Sentence processing in the face of semantic loss: A case study.

The modularity of the sentence processor, or lack thereof, remains a much-debated issue in psycholinguistics. The authors present evidence from a semantically impaired patient (DM) that bears on this issue. As demonstrated elsewhere (S. D. Breedin, E. M. Saffran, & H. B. Coslett, see record 1996-90000-001), DM suffered a significant loss of semantic knowledge. Here, the authors show that this impairment did not compromise DM's ability to process syntactic information. DM performed well on grammaticality judgment tasks and on sentence comprehension tasks that required the use of syntactic information for the assignment of thematic roles. The resistance of syntactic operations to semantic loss would seem to pose a challenge for models in which "the syntactic and conceptual aspects of processing are … inextricably intertwined" (J. L. McClelland, M. St. John, & R. Taraban, see record 1991-26409-001, p. 329). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constructing naive theories of motion on the fly

People often make erroneous predictions about the trajectories of moving objects. McCloskey (1983a, 1983b) and others have suggested that many of these errors stem from well-developed, but naive, theories of motion. The studies presented here examine the role of naive impetus theory in people's judgments of motion. Subjects with and without formal physics experience were asked to draw or select from alternatives the trajectories of moving objects that were presented in various manners. Results from two experiments indicate that both trajectory judgments and explanations were affected by specific response and display features of the problem. In addition, these data provide little evidence that naive impetus theory plays a significant role in subjects' performance; instead, they suggest that motion judgments and explanations are constructed on the fly from contextual cues and knowledge that is not necessarily naive.