Recent behavioral evidence suggests that human vocabulary acquisition processes and verbal short-term memory abilities may be related (Gathercole & Baddeley, 1993). Investigation of this relationship has considerable significance for understanding of human language, of working memory, and of the relationship between short- and long-term memory systems. This paper presents a computational model of word learning, nonword repetition, and immediate serial recall. By providing an integrated account of these three abilities, the model provides a specification of how the mechanisms of immediate serial recall may be related to mechanisms of language processing more generally. Furthermore, the model provides fresh insight into the observed behavioral correlations between word teaming and immediate serial recall. According to the model, these correlations can arise because of the common dependence of these two abilities on core phonological and semantic processing mechanisms. This contrasts with the explanation proposed in the working memory literature, viz., that word learning is dependent on verbal short-term memory (Gathercole et al., 1992). It is discussed how both explanations can be reconciled in terms of the present model.

It is widely held that there is a distinction between attentive and automatic cognitive processing. In research on attention using visual search tasks, the detection performance of human subjects in consistent mapping paradigms is generally regarded as indicating a shift, with practice, from serial, attentional, controlled processing to parallel, automatic processing, while detection performance in varied mapping paradigms is taken to indicate that processing remains under attentional control. This paper proposes a priority learning mechanism to model the effects of practice and the development of automaticity, in visual search tasks. A connectionist simulation model implements this learning algorithm. Five prominent features of visual search practice effects are simulated. These are: 1) in consistent mapping tasks, practice reduces processing time, particularly the slope of reaction times as a ftinction of the number of comparisons; 2) in varied mapping tasks, there is no change in the slope of the reaction time function; 3) both the consistent and varied effects can occur concurrently; 4) reversing the target and distractor sets produces strong interference effects; and 5) the benefits of practice are a function of the degree of consistency.

The paradigm of immediate serial recall (Baddeley, 1986) has been used extensively in investigation of working m e m o r y , but its relation to and implica- tions for the nature of phonological processing have seldom been examined. W e show thatfindings from this domain can be interpreted in two ways, and relate these two interpretations to a simple model of phono- logical processing. One interpretation emphasizes the availability of infonnation from "output" phono- logical processing to "input" phonological process- ing, while the alternative account stipulates no such connections. On the basis of an experimental study designed to choose between the two accounts, w e tentatively conclude that the interpretation suggest- ing output-input connectivity is supported. Estab- lishment of this result would be of considerable in- terest, since it indicates that processes in language production can impact directly on processes in lan- guage perception.