Irrelevant speech and irrelevant tones: The relative importance of speech to the irrelevant speech effect.

Irrelevant auditory stimuli disrupt immediate serial recall. In the equipotentiality hypothesis, D. M. Jones and W. J. Macken (see record 1993-20312-001) made the controversial prediction that speech and tones have an equivalent disruptive effect. In the present study, 5 experiments tested their hypothesis. Experiments 1–4 showed that meaningful speech disrupts recall more than do tones. Experiments 3 and 4 provided some evidence that meaningful speech disrupts recall more than does meaningless speech, and Experiment 4 showed that even meaningless speech disrupts recall more than do tones. Using slightly different experimental procedures, Experiment 5 showed that letters disrupt recall more than do tones. Implications of these results for a number of theories of primary memory and the irrelevant speech effect are discussed. (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)     

Irrelevant speech, serial rehearsal, and temporal distinctiveness: A new approach to the irrelevant speech effect.

D. C. LeCompte (see record 1995-04375-001) showed that the irrelevant speech effect—that is, the impairment of performance by the presentation of irrelevant background speech—extends to free recall, recognition, and cued recall. The present experiments extended the irrelevant speech effect to the missing-item task (Experiments 1 and 2), thereby contradicting a key prediction of the changing state hypothesis, which states that tasks that do not involve serial rehearsal should not be affected by the presence of irrelevant speech. Temporal distinctiveness theory provides an alternative explanation of the irrelevant speech effect. Experiment 3 tested and confirmed a unique prediction of this theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Directly assessing the relationship between irrelevant speech and irrelevant tapping.

The acoustic confusion effect is the finding that lists of to-be-remembered items that sound similar to one another are recalled worse than otherwise comparable lists of items that sound different. Previous work has shown that concurrent irrelevant speech and concurrent irrelevant tapping both reduce the size of this effect, suggesting similarities between the two manipulations. The authors assessed the relation between irrelevant speech and irrelevant tapping by correlating the disruption each causes to recall of similar- and dissimilar-sounding items. A significant correlation was obtained, indicating a relation between the two. The results indicate that researchers should be sensitive to changes in the magnitude of the effects rather than focusing exclusively on the presence or absence of particular effects. Implications for the 3 major explanations of the irrelevant speech effect are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of concurrent semantic categorization on delayed serial recall.

The influence of semantic processing on the serial ordering of items in short-term memory was explored using a novel dual-task paradigm. Participants engaged in 2 picture-judgment tasks while simultaneously performing delayed serial recall. List material varied in the presence of phonological overlap (Experiments 1 and 2) and in semantic content (concrete words in Experiment 1 and 3; nonwords in Experiments 2 and 3). Picture judgments varied in the extent to which they required accessing visual semantic information (i.e., semantic categorization and line orientation judgments). Results showed that, relative to line-orientation judgments, engaging in semantic categorization judgments increased the proportion of item-ordering errors for concrete lists but did not affect error proportions for nonword lists. Furthermore, although more ordering errors were observed for phonologically similar relative to dissimilar lists, no interactions were observed between the phonological overlap and picture-judgment task manipulations. These results demonstrate that lexical-semantic representations can affect the serial ordering of items in short-term memory. Furthermore, the dual-task paradigm provides a new method for examining when and how semantic representations affect memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in susceptibility to the "irrelevant speech effect"

Individual differences in objective effects of noise on performance were analyzed with respect to their distribution, temporal stability, and the precision of measurement to be attained. Seventy-two subjects had to memorize sequences of visually presented digits while being exposed to one of three auditory background conditions which were randomly mixed on a trial-by-trial basis: (1) foreign speech; (2) pink noise; and (3) silence. Individual "irrelevant speech effects," operationalized by the difference in recall errors under speech and in silence, were normally distributed over a wide range extending from slight facilitation to severe disruption. When 25 subjects repeated the experiment after four weeks, the individual differences were replicated with a reliability of rtt = 0.45. Internal consistency, a measure of the precision with which individual effects can be measured in a single session, was moderate (alpha = 0.55). However, both retest, and consistency coefficients are severely attenuated by the use of (sound-minus-silence) difference scores, the reliability of which is bound to be considerably lower than that of the original error scores whenever these are correlated. Given that the original error rates in a specific auditory condition can be determined with reliabilities approaching 0.85, it may be concluded that individual performance decrements due to noise can be reliably measured in the "irrelevant speech" paradigm. Self-report measures of noise susceptibility collected to explore potential sources of the large inter-individual variation exhibited only weak relationships with the objectively measured noise effects: Subjects were quite inaccurate in assessing their individual impairment in the three auditory conditions, and a questionnaire-based measure of general noise sensitivity only accounted for a small portion of the variance in objectively measured performance decrements, although in both cases the predictive relationship was much stronger in female than in male subjects.     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immediate serial recall of mixed-modality lists.

Seven experiments are reported in which subjects were tested for immediate serial recall of mixed-modality lists. On mixed auditory-visual lists, there was an advantage for auditory items at all serial positions. This was due to both a facilitation of auditory items and an inhibition of visual items on mixed lists, as compared with single-modality lists. When presented on a list containing items read silently, recall of items that were silently mouthed by the subject demonstrated patterns similar to those found with auditory items. When presented on a list containing items read aloud, recall of mouthed items showed patterns similar to those found with silently read items. The auditory advantage on mixed lists was found even when the list items were acoustically similar or identical and was not reduced by midlist auditory suffixes. The results suggest that modality differences in recall of mixed-modality lists are based on information different from that responsible for modality differences in recall of single-modality lists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

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)     

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)     

Factors in the serial recall of names of acquaintances.

2 experiments in recall were conducted to determine the effects of pleasure, frequency, recency, acquaintance, and construction variables, and to compare the effect of the pleasure variable with that of height in order to rule out extraneous ranking habits. In the first experiment 137 Ss were given a first name and asked to recall 8 living acquaintances who had this name. Then they were asked to rank the recalled names as to: (1) how well they liked each person; (2) how frequently they have had contact; (3) how recently; and (4) how well they know him. They were also asked to put the names into 3 groups so that each group was alike and at the same time different from the other groups. Rankings in the first 4 tasks were highly correlated with the order in which the names were recalled. On the grouping task, order of recall fell short of a significant relationship with the construct groupings. 24 Ss were used in the second experiment. The pleasure-order of recall correlation was significantly greater than 0, but the height-order of recall was not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Irrelevant tones produce an irrelevant speech effect: Implications for phonological coding in working memory.

Addresses the possibility that tones disrupt serial recall of visually presented material in the same way as speech. A stream of changing tones is as disruptive of visual serial recall as 4 syllables (Exps 1 and 2). Similar effects were also shown with a repeated syllable that changed only in pitch (Exp 3). Just as for speech, the effect of tones is not at encoding but during storage of the serial lists (Exp 4 and 5). The results suggest that speech and tones are equipotent in their capacity to disrupt short-term memory. A "blackboard" model of working memory to account for the effects is outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative relatedness enhances recall and produces false memories in immediate serial recall.

The influence of permanent lexical network in immediate serial recall is well established. The corresponding influence of permanent semantic networks is less clear, although such networks are known to both facilitate memory in long-term memory tasks and to produce false memories in those same tasks. The current experiment involves the study of Deese-Roediger-McDermott (DRM) lists for immediate serial recall. The trials in the experiment involved presenting the six strongest items from the DRM lists either in intact associatively related lists or where those items had been randomly mixed to produce unrelated lists. The results of the experiment indicated that the associatively related lists were better recalled in order than unrelated lists and the nonpresented critical lure was falsely recalled relatively frequently. The results of the experiment confirm the importance of associative semantic networks in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Suffix interference in the recall of linguistically coherent speech.

In Exp 1, definitions of low-frequency words were presented for on-line written recall. Each definition was followed by a nonword speech suffix presented in the same voice as the definition, the same nonword presented in a different voice, or a tone. There was a significant reduction in the recall of the terminal words of the definitions in the speech suffix conditions compared with the tone control. This pattern was replicated in Exp 2, in which Ss did not begin their recall until the suffix item or tone was presented, although the magnitude of the suffix effect was reduced in this experiment. In Exp 3, the suffix effect was considerably reduced compared with the suffix effect found with the definitions presented in Exps 1 and 2. This pattern was replicated in Exp 4, in which Ss did not begin their recall of the story sentences until the speech suffix or tone was presented. Results suggest that auditory memory interference can take place for linguistically coherent speech, although the magnitude of the interference decreases as one increases the level of linguistic structure in the to-be-recalled materials. (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)     

Contextual variability and serial position effects in free recall.

In immediate free recall, words recalled successively tend to come from nearby serial positions. M. J. Kahana (see record 1996-93836-009) documented this effect and showed that this tendency, which the authors refer to as the lag recency effect, is well described by a variant of the search of associative memory (SAM) model (J. G. W. Raaijmakers & R. M. Shiffrin, 1980, 1981). In 2 experiments, participants performed immediate, delayed, and continuous distractor free recall under conditions designed to minimize rehearsal. The lag recency effect, previously observed in immediate free recall, was also observed in delayed and continuous distractor free recall. Although two-store memory models, such as SAM, readily account for the end-of-list recency effect in immediate free recall, and its attenuation in delayed free recall, these models fail to account for the long-term recency effect. By means of analytic simulations, the authors show that both the end of list recency effect and the lag recency effect, across all distractor conditions, can be explained by a single-store model in which context, retrieved with each recalled item, serves as a cue for subsequent recalls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissimilar items benefit from phonological similarity in serial recall.

In short-term serial recall, similar sounding items are remembered less well than items that do not sound alike. This phonological similarity effect has been observed with lists composed only of similar items, and also with lists that mix together similar and dissimilar items. An additional consistent finding has been what the authors call dissimilar immunity, the finding that ordered recall of dissimilar items is the same whether these items occur in pure dissimilar or mixed lists. The authors present 3 experiments that disconfirm these previous findings by showing that dissimilar items on mixed lists are recalled better than their counterparts on pure lists if order errors are considered separately from intrusion errors (Experiment 1), or if intrusion errors are experimentally controlled (Experiments 2 and 3). The memory benefit for dissimilar items on mixed lists poses a challenge for current models of short-term serial recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regaining lost time: Adult aging and the effect of time restoration on recall of time-compressed speech.

Two experiments in which time was restored to artificially accelerated (time-compressed) speech are reported. Experiment I showed that although both young and older adults' recall of the speech benefited from the restoration of time, time restoration failed to boost the older adults to their baseline levels for unaltered speech. In Experiment 2, either 100% or 125% of lost time was restored by inserting pauses, either at linguistic boundaries or at random points within the passages. Experiment 2 showed that the beneficial effects of time restoration depended on where processing time was inserted, as well as how much time was restored. Results are interpreted in terms of age-related slowing in speech processing moderated by preserved linguistic knowledge and short-term conceptual memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)