Investigating the influence of continuous babble on auditory short-term memory performance

A number of factors could explain the adverse effect that babble noise has on memory for spoken words (Murphy, Craik, Li, & Schneider, 2000 Murphy, D. R., Craik, F. I. M., Li, K. Z. H. and Schneider, B. A. 2000. Comparing the effects of aging and background noise on short-term memory performance. Psychology and Aging, 15: 323–334. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Babble could degrade the perceptual representation of words to such an extent that it compromises their subsequent processing, or the presence of speech noise in the period between word presentations could interfere with rehearsal. Thirdly, the top-down processes needed to extract the words from the babble could draw on resources that otherwise would be used for encoding. We tested all these hypotheses by presenting babble either only during word presentation or rehearsal, or by gating the babble on and off 500 ms before and after each word pair. Only the last condition led to a decline in memory. We propose that this decline in memory occurred because participants were focusing their attention on the auditory stream (to enable them to better segregate the words from the noise background) rather than on remembering the words they had heard. To further support our claim we show that a similar memory deficit results when participants perform the same memory task in quiet together with a nonauditory attention-demanding secondary task.     

情绪一致性对有意遗忘的影响

有意遗忘是强调遗忘的有意性和指向性。对负性情绪的有意遗忘有利于个体的身心健康。本研究采用单字范式,实验一以正性、负性和中性情绪词为材料,探讨了情绪材料对有意遗忘的影响。结果发现,三类词语均表现出了显著的有意遗忘效应;实验二在实验一的基础上加入了情绪状态,探讨了情绪状态和情绪材料对有意遗忘的影响,结果发现,在积极情绪状态下,被试更多地遗忘负性情绪词;在消极情绪状态下,被试更多地遗忘中性词。表明个体对情绪信息的有意遗忘既受信息的情绪性影响,又受个体情绪状态的影响。     

Elucidating the effects of ageing on remembering perceptually distorted word pairs

We investigated the effects of age, background babble, and acoustic distortion of the word itself on serial position memory in a series of experiments involving six different auditory environments (quiet, and 12-talker background babble presented between, overlapping, or concurrent with word presentation or with two kinds of distortion applied to the words). To control for hearing, the level of babble or distortion was adjusted so that younger and older adults could hear the words equally well. Although the presence of continuous and word-flanking background babble adversely affected memory in the early serial positions in both age groups, only older adults' memory was adversely affected in the later serial positions. Moreover, younger adults' memory was not affected by acoustic word distortion, whereas one of the two types of temporal distortion adversely affected memory for later serial positions in older adults. The exact pattern of impairment and its interaction with age suggests that memory in older adults is more affected than that in younger adults in complex listening situations because they either need more time or have to employ more attentional resources to segregate different auditory streams, thereby depleting the pool of resources available for memory encoding.     

How are pictures registered in memory?

Three experiments tested the hypothesis that pictorial memory is much less dependent on rehearsal than is verbal memory. Experiment I examined incidental learning since this is assumed to reflect learning with little or no rehearsal. Following a classification task, intentional and incidental learning for pictures and for words was compared. The superiority of pictorial memory was especially marked in incidental learning. Experiment II showed that this result was not due to differences in the amount of processing required to classify pictures and words. RTs to classify words and pictures did not differ, and incidental learning was again superior for pictures. In Experiment III rehearsal opportunity was restricted by a concurrent task during presentation of word and picture lists, and the decrement was very much greater for word learning than for picture learning. It was concluded that manipulation of rehearsal opportunity has relatively little effect on pictorial memory.     

Remember to blink: Reduced attentional blink following instructions to forget

This study used rapid serial visual presentation (RSVP) to determine whether, in an item-method directed forgetting task, study word processing ends earlier for forget words than for remember words. The critical manipulation required participants to monitor an RSVP stream of black nonsense strings in which a single blue word was embedded. The next item to follow the word was a string of red fs that instructed the participant to forget the word or green rs that instructed the participant to remember the word. After the memory instruction, a probe string of black xs or os appeared at postinstruction positions 1–8. Accuracy in reporting the identity of the probe string revealed an attenuated attentional blink following instructions to forget. A yes–no recognition task that followed the study trials confirmed a directed forgetting effect, with better recognition of remember words than forget words. Considered in the context of control conditions that required participants to commit either all or none of the study words to memory, the pattern of probe identification accuracy following the directed forgetting task argues that an intention to forget releases limited-capacity attentional resources sooner than an instruction to remember—despite participants needing to maintain an ongoing rehearsal set in both cases.     

Examining the relationship between free recall and immediate serial recall: the effect of concurrent task performance

In 3 experiments, participants saw lists of 16 words for free recall with or without a 6-digit immediate serial recall (ISR) task after each word. Free recall was performed under standard visual silent and spoken-aloud conditions (Experiment 1), overt rehearsal conditions (Experiment 2), and fixed rehearsal conditions (Experiment 3). The authors found that in each experiment, there was no effect of ISR on the magnitude of the recency effect, but interleaved ISR disrupted free recall of those words that would otherwise be rehearsed. The authors conclude that ISR and recency cannot both be outputs from a unitary limited-capacity short-term memory store and discuss the possibility that the process of rehearsal may be common to both tasks.     

Short-term retention of a single word relies on retrieval from long-term memory when both rehearsal and refreshing are disrupted

Many working memory (WM) models propose that the focus of attention (or primary memory) has a capacity limit of one to four items, and therefore, that performance on WM tasks involves retrieving some items from long-term (or secondary) memory (LTM). In the present study, we present evidence suggesting that recall of even one item on a WM task can involve retrieving it from LTM. The WM task required participants to make a deep (living/nonliving) or shallow (“e”/no “e”) level-of-processing (LOP) judgment on one word and to recall the word after a 10-s delay on each trial. During the delay, participants either rehearsed the word or performed an easy or a hard math task. When the to-be-remembered item could be rehearsed, recall was fast and accurate. When it was followed by a math task, recall was slower, error-prone, and benefited from a deeper LOP at encoding, especially for the hard math condition. The authors suggest that a covert-retrieval mechanism may have refreshed the item during easy math, and that the hard math condition shows that even a single item cannot be reliably held in WM during a sufficiently distracting task—therefore, recalling the item involved retrieving it from LTM. Additionally, performance on a final free recall (LTM) test was better for items recalled following math than following rehearsal, suggesting that initial recall following math involved elaborative retrieval from LTM, whereas rehearsal did not. The authors suggest that the extent to which performance on WM tasks involves retrieval from LTM depends on the amounts of disruption to both rehearsal and covert-retrieval/refreshing maintenance mechanisms.     

Aging and the Deletion Function of Inhibition

The present study was adapted from the sentence completion task of Hartman and Hasher (1991). We addressed the question raised by Burke (1997): are the age-related differences in priming effects found in that task better explained by deficits in explicit memory or by inefficient inhibitory mechanisms? In the study phase, older and younger adults read high cloze sentences ending with an expected or an unexpected final word. In the second phase, participants were asked to complete sentence frames with either the final word presented during the study phase (inclusion condition) or with another, new word (exclusion condition). The third phase was an indirect memory test of perceptual identification. Finally, we compared explicit memory for recalled and inhibited words in a recognition test. In perceptual identification by older adults, priming was equivalent for recalled and inhibited words, whereas in younger adults priming was higher for recalled than for inhibited words. In the explicit memory test, recognition scores were lower for inhibited words in both age groups. These results are consistent with the view of Hasher and Zacks (1988), who assume an age-related decline in the ability to suppress no-longer-relevant information     

Is the word length effect in STM entirely attributable to output delay? Evidence from serial recognition

Although it is generally accepted that the word length effect in short-term memory operates through output delay or interference, there is less agreement on whether it also influences performance through its impact on rehearsal. We investigated this issue by studying the effect of word length on recall and on a recognition task in which output delay was controlled. Word sequences were repeated exactly, or with one pair of words reversed. Two experiments using auditory presentation showed clear word length effects for both recall and serial recognition, although the magnitude of the effect tended to be less for recognition. A third experiment using visual presentation studied the effect of articulatory suppression during the recognition test; again we found a clear word length effect. It is concluded that the word length effect can influence retention through both rehearsal and output factors, as proposed by the phonological loop hypothesis.     

Encoding the world around us: Motor-related processing influences verbal memory

It is known that properties of words such as their imageability can influence our ability to remember those words. However, it is not known if other object-related properties can also influence our memory. In this study we asked whether a word representing a concrete object that can be functionally interacted with (i.e., high-manipulability word) would enhance the memory representations for that item compared to a word representing a less manipulable object (i.e., low-manipulability word). Here participants incidentally encoded high-manipulability (e.g., CAMERA) and low-manipulability words (e.g., TABLE) while making word judgments. Using a between-subjects design, we varied the depth-of-processing involved in the word judgment task: participants judged the words based on personal experience (deep/elaborative processing), word length (shallow), or functionality (intermediate). Participants were able to remember high-manipulability words better than low-manipulability words in both the personal experience and word length groups; thus presenting the first evidence that manipulability can influence memory. However, we observed better memory for low- than high-manipulability words in the functionality group. We explain this surprising interaction between manipulability and memory as being mediated by automatic vs. controlled motor-related cognition.     

A Dissociation Between Simple and Complex Span Impairment in Alcoholics

We investigated whether the surprisingly good memory performance of alcoholics may result from simple memory performance being spared while performance in complex memory tasks is impaired. Simple word span was contrasted with a complex word span task involving concurrent monitoring and re-organisation of items for recall. To control for disruption of rehearsal in the complex word span task, performance on two additional tasks with disrupted rehearsal but no additional processing components was studied. As hypothesised, the alcoholics showed a deficit in the complex but not the simple word span task. They were also impaired, compared to controls, on both tasks with disrupted rehearsal. The difference between groups remained in the complex span task when scores in simple span and either of the two other tasks were used as covariates. Thus, both executive processes necessary for coping with disrupted rehearsal and additional processes scheduling processing and storage in a complex task may play a role in accounting for working memory deficits found in alcoholics.     

Effects of lexical competition on immediate memory span for spoken words

Current theories and models of the structural organization of verbal short-term memory are primarily based on evidence obtained from manipulations of features inherent in the short-term traces of the presented stimuli, such as phonological similarity. In the present study, we investigated whether properties of the stimuli that are not inherent in the short-term traces of spoken words would affect performance in an immediate memory span task. We studied the lexical neighbourhood properties of the stimulus items, which are based on the structure and organization of words in the mental lexicon. The experiments manipulated lexical competition by varying the phonological neighbourhood structure (i.e., neighbourhood density and neighbourhood frequency) of the words on a test list while controlling for word frequency and intra-set phonological similarity (family size). Immediate memory span for spoken words was measured under repeated and nonrepeated sampling procedures. The results demonstrated that lexical competition only emerged when a nonrepeated sampling procedure was used and the participants had to access new words from their lexicons. These findings were not dependent on individual differences in short-term memory capacity. Additional results showed that the lexical competition effects did not interact with proactive interference. Analyses of error patterns indicated that item-type errors, but not positional errors, were influenced by the lexical attributes of the stimulus items. These results complement and extend previous findings that have argued for separate contributions of long-term knowledge and short-term memory rehearsal processes in immediate verbal serial recall tasks.     

Thinking of critical words during study is unnecessary for false memory in the Deese,Roediger, and McDermott procedure

Do participants in the Deese, Roediger, and McDermott (DRM) procedure demonstrate false memory because they think of nonpresented critical words during study and confuse them with words that were actually presented? In two experiments, 160 participants studied eight visually presented DRM lists at a rate of 2 s or 5 s per word. Half of the participants rehearsed silently: the other half rehearsed overtly. Following study, the participants' memory for the lists was tested by recall or recognition. Typical false memory results were obtained for both memory measures. More important, two new results were observed. First, a large majority of the overt-rehearsal participants spontaneously rehearsed approximately half of the critical words during study. Second, critical-word rehearsal at study enhanced subsequent false recall, but it had no effect on false recognition or remember judgments for falsely recognized critical words. Thinking of critical words during study was unnecessary for producing false memory.     

Strategy use in the reading span test: An analysis of eye movements and reported encoding strategies

Strategy use in the traditional reading span test was examined by recording participants’ eye movements during the task (Experiment 1) and by interviewing participants about their strategy use (Experiment 2). In Experiment 1, no differences between individuals with a low, medium, and high span were observed in how they distributed processing time between task elements. In all three groups, fixation times on words up to the to-be-remembered (TBR) word became shorter and the time spent on the TBR longer as memory load in the task increased. The results of Experiment 2, however, show that span groups differ in the use of memory encoding strategies: individuals with a low span use mainly rehearsal, whereas individuals with a high span use almost exclusively semantic elaboration. The results indicate that the use of elaborative strategies may enhance span performance but that not all individuals are necessarily able to use such strategies efficiently.     

Age related differences in metacognitive control: role of executive functioning

To examine whether aging affects metacognitive control, elderly and young adults carried out a readiness-recall task, in which subjects monitor their own learning procedure, allowing strategy manipulation (study time and rehearsal) to be measured. Age differences were observed in metamemory control performance. Younger adults were found to be better at adjusting study time and rehearsal to the task. Moreover, to determine whether age-related differences in strategy manipulation may mediate age-related differences in memory performance, performance on the readiness-recall task was compared to performance on an experimenter-paced task. Results indicated that younger adults recalled significantly more words in the readiness-recall task than in the experimenter test. This was not the case for older adults. Furthermore, a hierarchical regression analysis revealed that age-related differences in strategy manipulation mediate some age-related differences in memory performance. Our aim was also to determine whether metacognitive control is related to executive functions. Thus, all participants were administered standard neuropsychological tests used to assess executive functioning. Significant partial correlation appeared between metamemory control and executive functioning. Finally, a hierarchical regression analysis indicated that age-related decline in metamemory control may be largely the result of executive limitations associated with aging.     

Speech Intelligibility and Recall of Spoken Material Heard at Different Signal‐to‐noise Ratios and the Role Played by Working Memory Capacity

We studied speech intelligibility and memory performance for speech material heard under different signal‐to‐noise (S/N) ratios. Pre‐experimental measures of working memory capacity (WMC) were taken to explore individual susceptibility to the disruptive effects of noise. Thirty‐five participants first completed a WMC‐operation span task in quiet and later listened to spoken word lists containing 11 one‐syllable phonetically balanced words presented at four different S/N ratios (+12, +9, +6, and +3). Participants repeated each word aloud immediately after its presentation, to establish speech intelligibility and later on performed a free recall task for those words. The speech intelligibility function decreased linearly with increasing S/N levels for both the high‐WMC and low‐WMC groups. However, only the low‐WMC group had decreasing memory performance with increasing S/N levels. The memory of the high‐WMC individuals was not affected by increased S/N levels. Our results suggest that individual differences in WMC counteract some of the negative effects of speech noise. Copyright © 2012 John Wiley & Sons, Ltd.     

Visuospatial processing in memory for word location in writing

Two experiments examined how visuospatial processing engaged during text composition intervenes in memory for word location. Experiment 1 showed that in contrast to participants who performed a spatial task concurrently with composing a text, participants who performed a concurrent visual task recalled fewer word locations after the composition. Consequently, it is hypothesized that writers process the written text in order to visually represent its physical layout, and that this representation is then used when locating words. Experiment 2 tested this hypothesis by comparing a standard composition condition (with the written trace) with a condition in which the written trace was suppressed during composition, and with a condition without written trace and with added visual noise. Memory for word location only decreased with visual noise, indicating that construction of the visual representation of the text does not rely on the written trace but involves visual working memory.     

Evidence for spontaneous retrieval of suspended but not finished prospective memories

McDaniel and Einstein (2007) argued that prospective memories can be retrieved through spontaneous retrieval processes stimulated by the presence of a target cue. To test this claim, we investigated whether presenting a prospective memory cue during a task that did not require an intention to be performed spontaneously triggered remembering of that intention. In two experiments, participants performed an image-rating task in which a prospective memory task (to press the “Q” key when a target word appeared) was embedded. Then, participants were told that their intention was finished or suspended. Finally, participants performed a lexical decision task in which each target (and a matched control) word appeared. RTs were slower to target words than to control words when the intention was suspended but not when it was finished. These results suggest that target cues associated with suspended intentions can spontaneously trigger remembering but that finished intentions are quickly deactivated.     

Memory for affectively valenced and neutral stimuli in depression: Evidence from a novel matching task

Depressed persons have better memory for affectively negative than positive stimuli, a pattern generally not exhibited by non-depressed individuals. The mechanisms underlying this differential memory are not clear. In this study we examined memory for valenced and neutral stimuli in depressed and non-depressed individuals under conditions of relatively unconstrained encoding. We developed a novel task based on the game, Concentration, in which participants tried to match pairs of positive and negative words, and pairs of neutral words, hidden under squares in as few turns as possible. Whereas non-depressed participants selected and turned over positive squares more frequently than they did negative squares, depressed participants selected and turned over positive and negative squares equally often. Depressed participants also matched fewer positive word pairs within the first five minutes of the task than did non-depressed participants, and they exhibited poorer learning of positive words. Depressed and non-depressed participants did not differ in their matching of neutral words. These findings add to a growing literature indicating that depression is characterised by difficulties in the processing of positive stimuli.     

Rehearsal in immediate serial recall

We report for the first time overt rehearsal data in immediate serial recall (ISR) undertaken at three presentation rates (1, 2.5, and 5 sec/word). Two groups of participants saw lists of six words for ISR and were required either to engage in overt rehearsal or to remain silent after reading aloud the word list during its presentation. Typical ISR serial position effects were obtained for both groups, and recall increased with slower rates. When participants rehearsed, they tended to do so in a cumulative forward order up to Serial Position 4, after which the amount of rehearsal decreased substantially. There were similarities between rehearsal and recall data: Both broke down toward the end of longer sequences, and there were strong positive correlations between the maximum sequence of participants' rehearsals and their ISR performance. We interpret these data as suggesting that similar mechanisms underpin both rehearsal and recall in ISR.