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Biomedical subjects

V A Thompson

Publications and source records attributed to V A Thompson.

4 recordsLinked to original sources

Perceived necessity explains the dissociation between logic and meaning: the case of "only if".

The purpose of this article was to investigate why sentences of the form "p only if q" often appear to have a different meaning than sentences of the form "if p, then q," despite their logical equivalence. The results of 3 experiments indicate that when "if ... then" statements were equated with respect to necessity and temporal relations, different pragmatic relations (such as permission, causation, etc.) elicited similar "only if" judgments. However, different necessity relations elicited different "only if" judgments, regardless of the type of pragmatic relation expressed in the "if then" statement. These data suggest that "only if" judgements are primarily mediated by necessity and temporal relations and that pragmatic contexts may play a more indirect role, such as in the interpretation of necessity and temporal relations. Suggestions for how these findings might be incorporated into pragmatic schema theory (P. W. Cheng & K. J. Holyoak, 1985; P. W. Cheng, K. J. Holyoak, R. E. Nisbett, & L. M. Oliver, 1986) and mental models theory (P. N. Johnson-Laird & R. M. J. Byrne, 1991) are discussed.

Dissociative Disorders

Memory for pictures and sounds: independence of auditory and visual codes.

Three experiments examined the mnemonic independence of auditory and visual nonverbal stimuli in free recall. Stimulus lists consisted of (1) pictures, (2) the corresponding environmental sounds, or (3) picture-sound pairs. In Experiment 1, free recall was tested under three learning conditions: standard intentional, intentional with a rehearsal-inhibiting distracter task, or incidental with the distracter task. In all three groups, recall was best for the picture-sound items. In addition, recall for the picture-sound stimuli appeared to be additive relative to pictures or sounds alone when the distracter task was used. Experiment 2 included two additional groups: In one, two copies of the same picture were shown simultaneously; in the other, two different pictures of the same concept were shown. There was no difference in recall among any of the picture groups; in contrast, recall in the picture-sound condition was greater than recall in either single-modality condition. However, doubling the exposure time in a third experiment resulted in additively higher recall for repeated pictures with different exemplars than ones with identical exemplars. The results are discussed in terms of dual coding theory and alternative conceptions of the memory trace.

Auditory Perception

Interpretational factors in conditional reasoning.

Two experiments examined the role of necessity and sufficiency relationships in conditional reasoning. The results indicated that perceived necessity and sufficiency predicted variability in reasoning performance for four pragmatic relations (permission, obligation, causation, and definition), for both determinant and indeterminant syntactic forms, and for both a conditional arguments and a truth table evaluation task, as well as when the temporal relationship between the antecedent and consequent events was reversed. These data support the general utility of perceived necessity and sufficiency in the interpretation and evaluation of conditional relationships. However, the effects of necessity and sufficiency were smaller for reversed than for forward statements, which suggests that necessity/sufficiency-based interpretations may be more useful for evaluating some types of conditional relations than others. In addition, people were more likely to accept valid rather than invalid arguments, regardless of necessity/sufficiency relations, a finding that suggests that abstract, content-free representations may play a functional role in conditional reasoning.

Cognition