Elsevier

Cortex

Volume 112, March 2019, Pages 107-121
Cortex

Special issue: Review
Impairments of auditory-verbal short-term memory: Do selective deficits of the input phonological buffer exist?

https://doi.org/10.1016/j.cortex.2018.10.004Get rights and content

Abstract

The existence of the functional syndrome of auditory-verbal short-term storage impairment was used as strong supporting evidence for the presence of a phonological buffer in the first version of the Baddeley–Hitch working memory model. In later versions the syndrome corresponded to the selective impairment of the phonological input buffer. The present paper considers whether the correspondence between the functional syndrome, represented by 20 published cases, and a Baddeley–Hitch model component is still of value to memory theory. The following potential problems for the theoretical utility of the correspondence are considered:

1. The apparent rarity of examples of the syndrome: are they outliers?

2. Is short-term memory not merely the activation of long-term memory traces?

3. Could the syndrome be due to failed interaction between perceptual and motor speech processing?

4. Do some aspects of the syndrome not fit the Baddeley–Hitch model predictions?

5. Has the Baddeley–Hitch model not been replaced by more powerful connectionist models?

6. Could the syndrome arise from weakened speech perception processes?

It is argued that there are difficulties for each of these possibilities. It is held that the correspondence retains its value.

Introduction

For a variety of reasons it has long been popular in cognitive science to assume that the storage of information over the short-term involves different systems or processes from those involved in the storage of information over the longer term. However, the position was really dominant in the 1960s and 1970s when a variety of models were produced which involved a short-term memory (STM) concept in different ways. Most saw STM and long-term memory (LTM) as being in series – the so-called ‘modal model’ (e.g., Atkinson and Shiffrin, 1968, Murdock, 1974, Waugh and Norman, 1965).

From a somewhat different perspective, Baddeley and Hitch (1974) put forward what became much the most popular framework. For them, short-term recall is primarily carried out by storage in modality specific short-term stores (STSs) or buffers, such as a phonological buffer and the visuo-spatial sketchpad (or at times scratchpad). Later they were refined: thus the phonological buffer became a phonological input buffer (Baddeley, 1986), while the visuo-spatial sketchpad was divided into a visual cache (for information about form and colour) and an inner scribe (for spatial and movement information) (Logie (1995). Their primary functions are to facilitate cognitive operations and not to act as holding systems for laying down traces in long-term systems such as episodic and semantic memory. They are also components of larger cognitive networks: so the phonological input buffer together with articulatory rehearsal form the phonological loop. The inner scribe performs an analogous rehearsal role for the contents of the visual cache.

Baddeley has used different terms such as ‘STSs’ and ‘buffers’ (e.g., Baddeley and Hitch, 1974, Baddeley et al., 1975) to label systems involved specifically in short-term retention of information. We will use the term ‘buffer’, because it makes the computational functions of such systems clearer. A buffer in computer science is an area of memory where data can be stored so that it can be accessed more rapidly if a processing unit needs it. For cognitive science purposes (see Shallice & Cooper, 2011), we ascribe to the concept buffer four properties: (i) the existence of a mechanism for short-term retention of a set of item-traces, (ii) that the information so retained is of a specific type (e.g., graphemic, visuo-spatial), (iii) that the information so stored is accessible by some mechanism for rapid reactivation of the individual traces, and (iv) that the stored representation contains information on some dimension distinct from the content of the individual item-traces, such as temporal or spatial position. The third property derives from the need for rapid writing from the buffer; this seems to entail the fourth property too. We do not ascribe to our use of the term any more specific buffer-like property such as its containing a fixed number of ‘slots’ (Neisser, 1967). However, for the phonological input buffer, we have the additional property, that being an integral part of the language system, its contents can be accessed at a variety of points from semantic and/or syntactic retrieval cues (see Butterworth et al., 1990, Saffran, 1990).

The idea that STM and LTM primarily utilise different systems or processes did not go uncontested even during its most fashionable period (e.g., Melton, 1963). Later, the rival notion was suggested that STM is merely the product of activation of LTM traces (e.g., Cowan, 1995, Oberauer, 2002). With the advent of functional magnetic resonance imaging (fMRI) this position became increasingly popular (e.g., D'Esposito & Postle, 2015; Jonides et al., 2008, Postle, 2006, Ranganath and Blumenfeld, 2005).

Early on, a variety of types of behavioural evidence were put forward for the separation of STM and LTM systems or processes. For instance, free recall of word lists is well known to give rise to a curve which reflects the serial position in which the word was originally presented. It has three components – a declining primacy effect, a flattish middle section, and a rising recency effect. That different manipulations, such as varying the rate of presentation or adding a filled delay before retrieval, affect the pre-recency (i.e., primacy and middle sections) and recency parts of the serial position curve in contrasting fashions was shown by Glanzer and Cunitz (1966) and these components were held to relate to LTM-related and STM-related processes respectively. However, alternative interpretations of the free recall recency effect became fashionable in the 1970s (Greene, 1986).

Secondly, Conrad (1964) and Baddeley, 1966a, Baddeley, 1996b showed that phonological similarity but not semantic similarity had a very detrimental effect on short-term retention, but it was semantic similarity not phonological similarity that affected long-term retention if short-term retention was controlled. Here too, though, effects of phonological similarity were later found in some paradigms using long-term retention (e.g., free recall (Bruce & Crowley, 1970)). The behavioural evidence was not entirely clear cut.

Critically, though, the two types of behavioural evidence in favour of separation of STM and LTM processes are mutually reinforcing. In the free recall task errors made in the recency part of the serial position curve are primarily phonological and those in the pre-recency part of the curve are primarily semantic (Craik, 1968, Shallice, 1975). We will see that this type of mutual support can be extended to neuropsychological evidence too.

Baddeley and Hitch (1974) in their classic initial paper had also put a lot of weight on the neuropsychological evidence, and in particular, on what we call, the ‘auditory-verbal short-term memory (A-V STM) syndrome’ and its contrast with classical amnesia. These types of disorder were seen as arising from damage to the two types of system – STM, and in particular a phonological buffer, and LTM – respectively.

In sum, there is critical evidence supporting a distinction between two types of system, STM and LTM.

Section snippets

The putative functional syndrome

Patients with a selective impairment of A-V STM then retain their potential theoretical importance. Such a disorder was first described by Warrington and Shallice (1969) in a single patient, KF as a selective deficit in span tasks. Luria, Sokolov & Klimskowski (1967) had reported two patients, B and K, with quite similar characteristics, but had conceived of them in terms of more traditional memory theory, such as an increased build-up of inhibition. A number of further single cases who are

The theoretical relevance of the putative functional syndrome

It was argued by Shallice and Warrington (1970) that the locus of KF's impairment lay in a STS at the level of the phonological analysis of the input. This corresponds to a deficit to the phonological input buffer on the later versions of the Baddeley–Hitch working memory model. This, then, becomes a plausible basis of the putative functional syndrome.

A host of alternative possibilities have, however, been put forward. They will be discussed later. First, though, it is appropriate to consider

Alternative perspectives on the behaviour of the A-V STM patients

The support that the A-V STM patients provide for the Baddeley–Hitch working memory model, as showing that the phonological input buffer can be selectively impaired in a group of patients, is discounted by number of more recent theorists for a variety of reasons. The first three positions reject the utility of the A-V STM syndrome concept or that of buffers or both. The fourth, by contrast, accepts the syndrome concept but argues that it does not fit the properties to be expected given the

Discussion

The set of models of working memory initiated by Baddeley and Hitch in 1974 have many properties. All, however, have included a store holding phonologically specified contents over short intervals of time. Later versions (e.g., Baddeley, 1986, Baddeley, 2000) characterise it as a phonological input buffer. Our paper is concerned solely with this component of their models. We have argued that while other storage systems such as semantic ones, a visuo-spatial sketchpad and a phonological output

Declaration of interest

None.

References (130)

  • D. Bruce et al.

    Acoustic similarity effects on retrieval from secondary memory

    Journal of Verbal Learning and Verbal Behavior

    (1970)
  • N. Burgess et al.

    Toward a network model of the articulatory loop

    Journal of Memory and Language

    (1992)
  • N. Burgess et al.

    A revised model of short-term memory and long-term learning of verbal sequences

    Journal of Memory and Language

    (2006)
  • A. Caramazza

    On drawing inferences about the structure of normal cognitive systems from the analysis of patterns of impaired performance: The case for single-patient studies

    Brain and Cognition

    (1986)
  • A. Caramazza et al.

    An investigation of repetition and language processing in a case of conduction aphasia

    Brain and Language

    (1981)
  • A. Caramazza et al.

    The selective impairment of phonological processing in speech production

    Brain and Language

    (2000)
  • R. Conrad

    Order error in immediate recall of sequences

    Journal of Verbal Learning and Verbal Behavior

    (1965)
  • F.I.M. Craik

    Two components in free recall

    Journal of Verbal Learning and Verbal Behavior

    (1968)
  • F. Friedrich et al.

    Interruption of phonological coding in conduction aphasia

    Brain and Language

    (1984)
  • M. Glanzer et al.

    Two storage mechanisms in free recall

    Journal of Verbal Learning and Verbal Behavior

    (1966)
  • M. Glanzer et al.

    Short-term storage in the processing of text

    Journal of Verbal Learning and Verbal Behavior

    (1981)
  • T. Hartley et al.

    A linguistically constrained model of short-term memory for nonwords

    Journal of Memory and Language

    (1996)
  • T. Hartley et al.

    Effects of rhythm on memory for spoken sequences: A model and tests of its stimulus-driven mechanism

    Cognitive Psychology

    (2016)
  • R.N. Henson

    Short-term memory for serial order: The start-end model

    Cognitive Psychology

    (1998)
  • R.J. Jarvella

    Syntactic processing of connected speech

    Journal of Verbal Learning and Verbal Behavior

    (1971)
  • M. Koenigs et al.

    Areas of left perisylvian cortex mediate auditory–verbal short-term memory

    Neuropsychologia

    (2011)
  • A.R. Luria et al.

    Towards a neurodynamic analysis of memory disturbances with lesions of the left temporal lobe

    Neuropsychologia

    (1967)
  • S. Majerus et al.

    The heterogeneity of verbal short-term memory impairment in aphasia

    Neuropsychologia

    (2015)
  • A.W. Melton

    Implications of short-term memory for a general theory of memory

    Journal of Verbal Learning and Verbal Behavior

    (1963)
  • L. Nickels et al.

    Fractionating the articulatory loop: Dissociations and associations in phonological recoding in aphasia

    Brain and Language

    (1997)
  • M.P. Page et al.

    Speech errors and the phonological similarity effect in short-term memory: Evidence suggesting a common locus

    Journal of Memory and Language

    (2007)
  • B.R. Postle

    Working memory as an emergent property of the mind and brain

    Neuroscience

    (2006)
  • C. Ranganath et al.

    Doubts about double dissociations between short-and long-term memory

    Trends in Cognitive Sciences

    (2005)
  • E.M. Saffran et al.

    Immediate memory for word lists and sentences in a patient with deficient auditory short-term memory

    Brain and Language

    (1975)
  • D.A. Allport

    Auditory-verbal short-term memory and aphasia

  • A. Awh et al.

    Dissociation of storage and rehearsal in verbal working memory: Evidence from positron emission tomography

    Psychological Science

    (1996)
  • A.D. Baddeley

    Short-term memory for word sequences as a function of acoustic, semantic and formal similarity

    Quarterly Journal of Experimental Psychology

    (1966)
  • A.D. Baddeley

    The influence of acoustic and semantic similarity on long-term memory for word sequences

    Quarterly Journal of Experimental Psychology

    (1996)
  • Baddeley A.D., Working memory, 1986, Oxford University Press;...
  • A.D. Baddeley

    The development of the concept of working memory: Implications and contributions of neuropsychology

  • A.D. Baddeley et al.

    The phonological loop as a language learning device

    Psychological Review

    (1998)
  • A.D. Baddeley et al.

    Working memory

  • A. Baddeley et al.

    Sentence comprehension and phonological memory: Some neuropsychological evidence

  • J.V. Baldo et al.

    Brain regions underlying repetition and auditory-verbal short-term memory deficits in aphasia: Evidence from voxel-based lesion symptom mapping

    Aphasiology

    (2012)
  • R.S. Berndt et al.

    Auditory and lexical sources in immediate recall: Evidence from a patient with deficit to the phonological short-term store

  • M.M. Botvinick et al.

    Short-term memory for serial order: A recurrent neural network model

    Psychological Review

    (2006)
  • B.R. Buchsbaum et al.

    The search for the phonological store: From loop to convolution

    Journal of Cognitive Neuroscience

    (2008)
  • N. Burgess et al.

    Memory for serial order: A network model of the phonological loop and its timing

    Psychological Review

    (1999)
  • B. Butterworth et al.

    Short-term retention without short-term memory

  • D. Caplan et al.

    Short-term memory and comprehension: A critical review of the neuropsychological literature

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