Comprehending negation: A study with adults diagnosed with high functioning autism or Asperger's syndrome

Abstract

We investigated whether readers with high-functioning autism or Asperger's syndrome (HA/AS) differ from normal controls with respect to pragmatic aspects of negation processing. We presented short stories to two groups of readers, a group of individuals diagnosed with HA/AS and a group of normal controls. The final sentence of each story either affirmed or negated a particular proposition, which in the pragmatically felicitous context corresponded to a highly plausible assumption for the situation at hand, but in the pragmatically infelicitous context to an implausible assumption. In line with our predictions, the group of healthy controls read the negative but not the affirmative target sentences more slowly in the pragmatically infelicitous than in the pragmatically felicitous contexts. In the pragmatically felicitous context, reading times for negative sentences were as fast as those for affirmative sentences. In contrast, for the clinical group, the context had no effect: Reading times for the negative target sentences were longer than those of the affirmative target sentences in both context versions. These results indicate that individuals with HA/AS indeed differ from normal controls with respect to negation processing. Moreover, these results are in line with the more general hypothesis that the differences between normal individuals and those with HA/AS concern pragmatic aspects of language processing.