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 shortterm verbal memory are shown to account for many of the observed effects of presentation modality. Penney (1975) reviewed the literature on the effects of presentation modality on short-term retention of verbal material and concluded that there were separate stores for auditorily and visually presented information. To emphasize the idea that active processing underlies retention in short-term memory, and to discourage the conceptualization of short-term memory as a warehouse of decaying information, Penney (1980) introduced the term separate processing streams to replace the notion of separate memory stores. Since publication of the review paper, additional work on modality effects has supported the hypothesis of modality separation in the processing of verbal material in short-term memory (the separate-streams hypothesis), and new findings have elucidated the nature of the separate processing streams. The present paper is a review of the literature on modality effects and related phenomena, with the goal of presenting an integrated account in terms of the different properties and capabilities of the separate processing streams. These processing streams are seen to reflect the inherent structure of short-term verbal memory, and not to represent strategic processes.In 1975, the term modality effect referred to the finding that, in short-term memory tasks, auditory presentation almost always resulted in higher recall than did visual presentation. This modality effect was found for the recency part of the serial position curve in immediate free recall and in serial recall, and the auditory superiority was also found in the Peterson distractor task, provided that I would like to thank Donald Broadbent, Robert Crowder, Susan Manning, Bennet Murdock, James Nairne, Lars-Goran Nilsson, Charles Thompson, and Michael Watkins for their helpful comments on earlier drafts of the paper. Reprint requests may be addressed to the author, Psychology Department, Memorial University of Newfoundland, St. John's, Newfoundland AlB 3X9, Canada. the distraction did not require a long period of vocalization. Overt vocalization of a visually presented list by the subject produced much the sa...

For short-term memory, auditory presentation is consistently superior to visual presentation, with the difference restricted to recently presented items. Recall increases with fast presentation rates when auditory presentation is used in a serial recall task; otherwise, recall decreases as presentation rate increases. Some puzzling findings on dichotic and bisensory split-span memory are shown to be related to aspects of the modality difference, notably the strong sequential associations in auditory memory.Recently in the area of short-term memory, a number of investigators have reported differences in recall as a function of auditory and visual presentation of verbal items. Modality differences have been reported in every short-term memory task investigated, a finding which suggests that modality effects deserve more attention. There are few variables in the study of memory which have shown such a consistent effect across a variety of tasks. Furthermore, modality effects in long-term memory have not been reliably demonstrated. As Tulving and Madigan (1970) pointed out, the disappearance of the modality effect when longer retention intervals are used poses a problem for certain theories. For these reasons, it has become apparent that a thorough review of the literature on modality effects should be undertaken with a view to examining some of the theoretical implications.Experimental comparisons of auditory and visual presentation and the theoretical interpretations of any differences found are complicated by the lack of equivalence of auditory and visual stimuli. For example, it is difficult to vary the effective presentation time of auditory stimuli to correspond with visual presentation times of 2 or 3 sec. Other examples can easily be found. The usual procedure is to ensure that both auditory and visualThe author would like to thank Edward Rowe for his comments on an earlier draft of the manuscript and Bennet Murdock for his help and encouragement.

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Many children and adults are poor readers and have difficulty decoding words from print. To achieve fast and effortless word identification a reader must understand how letter patterns map onto pronunciation and, for printed words that have not been previously encountered, must be able to produce an approximate pronunciation. If the approximate pronunciation can be mapped onto a known word, lexical and semantic information can then be retrieved. For many children the first step of learning associations between letter patterns and pronunciation is difficult and these children often do not develop adequate decoding skills. This article reports an experimental investigation of a technique designed to teach decoding skills to a group of high school students with reading difficulties.The technique investigated was based on the Glass

The effects of suffix delay on recall of terminal and preterminal list items was investigated in two experiments. A presentation rate of 0.4 s/item was used for list items, and suffix delay varied from 0.4 to 1.0 s. In the first experiment, suffix condition varied randomly throughout the experimental session; in the second experiment, all trials on a particular suffix condition were blocked together. Recall of the terminal item increased in a linear fashion with suffix delay, but there was no effect of suffix delay on preterminal items. The results are interpreted as supporting Penney's (1985) two-mechanisms account of the suffix effect.Resume Les effets de d£lai du suffixe sur le rappel d'une liste d'items terminaux et preterminaux ont 6t£ investigue's lors de deux experiences. Un taux de presentation de 0.4 s/item a 6t6 utilise pour une liste d'items et le delai du suffixe variait de 0.4 a 1.0 s. Dans la premiere experience, la condition du suffixe variait au hasard pendant toute la session expeiimentale; dans la deuxieme experience, tous les essais d'une condition de suffixe particuliere dtaient mis ensemble. Le rappel de l'item terminal augmentait de facon lindaire avec le d61ai du suffixe; il n'y avait cependant pas d'effet de delai du suffixe sur les items pr&erminaux. Les resultats vont dans le sens de 1'hypothese de Penney (1985) sur les deux mecanismes de l'effet du suffixe.The suffix effect is a well established phenomenon in short-term memory. The stimulus suffix is a verbal item appended to a short list of letters, words, or digits that is usually to be recalled immediately after presentation in the correct order. Typically, the subject is instructed that (a) the suffix serves to mark the end of the list, (b) the suffix is the same word on each trial and is compared to a tone or buzzer control, and (c) the suffix is not to be recalled. When both list and suffix are presented auditorily, the suffix has a large detrimental effect on recall of the last few list items with the greatest effect usually observed for the last memory item. Penney (1985) proposed two mechanisms underlying the suffix effect: a terminal suffix effect due to the loss of finality of the terminal