The impact of the lexicality of memory items on memory performance was compared in two paradigms, serial recall and serial recognition. Experiments 1 to 3 tested 7- and 8-year-old children. Memory accuracy was only mildly impaired in lists containing nonwords compared with words in a serial recognition task involving judgments of whether the items in two sequences were in the same order (Experiment 1), although a substantial advantage for word over nonword items from the same stimulus pool was found in serial recall (Experiment 2). A stronger influence of lexicality on serial recall than serial recognition was further demonstrated in Experiments 3A and 3B, and in 4A and 4B using adult participants. These experiments also established comparable degrees of sensitivity to the phonological similarity of the memory sequences in the two paradigms. The phonological similarity effect in serial recall was found to arise from increased phoneme order errors, whereas the lexicality effect was due principally to the greater frequency of phoneme identity errors for nonwords. It is proposed that the lexicality effect originates in the redintegration of item information just prior to recall, and that this process is largely bypassed in serial recognition.

Evidence from a number of sources now suggests that the visuo-spatial sketchpad (VSSP) of working memory may be composed of two subsystems: one for maintaining visual information and the other for spatial information. In this paper we present three experiments that examine this fractionation using a developmental approach. In Experiment 1, 5-, 8-, and 10-year old children were presented with a visuo-spatial working memory task (the matrices task) with two presentation formats (static and dynamic). A developmental dissociation in performance was found for the static and dynamic conditions of both tasks, suggesting that the activation of separable subsystems of the VSSP is dependent upon a static/dynamic distinction in information content rather than a visual/spatial one. A highly similar pattern of performance was found for a mazes task with static and dynamic formats. However, one strategic activity, the use of simple verbal recoding, may also have been responsible for the observed pattern of performance in the matrices task. In Experiments 2 and 3 this was investigated using concurrent articulatory suppression. No evidence to support this notion was found, and it is therefore proposed that static and dynamic visuo-spatial information is maintained in working memory by separable subcomponents of the VSSP.Understanding the processes involved in the maintenance of information in memory for short periods of time owes much to the working memory model (Baddeley, 1986;Baddeley & Hitch, 1974). According to this model, visuo-spatial information is maintained in a slave system known as the visuo-spatial sketchpad. The activity of this and the other slave system, the phonological loop, is controlled by a further component, the central executive. Although many aspects of working memory relating to phonological loop function are now well understood, less is known about the workings of the visuo-spatial sketchpad. In particular, whereas the Requests for reprints should be sent to Susan J. Pickering,

Evidence from a number of sources now suggests that the visuo-spatial sketchpad (VSSP) of working memory may be composed of two subsystems: one for maintaining visual information and the other for spatial information. In this paper we present three experiments that examine this fractionation using a developmental approach. In Experiment 1, 5-, 8-, and 10-year old children were presented with a visuo-spatial working memory task (the matrices task) with two presentation formats (static and dynamic). A developmental dissociation in performance was found for the static and dynamic conditions of both tasks, suggesting that the activation of separable subsystems of the VSSP is dependent upon a static/dynamic distinction in information content rather than a visual/spatial one. A highly similar pattern of performance was found for a mazes task with static and dynamic formats. However, one strategic activity, the use of simple verbal recoding, may also have been responsible for the observed pattern of performance in the matrices task. In Experiments 2 and 3 this was investigated using concurrent articulatory suppression. No evidence to support this notion was found, and it is therefore proposed that static and dynamic visuo-spatial information is maintained in working memory by separable subcomponents of the VSSP.

Postevent misleading information can distort people's memories by altering and adding scenes. But can you also inhibit the retrieval of information from memory? In two studies we show that postevent information can make memory for a scene less accessible. In both studies participants ®rst saw an event (e.g. a restaurant scene displayed in slides, or a drunk-driving incident shown via a video clip). Later they were shown the same event without a critical scene and were told either to use this to generate a story (Experiment 1) or to imagine the event (Experiment 2). Finally they were tested. Relative to controls, this postevent omission led to fewer people reporting the critical scene in free recall and in recognition. Thus, we demonstrated that it may be possible to inhibit memories. This ®nding has important implications for eyewitness testimony and the recovered memory debate.

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