable at the beginning of the task, suggesting that the more the sequence was repeated, the less participants spatialized information from left to right. These findings show that associations created in working memory between items and space can vanish in repeated sequences: we discuss the idea that working memory progressively saves on spatialization once a sequence is chunked in long-term memory.

Individual differences in working memory capacity (WMC) are correlated with long-term memory (LTM) differences. Whether this is because high-WMC individuals encode more effectively, resulting in better LTM storage, or because they better retrieve information from LTM is debated. In two experiments, we used Bayesian-hierarchical multinomial modeling to correlate participant-level storage and retrieval processes from LTM recall to WMC abilities estimated from operation and symmetry complex span tasks. In Experiment 1, we presented participants with 20 consecutive words, including semantically associated pairs (e.g., knife and fork), to assess LTM processes. Participants received standard (n = 242) or associative-storage instructions (n = 222) and then completed a free recall task. In Experiment 2, we instructed participants (N = 239) to memorize 40 cue-target words as pairs before completing free and cued recall tasks. Correlations with WMC emerged with storage and retrieval processes and only when an associative storage strategy was instructed (Experiment 1). When associative processing was inherent to the task (Experiment 2), only the associative storage, not the retrieval advantage, replicated. The strategy reports suggest that high-WMC individuals use associative encoding strategies more effectively, resulting in better storage in LTM.

Transitive inference (TI), referring to one's ability to learn that if A > B and B > C, one can infer that A > C, is a form of serial learning that has been tested using a variety of experimental protocols. An element of most of these protocols is the presentation of some form of visual corrective feedback to help inform naïve participants about the nature of the task. Therefore, corrective feedback is often used as a critical tool for experimental TI. To further explore this tool, we presented varying forms/presence of visual feedback during TI performance: corrective, none, and ambiguous. Of the three conditions, presentation of the ambiguous feedback yielded the clearest disruption of TI performance, obvious in measurements of both response accuracy and reaction times. Participants appears to remain engaged with feedback was withheld entirely, but to disengage when presented with ambiguous feedback. Therefore, the choice regarding the form of feedback provided during testing may be critical for information processing of inferences.

The episodic flanker task is an episodic version of the Eriksen and Eriksen (Perception & Psychophysics, 16 (1), 143-149, 1974) perceptual flanker task, showing the same compatibility and distance effects. Subjects are presented with a list followed by a probe display in which one item is cued. The task, to indicate whether the probed letter appeared in the same position in the memory list, requires focusing attention on a single item in memory. The probe display contains flanking items to be ignored. They are same as the memory list or different. Same flankers are compatible with "yes" responses and incompatible with "no" responses. Different flankers are incompatible with "yes" responses and compatible with "no" responses. Previously, we presented multiple flankers in the probe, allowing a global matching strategy. Here, we report two episodic flanker experiments with just one flanker in the probe to encourage focusing sharply on the target. We found flanker compatibility effects in both experiments when a single flanker appeared immediately adjacent to the target. Experiment 2 varied the distance between the flanker and the target in the probe and the memory list and found the compatibility effect in response time only when the flanker was immediately adjacent to the target in both the probe and the memory list. The effect in accuracy also appeared when the flanker was two positions away in both the probe and the memory list. These results show that attention is focused sharply on elements of a memory structure during retrieval, suggesting that memory retrieval is perceptual attention turned inward.

Visual working memory is thought to have a fixed capacity limit. However, recent evidence suggests that a greater number of real-world objects than simple features (i.e., colors) can be maintained, an effect termed the object benefit. Here, we examined whether this object benefit in visual working memory is due to qualitatively different memory processes employed for meaningful stimuli compared to simple features. In online samples of young adults, real-world objects were better remembered than colors, had higher measures of recollection, and showed a greater proportion of high-confidence responses (Exp. 1). Objects were also remembered better than their scrambled counterparts (Exp. 2), suggesting that this benefit is related to semantic information, rather than visual complexity. Critically, the specific objects that were likely to be remembered with high confidence were highly correlated across experiments, consistent with the idea that some objects are more memorable than others. Visual working memory performance for the least-memorable objects was worse than that of colors and scrambled objects. These findings suggest that real-world objects give rise to recollective, or at least high-confidence, responses at retrieval that may depend on activation of semantic features, but that this effect is limited to certain objects.

While humans often encode and retrieve memories in groups, the bulk of our knowledge of human memory comes from paradigms with individuals in isolation. The primary phenomenon of interest within the relatively new field of collaborative memory is collaborative inhibition: the tendency for collaborative groups to underperform in free recall tasks compared with noncollaborative groups of the same size. This effect has been found in a variety of materials and group compositions. However, most research in this field is led by verbal conceptual theories without guidance from formal computational models. We present a framework to scale the Search of Associative Memory model (SAM) to collaborative free recall paradigms with multiple models working together. Multiple SAM models recalling together naturally produce collaborative inhibition when the group members use recalls by the group as cues to retrieve from memory, strongly supporting the "retrieval disruption" hypothesis. This work shows that SAM can act as a unified theory to explain both individual and collaborative memory effects and offers a framework for future predictions of scaling to increased group sizes, shared knowledge, and factors facilitating the spread of false memories in groups.

Two experiments investigated proactive facilitation (PF) or proactive interference (PI) in the recall of recently learned targets, under conditions of assessing the detection and recollection of target changes across two learning phases (with A-B/A-D word pairs). Some changes established meaningful connections across the phases; others did not. Task instructions on the subsequent cued-recall test (Experiment 1) or during Phase 2 study (Experiment 2) guided participants (university students) to monitor and report the changes. Accuracy in cued recall conditionalized on measures of change awareness replicated previous findings in establishing conditions for PF and PI. However, PF was much reduced for unconnected materials. Moreover, when change recollection failed, PI occurred even under conditions of meaningful connections (Experiment 1). Discussion emphasizes this interdependence of meaningfulness of connections and change awareness in influencing whether and how memory for earlier events affects memory for more recent ones.

When faced with requests for information ("Where did you go last night?"), why do speakers make non-sentential replies ("The movies") rather than full sentence replies ("I went to the movies")? We examine the role that pragmatic factors (politeness and formality) and memory factors (the speaker's ability to retrieve the answer to the question) play in determining whether speakers generate a non-sentential reply. Participants answered a series of questions about their lives. Pragmatic factors affected the participants' responses. Speakers instructed to be polite or formal made fewer non-sentential replies than speakers who did not receive specific instructions. Memory retrieval (indexed both by the time required for the participant to begin their response and by the presence of disfluencies at the beginning of the response) did not have a straightforward relationship to the production of non-sentential replies. The effect of response latency and disfluencies depended on whether the participants were told to be polite or formal (or if they were given no instruction at all).