A negative order-repetition priming effect: Inhibition of order in unattended auditory sequences?

A novel negative priming (NP) effect is reported in which serial recall for a sequence of visually presented digits was poorer if the same sequence was presented as an irrelevant auditory sequence on the previous trial (Experiments 1 and 2). The effect was enhanced when attention was divided between the to-be-repeated auditory sequence and the concurrent to-be-remembered (TBR) sequence (Experiment 3). When the TBR sequences were also presented auditorily, NP arose only when the repeated TBR sequence was in the same voice as the previous irrelevant sequence; a voice mismatch produced positive priming (Experiment 4). The results suggest that the order of auditory events is registered preattentively and that inhibition may be applied to the acoustic transitions between irrelevant events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Disruption of short-term memory by changing and deviant sounds: Support for a duplex-mechanism account of auditory distraction.

The disruption of short-term memory by to-be-ignored auditory sequences (the changing-state effect) has often been characterized as attentional capture by deviant events (deviation effect). However, the present study demonstrates that changing-state and deviation effects are functionally distinct forms of auditory distraction: The disruption of visual-verbal serial recall by changing-state speech was independent of the effect of a single deviant voice embedded within the speech (Experiment 1); a voice-deviation effect, but not a changing-state effect, was found on a missing-item task (Experiment 2); and a deviant voice repetition within the context of an alternating-voice irrelevant speech sequence disrupted serial recall (Experiment 3). The authors conclude that the changing-state effect is the result of a conflict between 2 seriation processes being applied concurrently to relevant and irrelevant material, whereas the deviation effect reflects a more general attention-capture process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequence learning and selection difficulty.

The authors studied the role of attention as a selection mechanism in implicit learning by examining the effect on primary sequence learning of performing a demanding target-selection task. Participants were trained on probabilistic sequences in a novel version of the serial reaction time (SRT) task, with dual- and triple-stimulus participants having to ignore irrelevant items in the SRT display. Despite large performance decrements under dual- and triple-stimulus configurations, testing under single-stimulus conditions revealed no impairment to sequence learning. These findings suggest that implicit sequence learning is resistant to disruption of the selection process. Results are discussed in terms of a componential model of attention and in relation to the implicit-explicit distinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Irrelevant Sound Phenomenon Revisited: What Role for Working Memory Capacity?

High-span individuals (as measured by the operation span [OSPAN] technique) are less likely than low-span individuals to notice their own names in an unattended auditory stream (A. R. A. Conway, N. Cowan, & M. F. Bunting, 2001). The possibility that OSPAN accounts for individual differences in auditory distraction on an immediate recall test was examined. There was no evidence that high-OSPAN participants were more resistant to the disruption caused by irrelevant speech in serial or in free recall. Low-OSPAN participants did, however, make more semantically related intrusion errors from the irrelevant sound stream in a free recall test (Experiment 4). Results suggest that OSPAN mediates semantic components of auditory distraction dissociable from other aspects of the irrelevant sound effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory Attentional Capture During Serial Recall: Violations at Encoding of an Algorithm-Based Neural Model?

A novel attentional capture effect is reported in which visual-verbal serial recall was disrupted if a single deviation in the interstimulus interval occurred within otherwise regularly presented task-irrelevant spoken items. The degree of disruption was the same whether the temporal deviant was embedded in a sequence made up of a repeating item or a sequence of changing items. Moreover, the effect was evident during the presentation of the to-be-remembered sequence but not during rehearsal just prior to recall, suggesting that the encoding of sequences is particularly susceptible. The results suggest that attentional capture is due to a violation of an algorithm rather than an aggregate-based neural model and further undermine an attentional capture-based account of the classical changing-state irrelevant sound effect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Organizational factors in selective attention: The interplay of acoustic distinctiveness and auditory streaming in the irrelevant sound effect.

A series of studies further explored the way in which irrelevant sound disrupts the serial recall of visually presented verbal sequences. The hypothesis that distinctiveness (stimulus mismatch) within auditory irrelevant sequences is a critical determinant of disruption of serial recall was tested. Experiment 1 showed that the degree of disruption was related to the degree of mismatch between successive stimuli. However, in Experiment 2, changes in 2 attributes of a stimulus produced less disruption than when only 1 was changed, suggesting mismatch alone was not the key factor. These results were reconciled with the changing-state hypothesis in Experiment 3 in which change and disruption were monotonically related up to the point at which mismatch created 2 streams. Object-based theories are able to explain this pattern of results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Irrelevant sound disrupts order information in free recall as in serial recall

The claim that the sensitivity of free recall to disruption by irrelevant sound is a function of the extent to which rote rehearsal is employed as a mnemonic strategy was investigated in two experiments. The degree of disruption by irrelevant sound in terms of both item and order information was contrasted under serial and free recall instructions. Irrelevant sound was found to disrupt order and item information equally in serial and free recall tasks (Experiment 1). Contrary to previous reports, an effect of irrelevant sound was also demonstrated on free recall of particularly long lists, and the interaction between list length and retention interval in the irrelevant sound effect was examined (Experiment 2). Generally, the results support the view that irrelevant sound disrupts the use of order cues.     

Learning of event sequences is based on response-effect learning: Further evidence from a serial reaction task.

Four experiments provide converging evidence that serial learning in a serial reaction task is based on response–effect learning, mediated by the learning of the relations between a response and the stimulus that follows it. In Experiment 1, the authors varied the stimulus sequence and the response–stimulus relations while holding the response sequence constant. Learning effects depended on the complexity of the response–stimulus relations but not on the stimulus–stimulus relations. In Experiment 2, transfer of serial learning from 1 stimulus sequence to another was only found when both sequences had identical response–stimulus relations. In Experiment 3, a variation of the stimulus sequence alone had no effect on serial learning, whereas in Experiment 4 learning effects increased when the response–stimulus relations but not the stimulus–stimulus relations were simplified. These findings suggest that serial learning is based on mechanisms of voluntary action control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When does between-sequence phonological similarity promote irrelevant sound disruption?

Typically, the phonological similarity between to-be-recalled items and TBI auditory stimuli has no impact if recall in serial order is required. However, in the present study, the authors have shown that the free recall, but not serial recall, of lists of phonologically related to-be-remembered items was disrupted by an irrelevant sound stream (end rhymes) sharing similar phonological content. These findings can be explained by the notion that between-sequence phonological similarity effects emerge when category-cueing processes become an important determinant for recall, such as when shared category information can be used as a retrieval aid to cue list items or plausible list candidates. In this case, the presence of categorically similar irrelevant items impairs the retrieval of list items and leads to intrusion error. Implications of these results for theories of auditory distraction are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of manipulation and irrelevant noise on working memory capacity of patients with Alzheimer's dementia.

The effect of manipulation and distracting noise on immediate serial recall was measured in patients with dementia of the Alzheimer type (DAT), neurologically healthy elderly individuals, and young adults. In Experiment 1, the authors compared serial word recall with word recall in alphabetical order. Alphabetical recall requires the active manipulation of the contents of working memory. Findings indicated that DAT patients were severely impaired in the alphabetical recall task, whereas the performance of neurologically healthy elderly participants was comparable with the performance of young adult participants. In Experiment 2, the authors investigated the effect of different irrelevant auditory backgrounds on immediate digit recall. In this task, both elderly participants and DAT patients performed similarly to the group of young adult participants, indicating comparable efficacy to resist auditory distraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonological similarity in the irrelevant speech effect: Within- or between-stream similarity?

Irrelevant background speech disrupts serial recall of visually presented lists of verbal material. In 4 experiments, the hypothesis that this disruption is due to the phonological similarity of the irrelevant sound and the list to be recalled was tested. In Experiment 1, item length was controlled and a large irrelevant speech effect was found, but the effect of phonological similarity was small and confined to recency. In Experiment 2, words in the irrelevant stream were used, and the experiment showed an irrelevant speech effect in which phonological similarity played a small part. Experiments 3 and 4 found that similarity (rhyming) within the irrelevant sound stream decreased the level of disruption, and the effect was more marked when the visually presented lists contained items that did not rhyme with one another. Rather than supporting a phonological similarity hypothesis, the results support a changing state hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional equivalence of verbal and spatial information in serial short-term memory.

Performance on a test of serial memory for the spatial position of a sequence of dots showed similarities to typical results from the serial recall of verbal material: a marked increase in error with increasing list length, a modest rise in error as retention interval increased, and bow-shaped serial position curves. This task was susceptible to interference from both a spatial task (rote tapping) and a verbal task (mouthed articulatory suppression) and also from the presence of irrelevant speech. Effects were comparable to those found with a serial verbal task that was generally similar in demand characteristics to the spatial task. As a generalization, disruption of the serial recall of visuospatial material was more marked if the interference conditions involved a changing sequence of actions or materials, but not if a single event (tap, mouthed utterance, or sound) was repeated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Capturing the suffix: Cognitive streaming in immediate serial recall.

Adding an irrelevant item to the end of an auditory to-be-remembered list increases error on the last list items appreciably, known as the suffix effect. The phenomenon of auditory capture (e.g., Bregman & Rudnicky, 1975), namely, the tendency for a sequence of similar items to form a stream that at the same time isolates perceptually dissimilar members of the sequence, is exploited to explore the suffix effect. Irrelevant items interleaved between to-be-remembered items are used to capture the suffix with the aim of reducing its impact. Four experiments illustrate how the properties of the irrelevant sequence promote capture. The results are problematic for models of the suffix that involve masking of the last list item; instead, models based on grouping are favored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explaining the irrelevant-sound effect: Temporal distinctiveness or changing state?

Task-irrelevant background sound disrupts serial recall. One account of this effect assumes that irrelevant events close to or during the presentation of a to-be-remembered list will interfere by disrupting temporal codes. A second account predicts that disruption will be greatest when the burden on rehearsal is high, as order cues in the auditory sequence interfere with those in the memory set. The authors tested these predictions by restricting the sound to different phases of the serial recall task. Sound presented just before the list and sound presented early in list presentation did not disrupt recall, but sound presented late in the list or after list presentation produced significant disruption. Sound presented after the list was more disruptive of recall for early list items than sound presented at the same time as those items. An account based on disruption of serial rehearsal, not the disruption of temporal codes, is supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of serial order in the irrelevant speech effect: Tests of the changing-state hypothesis.

The effects of irrelevant speech were examined on a range of memory tasks. A missing-item task, which relied on a nonserial strategy for recall, proved less sensitive to the effects of irrelevant speech than one calling on memory for serial order. The finding that the effect of irrelevant speech both on a recognition task and on a paired-associates task was modified significantly by articulatory suppression further suggested that memory for serial order is the dominant feature of these tasks and that it renders them vulnerable to disruption by irrelevant speech. Taken together, the results of the experimental series support the notion that tasks involving memory for serial order are particularly susceptible to disruption by irrelevant speech. These and other findings converge on the notion that interference with information processing by irrelevant sound is based on similarity of process rather than similarity of content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context-sensitive adjustments of cognitive control: Conflict-adaptation effects are modulated by processing demands of the ongoing task.

Dynamic adjustments of cognitive control in response to interference from irrelevant stimulus attributes have repeatedly been shown. The purpose of the current research was to investigate how these control adjustments are modulated by the processing demands of a primary task. To this end, the authors combined a primary task (a number comparison task: classifying digits as smaller or larger than 5) with a Simon task. Control adjustments were observed in the form of typical sequential modulations of the Simon effect. In addition, the authors found sequential modulations of the numerical distance effect and an interaction of both effects. Results suggest that not only response conflict due to interference from task-irrelevant features but also processing demands of task-relevant features determine the level of control adjustment in the subsequent trial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is level irrelevant in "irrelevant speech"? Effects of loudness, signal-to-noise ratio, and binaural unmasking

A series of experiments explored the role of level, signal-to-noise ratio, and the masking-level difference in the irrelevant speech effect (ISE). In Experiment 1 the detrimental effects of irrelevant sound on serial recall were found to be the same whether the material (speech or music) was presented at a high (75 dB[A]) or low (60 dB[A]) overall level. In Experiment 2, adding pink noise to the speech signal produced a linear improvement in performance with decreasing speech-to-noise ratios. In Experiment 3 the contribution of binaural unmasking to the ISE was found to be negligible. The results (a) confirm that the segmented, changing nature of the irrelevant sound is crucial in producing the ISE and (b) suggest that the adverse effects of disruptive auditory input may be alleviated by introducing additional uniform masking noise.     

The sandwich effect: The role of attentional factors in serial recall.

Five experiments tested the prediction, from a simple chaining model, that interleaving irrelevant material will substantially disrupt immediate serial recall. Exp 1 interpolated long or short words between items in an auditory digit span test. These 2 "sandwich" conditions disrupted recall to an equal but moderate extent. Exp 2 presented mixed lists of digits and words, cuing one or the other before or after presentation. Precuing led to substantially better recall. Exp 3 used articulatory suppression to rule out the hypothesis that recall was protected from the sandwich effect by subvocal rehearsal. Exp 4 combined the sandwich effect with a concurrent task, finding clear effects of both but no interaction. Exp 5 showed that the predictability of interpolated material did not influence recall. These results can be explained by adding an attentional preprocessor to standard chaining models. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The irrelevant sound effect: Does speech play a special role?

Memory for order is markedly impaired by the presence of irrelevant sound, even though participants are instructed to ignore the sound. Although a great deal of research has disclosed some features of the task and of the sound that augment or reduce the degree of interference, one important issue of the irrelevant sound effect not yet resolved is whether speech has a special status. This study revealed, within a design of adequate power, that the same physical stimulus (sine wave speech), whether perceived as speech or as nonspeech sound, produces similar degrees of disruption and is less disruptive of serial recall than natural speech. This outcome suggests that the acoustic constituents of sound rather than its source are most influential in determining the impact of irrelevant material. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial position effects in the identification of letters, digits, and symbols.

In 6 experiments, the authors investigated the form of serial position functions for identification of letters, digits, and symbols presented in strings. The results replicated findings obtained with the target search paradigm, showing an interaction between the effects of serial position and type of stimulus, with symbols generating a distinct serial position function compared with letters and digits. When the task was 2-alternative forced choice, this interaction was driven almost exclusively by performance at the first position in the string, with letters and digits showing much higher levels of accuracy than symbols at this position. A final-position advantage was reinstated in Experiment 6 by placing the two alternative responses below the target string. The end-position (first and last positions) advantage for letters and digits compared with symbol stimuli was further confirmed with the bar-probe technique (postcued partial report) in Experiments 5 and 6. Overall, the results further support the existence of a specialized mechanism designed to optimize processing of strings of letters and digits by modifying the size and shape of retinotopic character detectors' receptive fields. (PsycINFO Database Record (c) 2010 APA, all rights reserved)