Accessing words in speech production: stages, processes and representations.

This paper introduces a special issue of Cognition on lexical access in speech production. Over the last quarter century, the psycholinguistic study of speaking, and in particular of accessing words in speech, received a major new impetus from the analysis of speech errors, dysfluencies and hesitations, from aphasiology, and from new paradigms in reaction time research. The emerging theoretical picture partitions the accessing process into two subprocesses, the selection of an appropriate lexical item (a "lemma") from the mental lexicon, and the phonological encoding of that item, that is, the computation of a phonetic program for the item in the context of utterance. These two theoretical domains are successively introduced by outlining some core issues that have been or still have to be addressed. The final section discusses the controversial question whether phonological encoding can affect lexical selection. This partitioning is also followed in this special issue as a whole. There are, first, four papers on lexical selection, then three papers on phonological encoding, and finally one on the interaction between selection and phonological encoding.     

Reaction time to threat stimuli in panic disorder and social phobia

Two studies assessed response time among clinically anxious subjects and normal controls when presented with threat, positive and neutral stimuli under perceptual (lexical decision) and semantic (category decision) task conditions. In Study 1, panic disorder subjects' (n = 14) performance was compared to that of matched normal controls (n = 14) while in Study 2 social phobic subjects (n = 24) were compared to matched normal controls (n = 24). Relative to matched normal controls, panic disorder subjects but not social phobics tended to show greater slowing in performance on the more cognitively complex (category) task. A second finding, consistent across both studies was that, compared to the normal control groups, both panic and social phobic groups showed significantly slowed responses to threat words in both the perceptual and semantic tasks. Such findings are directly counter to the predictions of a mood congruence hypothesis. This apparent contradiction is resolved by a review of the literature which indicates that mood-related facilitation effects are obtained only in tasks which tap awareness of threat information rather than speed of response. It is suggested that while anxiety may produce enhanced awareness of threat, it may inhibit responsiveness to it. The results of these studies are seen as consistent with ethological theories of inhibited motoric responses under certain threat conditions. Furthermore, the findings suggest that caution is indicated in interpreting slowed reaction time to threat stimuli in tasks such as the Stroop color naming task as purely the result of attentional processes.     

EFFECTS OF SELF-EVALUATION ON PRESCHOOL CHILDREN'S USE OF SOCIAL INTERACTION STRATEGIES WITH THEIR CLASSMATES WITH AUTISM

This study investigated effects of a self-evaluation procedure on preschool children's use of social interaction strategies among their classmates with autism. Three triads of children (comprised of 1 trained normally developing peer, 1 untrained peer, and 1 child with autism) participated. A multiple baseline design across subjects was used to demonstrate that peers who were taught facilitative strategies increased their use of strategies only after the self-evaluation intervention was introduced. Improvements in social behavior of children with autism was associated with peers' increased strategy use. Untrained peers demonstrated little change in their social behavior. Treatment effects were replicated when trained peers were asked to use self-evaluation with other children with autism during other play times. Self-evaluation procedures enhanced the use of social interaction strategies on the part of normally developing peers during social skills interventions.