PubMed Health⌕ Search

Biomedical subjects

Alan Baddeley

Publications and source records attributed to Alan Baddeley.

8 recordsLinked to original sources
PubMed2004

Irrelevant sound disrupts speech production: exploring the relationship between short-term memory and experimentally induced slips of the tongue.

To explore the relationship between short-term memory and speech production, we developed a speech error induction technique. The technique, which was adapted from a Japanese word game, exposed participants to an auditory distractor word immediately before the utterance of a target word. In Experiment 1, the distractor words that were phonologically similar to the target word led to a greater number of errors in speaking the target than did the dissimilar distractor words. Furthermore, the speech error scores were significantly correlated with memory span scores. In Experiment 2, memory span scores were again correlated with the rate of the speech errors that were induced from the task-irrelevant speech sounds. Experiment 3 showed a strong irrelevant-sound effect in the serial recall of nonwords. The magnitude of the irrelevant-sound effects was not affected by phonological similarity between the to-be-remembered nonwords and the irrelevant-sound materials. Analysis of recall errors in Experiment 3 also suggested that there were no essential differences in recall error patterns between the dissimilar and similar irrelevant-sound conditions. We proposed two different underlying mechanisms in immediate memory, one operating via the phonological short-term memory store and the other via the processes underpinning speech production.

Acoustic Stimulation↗
PubMed2003

The irrelevant speech effect: a PET study.

Positron emission tomography (PET) was performed in normal volunteers during a serial recall task under the influence of irrelevant speech comprising both single item repetition and multi-item sequences. An interaction approach was used to identify brain areas specifically related to the irrelevant speech effect. We interpreted activations as compensatory recruitment of complementary working memory processing, and decreased activity in terms of suppression of task relevant areas invoked by the irrelevant speech. The interaction between the distractors and working memory revealed a significant effect in the left, and to a lesser extent in the right, superior temporal region, indicating that initial phonological processing was relatively suppressed. Additional areas of decreased activity were observed in an a priori defined cortical network related to verbal working memory, incorporating the bilateral superior temporal and inferior/middle frontal cortices extending into Broca's area on the left. We also observed a weak activation in the left inferior parietal cortex, a region suggested to reflect the phonological store, the subcomponent where the interference is assumed to take place. The results suggest that the irrelevant speech effect is correlated with and thus tentatively may be explained in terms of a suppression of components of the verbal working memory network as outlined. The results can be interpreted in terms of inhibitory top-down attentional mechanisms attenuating the influence of the irrelevant speech, although additional studies are clearly necessary to more fully characterize the nature of this phenomenon and its theoretical implications for existing short-term memory models.

Acoustic Stimulation↗
PubMed2003

Disruption of verbal STM by irrelevant speech, articulatory suppression, and manual tapping: do they have a common source?

Under appropriate conditions, immediate serial verbal recall is impaired by irrelevant speech, articulatory suppression, and syncopated tapping. Interpretation of these variables in terms of the phonological loop component of working memory assumes separate phonological storage and articulatory rehearsal processes. In contrast, the Object-Oriented Episodic Record (O-OER) of Jones and the feature theory of Neath interpret these and other phenomena in terms of a unitary multimodal system. Three experiments investigate these disrupting tasks, with each experiment emphasizing one parameter. In each case, recall of phonologically similar and dissimilar letter sequences is compared as a marker of the presence or absence of phonological coding. In Experiment 1, subjects heard or articulated a single item, or tapped a single key at equal intervals. Only articulatory suppression impaired performance; it also abolished the effects of phonological similarity. Experiment 2 was identical, except that items were heard, or generated in a syncopated rhythm. Both suppression and tapping impaired performance to an equivalent extent and obliterated the effect of phonological similarity. Syncopated irrelevant speech caused a modest but significant impairment in performance. Experiment 3 was identical to Experiment 1, except that six tokens were used. Irrelevant speech and tapping had a clear impact on recall, but neither removed the phonological similarity effect. Again articulatory suppression had a major impact on performance and removed the effect of phonological similarity. We conclude that the pattern of results readily fits the phonological loop hypothesis, provided one accepts Saitos proposal that generating syncopated sequences uses common processes with speech production. It is not clear how the results can be explained by either the O-OER or the feature hypothesis.

Acoustic Stimulation↗
PubMed2002

Prose recall and amnesia: implications for the structure of working memory.

Two densely amnesic patients are shown to have good immediate but poor delayed prose recall, a result that presents problems for the current multi-component model of working memory. Examination of a wide sample of memory impaired patients suggests that this pattern occurs in densely amnesic patients who have well-preserved intelligence and good executive capacities. Patients suffering from Alzheimer's disease typically show poor immediate and delayed prose recall, reflecting their combined intellectual and memory deficits. The results are interpreted in terms of a proposed new component of working memory, the episodic buffer.

Adolescent↗
PubMed2002

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.

Adult↗
PubMedDate not supplied

Working memory and language: an overview.

Working memory involves the temporary storage and manipulation of information that is assumed to be necessary for a wide range of complex cognitive activities. In 1974, Baddeley and Hitch proposed that it could be divided into three subsystems, one concerned with verbal and acoustic information, the phonological loop, a second, the visuospatial sketchpad providing its visual equivalent, while both are dependent upon a third attentionally-limited control system, the central executive. A fourth subsystem, the episodic buffer, has recently been proposed. These are described in turn, with particular reference to implications for both the normal processing of language, and its potential disorders. The reader will be introduced to the concept of a multi-component working memory. Particular emphasis will be placed on the phonological loop component, and (a) its fractionation into a storage and processing component, (b) the neuropsychological evidence for this distinction, and (c) its implication for both native and second language learning. This will be followed by (d) a brief overview of the visuospatial sketchpad and its possible role in language, culminating in (e) discussion of the higher-level control functions of working memory which include (f) the central executive and its multi-dimensional storage system, the episodic buffer. An attempt throughout is made to link the model to its role in both normal and disordered language functions.

Acoustics↗