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R H Logie

Publications and source records attributed to R H Logie.

4 recordsLinked to original sources

Recency, primacy, and memory: reappraising and standardising the serial position curve.

In this paper we consider the serial position curve in immediate verbal free recall. A large literature has argued that two components of the serial position curve, recency and primacy, reflect the functioning respectively of short-term and of long-term memory. However, there are a number of difficulties in interpreting the recency effect as a phenomenon uniquely associated with short-term memory. Moreover, the serial position curve has been used widely for clinical investigations in patients with memory deficits. This is despite the lack of norms for the measures derived from the curve. We present a set of standardised norms based on 321 Italian normal subjects. These norms are shown to be applicable both to an English speaking population, and to three groups of brain damaged-patients, namely Alzheimer's, amnesics, and frontals. The standardised norms offer a clinical and experimental tool which, coupled with a multiple single case approach, allows us to show dissociations and double dissociations among the performance patterns obtained from all three pathological groups. The paper concludes with a discussion of a possible interpretation of the recency effect as a emergent property of all types of memory system, including verbal short-term memory. Taking into account previous literature as well as our own data, the recency effect in immediate verbal free recall is here interpreted in terms of a two-component view of verbal short-term memory.

Adult

Case studies in working memory: a case for single cases?

Patterns of cognitive deficit in single neuropsychological cases are common sources of evidence for theories of normal cognition. In particular, the working memory model has benefited from data obtained from a number of contrasting patients, in some cases resulting in modifications of the working memory model. In this paper, patterns of data from short-term memory patients and anarthric patients are compared with patterns of data from normal subjects. The patterns of patient data that were unlike those patterns typically found for groups of normal subjects, could be incorporated within a modified version of the articulatory loop component of the working memory model. However a small number of individual normal subjects also did not show the pattern that is reported on the basis of average performance of groups of normal subjects. This causes some difficulty in interpreting those data from such 'aberrant normal' patterns, and those data from single patients with functional cognitive deficits. The implications of these findings for the interpretation of neuropsychological data are discussed in the context of the working memory model, but with the intention of making a general point pertaining to the development of functional models of cognition. It is argued that single case studies should continue to provide a useful source of evidence, providing that care is exercised in considering the implications of such data for models of normal cognition.

Adult

Interference with visual short-term memory.

Working memory (Baddeley and Hitch 1974) incorporates the notion of a visuo-spatial sketch pad; a mechanism thought to be specialized for short-term storage of visuo-spatial material. However, the nature and characteristics of this hypothesized mechanism are as yet unclear. Two experiments are reported which examined selective interference in short-term visual memory. Experiment 1 contrasted recognition memory span for visual matrix patterns with that for visually presented letter sequences. These two span tasks were combined with concurrent arithmetic or a concurrent task which involved manipulation of visuo-spatial material. Results suggested that although there was a small, significant disruption by concurrent arithmetic of span for the matrix patterns, there was a substantially larger disruption of the letter span task. The converse was true for the secondary visuo-spatial task. Experiment 2 combined the span tasks with two established tasks developed by Brooks (1967). Span for matrix patterns was disrupted by a visuo-spatial task but not by a secondary verbal task. The converse was true for letter span. These results suggest that the impairment in short-term visual memory resulting from secondary arithmetic reflects a small general processing load, but that the selective interference due to mode of processing is by far the stronger effect. Results are interpreted as being entirely consistent with the notion of a specialized visuo-spatial mechanism in working memory.

Adult