A linguistic deficit resulting from right-hemisphere damage

Abstract

The ability of right-brain-damaged (RBD) subjects to correctly insert a word into a well-formed stimulus sentence was tested. Subjects also performed three evaluative tasks designed to establish their degree of general cognitive impairment. The performance of RBD subjects on these tasks was compared to that of left-brain-damaged (LBD) and non-brain-damaged (NBD) subjects. Although RBD subjects outperformed LBD subjects on the language-related evaluative tasks, the RBD group was significantly more impaired on a subset of the insertion task. This subset included items which required reassignment of the syntactic status of elements in the stimulus sentence in order for the insertion to be carried out. The results of this study permit refinement of the common characterization of RBD individuals as rigid in their interpretation of meaning and indicate right-hemisphere involvement in aspects of the grammar previously thought to be inaccessible to it.

The Use of Contextual Information by Right Brain-Damaged Individuals in the Resolution of Ambiguous Pronouns

“…As noted by the authors, such a finding suggests that RBD patients may simply have more difficulty than normals in rejecting an initial interpretation. This inability of RBD individuals to reject contradictory elements has been observed previously (Wapner et al, 1981) and appears to parailel apparent sentence processing deficits observed by Schneiderman and Saddy (1988) who found that RBD individuals had difficulty reassigning the syntactic status of a word, as weil as the results of Ulatowska and Baker (1976) who found that RBD patients had difficulty rearranging words in an anagram task to forrn a different correct arrangement, once a fust solution was found.…”

“…Another interesting finding that emerged from the results of this experiment concemed the daim that RBD individuals have difficulty revising initial interpretations (e.g. Brownell et al, 1986;Schneiderman & Saddy, 1988;Ulatowska & Baker, 1976). In facto the results ofthis experiment suggested otherwise, at least with respect to the factor of implicit causality.…”

“…It appears that some of the sentence processing deficits demonstrated by RBD patients, such as difficulty solving syllogistic reasoning problems Grossman, 1982;Joanette et al, 1983) or arranging words in a sentence (Cavalli et al, 1981;Schneiderman & Saddy, 1988;Ulatowska & Baker, 1976), may he due to a difficulty in the manipulation of linguistic elements, rather than a parsing deficit per se. In view of the preceding discussion on automatic versus effortful processing, il may, indeed, he the case that the sentence processing difficulties exhibited by RBD patients are more a reflection of the effortful processing required in the tasks used, rather than a reflection of true syntactic deficits.…”

“…Evidence from a number of studies (e.g. Brownell et al, 1986;Schneiderman & Saddy, 1988;Ulatowska & Baker, 1976) has suggested that RBD individuals may be impaired in their ability to revise initial interpretations. For examp1e, in Brownell et al (1986), it was found that RBD patients exhibited difficulty in revising initial inferences that were based on misleading information once the informative information was encountered.…”

Dal suono alla parola

“…Schneidermann e Saddy (1988) in uno studio su pazienti destro-lesi rilevano che questi soggetti sembrano avere minore flessibilità nell'attribuzione di proprietà strutturali agli enunciati. Il test prevedeva l'interpretazione dell'enunciato "the boy hit the man with the cane" in questo caso "con la canna" può essere un'espressione qualificativa che descrive l'uomo colpito o un'espressione strumentale che precisa il modo in cui il ragazzo ha colpito l'uomo: i pazienti esaminati da Schneidermann e Saddy non riescono a vedere queste due possibilità interpretative.…”