Evolution on a volcanic conveyor belt: using phylogeographic reconstructions and K-Ar-based ages of the Hawaiian Islands to estimate molecular evolutionary rates

This article reports dissociations between verbal span and the recency portion of the serial position curve in immediate free recall, in 2 neuropsychological case studies and in 3 experiments with normal participants. Patient A. N. presented with an impaired serial verbal span while showing an intact recency effect. The opposite pattern was observed in patient G. C., who despite a poor recency showed normal span in verbal serial recall tasks. Experiments 1 and 2 showed a recency effect with visually and auditory presented lists and written recall was resistant to the effects of articulatory suppression and of irrelevant speech, but was disrupted by the suffix effect. Experiment 3 showed that in contrast with recency, memory span was affected by articulatory suppression and irrelevant speech during presentation but not by a suffix. These findings are not consistent with the idea that span and recency measure aspects of the same memory system. Moreover, in clinical practice, they should not be used as equivalent alternatives.     

Recency and suffix effects in serial recall of musical stimuli.

Previous research indicates that auditory presentation of verbal items leads to larger recency effects in recall than visual presentation. This enhanced recency can be eliminated if a stimulus suffix (an irrelevant sound) follows the last item. Four experiments, with 126 university students as Ss, tested the hypothesis that recency and suffix effects in serial recall result from a speech-specific process. It was demonstrated that serial recall of musical notes played on a piano exhibited substantial recency effects. These recency effects were reduced when the list items were followed by either a piano chord or the word start. However, a white-noise suffix had no effect on recency. It is concluded that this pattern of data is consistent with current work on auditory perception and places constraints on theories of recency and suffix effects. (55 ref) (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)     

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)     

Evaluating models of working memory through the effects of concurrent irrelevant information.

Working memory is believed to play a central role in almost all domains of higher cognition, yet the specific mechanisms involved in working memory are still fiercely debated. We describe a neuroimaging experiment with functional magnetic resonance imaging (fMRI) and a companion behavioral experiment, and in both we seek to adjudicate between alternative theoretical models of working memory on the basis of the effects of interference from articulatory suppression, irrelevant speech, and irrelevant nonspeech. In Experiment 1 we examined fMRI signal changes induced by each type of irrelevant information while subjects performed a probed recall task. Within a principally frontal and left-lateralized network of brain regions, articulatory suppression caused an increase in activity during item presentation, whereas both irrelevant speech and nonspeech caused relative activity reductions during the subsequent delay interval. In Experiment 2, the specific timing of interference was manipulated in a delayed serial recall task. Articulatory suppression was found to be most consequential when it coincided with item presentation, whereas both irrelevant speech and irrelevant nonspeech effects were strongest when limited to the subsequent delay period. Taken together, these experiments provide convergent evidence for a dissociation of articulatory suppression from the 2 irrelevant sound conditions. Implications of these findings are considered for 4 prominent theories of working memory. (PsycINFO Database Record (c) 2011 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 Phonological Store of Working Memory: Is It Phonological and Is It a Store?

The phonological store construct of the working memory model is critically evaluated. Three experiments test the prediction that the effect of irrelevant sound and the effect of phonological similarity each survive the action of articulatory suppression but only when presentation of to-be-remembered lists is auditory, not visual. No evidence was found to support the interaction predicted among irrelevant speech, modality, and articulatory suppression. Although evidence for an interaction among modality, phonological similarity, and articulatory suppression was found, its presence could be diminished by a suffix, which is an acoustic, not a phonological factor. Coupled with other evidence-from the irrelevant sound effect and errors in natural speech-the action attributed to the phonological store seems better described in terms of a combination of auditory-perceptual and output planning mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional characteristics of the inner voice and the inner ear: Single or double agency?

Double agency theories of short-term memory posit the functional independence of a phonological store (inner ear) and articulatory process (inner voice). A series of 5 experiments challenges this view. Articulatory suppression during retention of 9-item lists gives rise to a changing-state effect similar to that shown for irrelevant speech. Also, vocalized suppression is more disruptive than silently mouthed suppression, but this difference arises from vocalization itself rather than from any auditory feedback to which it gives rise. Class similarity between the to-be-remembered items and the articulatory material is not a critical determinant, but the effect occurs only with tests of serial order. For mouthed suppression, the irrelevant speech effect is only attenuated with changing-state suppression. Also, the presence of changing-state irrelevant speech abolishes the changing-state effect of articulatory suppression. Functional equivalence of codes from auditory, visual, and articulatory sources is claimed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonological loop and intermittent activity: A whistle task as articulatory suppression.

Examined whether the effect of articulatory suppression is due to the activation of an irrelevant phonology or to intermittent articulatory movements. In Exp 1, 24 undergraduates were tested for serial recall of visually presented letter sequences that were either phonologically similar or dissimilar, and had to remember each of the letter sequences under a no-suppression control or a suppression condition. In the suppression condition, half of the Ss were engaged in an intermittent speech suppression and the other half were in an intermittent whistle suppression task. The phonological similarity effects appeared in the control condition, but not in the suppression condition, irrespective of the type of suppression. In Exp 2, the phonological similarity effect again disappeared in the intermittent whistling condition, but not in the condition in which the 15 undergraduates required to engage a continuous whistling task. The results suggest that the effect of articulatory suppression was due to intermittent articulatory activity rather than the activation of an irrelevant phonology. (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)     

Revisiting evidence for modularity and functional equivalence across verbal and spatial domains in memory.

The authors revisited evidence in favor of modularity and of functional equivalence between the processing of verbal and spatial information in short-term memory. This was done by investigating the patterns of intrusions, omissions, transpositions, and fill-ins in verbal and spatial serial recall and order reconstruction tasks under control, articulatory suppression, and spatial tapping conditions. The authors observed that when tasks were fully equated, all patterns of errors were equivalent between the verbal and spatial domains. Moreover, articulatory suppression interfered more with the verbal memory tasks than with the spatial memory tasks. This interference was mostly due to an increase of omissions and transpositions. Similarly, tapping was more disruptive of spatial memory than of verbal memory tasks and affected primarily the number of omissions and transpositions. The patterns of errors and their interaction with interference are discussed in light of the predominant approaches to modeling memory and provide a rich set of data for modeling efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional characteristics of auditory temporal—spatial short-term memory: Evidence from serial order errors.

The functional characteristics of auditory temporal-spatial short-term memory were explored in 8 experiments in which the to-be-remembered stimuli were sequences of bursts of white noise presented in spatial locations separated in azimuth. Primacy and recency effects were observed in all experiments. A 10-s delay impaired recall for primacy and middle list items but not recency. This effect was shown not to depend on the response modality or on the incidence of omissions or repetitions. Verbal and nonverbal secondary tasks did not affect memory for auditory spatial sounds. Temporal errors rather than spatial errors predominated, suggesting that participants were engaged in a process of maintaining order. This pattern of results may reflect characteristics that serial recall has in common with verbal and spatial recall, but some are unique to the representation of memory for temporal-spatial auditory events. (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)     

Extending the irrelevant speech effect beyond serial recall.

The irrelevant speech effect is the impairment of immediate memory by the presentation of to-be-ignored speech stimuli. The irrelevant speech effect has been limited to serial recall, but this series of 8 experiments demonstrates that it is considerably more general. Exps 1–3 show that (1) irrelevant speech inhibits free recall more than does white noise, (2) irrelevant speech impairs free recall even when the speech occurs after the to-be-recalled items, and (3) free recall is inhibited even when the speech is meaningless. Exp 4 failed to find an effect in free recall with 16-item lists. Exps 5A–5C extend the effect to recognition of 8-, 12-, and 16-item lists, with both phonologically related and phonologically unrelated lure items. Exp 6 extends the effect to a cued recall task that discourages the use of serial rehearsal of the to-be-remembered items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memorial and strategic determinants of tactile recency.

Across 4 experiments, recency arising from the presentation of 5-item tactile lists was assessed with immediate and delayed recall with or without a same-modality suffix. The lists were presented with or without concurrent verbalization and at rates varying from 0.5 s to 2 s per item. Delaying recall or the addition of a suffix impaired recency both in the absence of concurrent verbalization during list presentation and at the 1-s presentation rate. In contrast, both concurrent verbalization during list presentation and a 0.5-s presentation rate restored recency for both the delayed recall and suffix conditions. This pattern of data is problematic for sensory memory and for trace discriminability accounts of modality and suffix effects. It is suggested that a sensory memory account together with an attention-biasing strategy by which limited encoding resources are diverted toward the terminal list item can better accommodate the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immediate and delayed recall of words and pictures.

Examined free and serial recall of words and pictures associates in 3 experiments with 156 Ss. In immediate free recall, presentation of pictorial material increased only the secondary memory component of recall, relative to conditions involving presentation of verbal materials. No such facilitation occurred in immediate serial recall. In delayed recall tests, negative recency effects were obtained only for verbal materials, in both free and serial recall. Recency effects were either nonnegative or positive with pictures as to-be-remembered material. Results are discussed in terms of the locus of word-picture differences and the adequacy of verbal memory model explanations for them. (French summary) (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)     

Concrete words are easier to recall than abstract words: Evidence for a semantic contribution to short-term serial recall.

Immediate serial recall and maximal speech rate were assessed for concrete and abstract words differing in length. Experiment 1 showed large advantages for spoken recall of concrete words that were independent of speech rate. Experiment 2 showed an equivalent effect with written, rather than spoken, recall. Experiment 3 showed that the concreteness effect was still present when recall was backward rather than forward. In all 3 experiments, concrete words enjoyed an advantage that was roughly constant across all serial positions (with the possible exception of the 1st and last items). Experiment 4 used a matching-span procedure and showed that when there was no requirement for linguistic output, the effect of concreteness (but not the effect of word length) was eliminated. It is argued that semantic coding exerts powerful effects in verbal short-term memory tasks that have generally been underestimated. (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)     

The role of item-specific information for the serial position curve in free recall.

The serial position curve in free recall of a list of action phrases differs depending on whether the phrases were memorized by listening/reading (verbal task; VT) or by additionally enacting the denoted actions (subject-performed task; SPT). In VTs there is a clear primacy effect and a short recency effect. In SPTs there is no primacy effect but an extended recency effect. H. D. Zimmer, T. Helstrup, and J. Engelkamp (2000) assumed that SPTs provide excellent item-specific information, which leads to an automatic pop-out of the items presented last. In the present study, the authors assumed that good item-specific encoding generally enhances the recency effect and that it hinders rehearsal processes and thereby reduces the primacy effect. This assumption was confirmed. An item-specific orienting task leads to parallel serial position curves in VTs and SPTs with no primacy effect but a clear recency effect. Moreover, the same serial position effects were shown with nouns as learning material. An item-specific orienting task changes the classical U-shaped serial position curve with verbal material and leads to the disappearance of the primacy and the enhancement of the recency effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)