TACIT INTEGRATION AND REFERENTIAL STRUCTURE IN THE LANGUAGE COMPREHENSION OF APHASICS AND NORMALS

Aphasics, brain-damaged patients with no language deficit, neurologica lly intact elderly subjects, and university undergraduates matched pic tures to sentences having compelling tacit implications (e.g., the sen tence The fox grabs the hen strongly invites one to assume that the fo x will eat the hen). All groups made, for the same sentences, qualitat ively similar referential errors consisting in choosing a tacit implic ation picture. Two auxiliary experiments using the same target sentenc es in other interpretive situations permitted ruling out the possibili ty that these errors were due to the putative intrinsic semantic prope rties of the sentences, showing that the sentences which were most lia ble to elicit integrative error varied from task to task These results are interpreted within the conceptual framework which posits that rel iable directions for interpretation are couched by the speaker in the very structure of his utterances (the utterance's referential structur e) providing the hearer with means to restructure the relevant persona l knowledge integrated into the interpretive process in accordance wit h the speaker's communicative intent The determination of the referent ial structure (RSD) of utterances thus seems critical to their correct or, more precisely, conventional interpretation, and, along with the tacit integration of relevant sources of personal knowledge, constitut es the principal cognitive device enabling us to understand each other . But this device appears to be easily corruptible. It is suggested th at many errors made by aphasics in language interpretation are due to a failure to follow an referential instructions, but that qualitativel y similar failures also occur in normal subjects, though to a lesser d egree. Language interpretation is a fallible process and aphasic error s provide remarkable clues for the understanding of its subtle referen tial mechanisms.