Picture superiority in free recall: Imagery or dual coding?

The effects of auditory and visual presentation upon short-term retention of verbal stimuli are reviewed, and a model of the structure of short-term memory is presented. The main assumption of the model is that verbal information presented to the auditory and visual modalities is processed in separate streams that have different properties and capabilities. Auditory items are automatically encoded in both the A (acoustic) code, which, in the absence of subsequent input, can be maintained for some time without deliberate allocation of attention, and a P (phonological) code. Visual items are retained in both the P code and a visual code. Within the auditory stream, successive items are strongly associated; in contrast, in the visual modality, it is simultaneously presented items that are strongly associated. These assumptions about the structure of short-term verbal memory are shown to account for many of the observed effects of presentation morality.

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Modality effects and the structure of short-term verbal memory

Ten possible sources of individual and developmental differences in memory span—rehearsal, grouping, chunking, retrieval strategies, item identification, item ordering, capacity, susceptibility to interference, search rate, and the ouput buffer—arc examined, drawing on existing research, Considerable evidence suggests that the speed with which presented items can be identified is a major source of both individual and developmental differences in span, By contrast, there is no conclusive evidence that any of the other possibilities examined, including those traditionally associated with span differences (rehearsal, grouping, chunking, and overall information-processing capacity) contributes to variations in span. Speed of item identification differences are discussed in terms of processing efficiency or the capacity needed to activate appropriate perceptual/ cognitive units and linguistic programs. Educational implications and the modifiability of processing efficiency are discussed. The first recorded experiments on memory span were conducted by Ebbinghaus in 1885 (published in 1913) in his pioneering application of the scientific method to the study of the "higher mental processes." These experiments grew out of his investigation of the functional relation between the ease of learning a series and its length. Ebbinghaus found that the maximum number of items he could reproduce perfectly immediately following a single presentation—his span1— was generally seven, with remarkably few exceptions. Other studies fashioned after Ebbinghaus's procedures followed soon thereafter, and in the first review of the memory literature (Burnham, 1888-1889), several pages (607-609) were devoted almost exclusively

Memory Span: Sources of Individual and Developmental Differences

This paper evaluates the assertion that short-term memory (STM) capacity increases with age. Initially an analysis is made of the STM system in terms of its parameters and control processes. No evidence was found that can suggest conclusively that either the capacity or the rate of information loss from STM varies with age. On the other hand, substantial evidence exists to show that the processing strategies used by adults are unavailable or deficient in children. Furthermore, considerable differences in the contents and complexity of the long-term memory (LTM) knowledge base (semantic and recognition networks can produce grossly different STM performance between age groups. The second half of this paper reviews three STM-related paradigms—memory span, serial probed recall, and recognition under limited exposure—that have consistently shown performance deficits in children. These deficits are explained in terms of the lack of proper control processes (or processing strategies), as well as an impoverished LTM knowledge base rather than a limitation in STM capacity.

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Short-term memory limitations in children: Capacity or processing deficits?

Modality effects in short-term verbal memory.

Lists of six digits were presented either auditorially or visually at rates of 1, 2 or 3 digits/sec to groups of 7-, 8-, 9- and 10-year-old girls. Immediate recall improved with age under all conditions, but the recall of visually presented slow lists improved with age at a steeper rate than did the recall of visually presented fast lists or of auditorially presented lists. The results are related to the findings of previous studies on STM as a function of presentation rate, and in particular to the hypothesis that when slow rates give superior recall as compared with fast, it is because subjects can more fluently read and rehearse the items at the time of perception.

Visual and auditory presentation, presentation rate, and short‐term memory in children

Fifty babies, 24–48 h old, heard one of five sounds: human heart beats at 75 or 45 dB, a regularly intermittent tone of 55 cps at 75 or 45 dB, and ambient noise. Activity was reduced by the louder heartbeat sound. Respiration and heart rate were unchanged in all conditions. The results are consistent with the hypothesis that, for newborns, the sound of the heart is an especially effective pacifier.

/pdf/activity-in-newborns-and-the-sound-of-a-human-heart-2326j0yqxv.pdf

Beverley Roberts

Papers

Visual and auditory presentation, presentation rate, and short‐term memory in children

Activity in newborns and the sound of a human heart