Judgments of semantic anomaly in agrammatic patients: argument movement, syntactic complexity, and the use of heuristics.
Two studies on the judgment of semantic anomaly of sentences in agrammatic aphasia are reported. The primary question was whether performance on this task would be negatively affected by sentence complexity. In a first experiment, we repeated part of the study by Schwartz, Linebarger, Saffran, and Pate (Language and Cognitive Processing, 2, 85-113, 1987). With a group of 15 Dutch-speaking agrammatics, we obtained a small but significant negative effect of "lexical padding": sentences like "#the puppy ran around excitedly and accidently dropped the little boy onto the wet grass which upset Louise" elicited more errors than their simple counterparts, "#the puppy dropped the little boy." In our second study, we looked at (a) the effect of sentence embedding (e.g., "the doctor, who was tired of climbing a staircase, examined the patient") and (b) the effect of incorporating a "distractor agent" in the sentences, that is, an NP that could serve as a possible agent of the critical action (e.g., "the doctor, who had talked to the nurse, examined the patient"). In addition we employed sentences with moved arguments (e.g., "it was the patient who the doctor examined"). There were two major conclusions. First, syntactic complexity has a strong negative effect on anomaly judgments. Second, patient use a linear-order strategy to deal with the task. Results are discussed in terms of a range of recent approaches to agrammatic comprehension, not only representational hypotheses, based upon linguistic theory, but also processing accounts.