Wendy Wapner

The role of the right hemisphere in the apprehension of complex linguistic materials

Abstract To secure information on which aspects of linguistic functioning might be mediated by the nondominant hemisphere, a test battery assessing sensitivity to narrational and humorous materials was administered to a population of right-hemisphere-damaged patients, as well as relevant control groups of normal, aging, and aphasic individuals. While elementary linguistic functioning was adequate, the right-hemisphere-injured groups exhibited consistent difficulties in respecting the boundaries of a fictive entity, assessing the plausibility of elements within a story or joke, selecting the appropriate punch line for a joke, and integrating elements of a story into a coherent narrative. Certain elements—specifically emotional content and noncanonical facts injected into a narrative—also posed characteristic difficulties for these patients. The results suggest that, in contrast to the other populations, right-hemisphere patients exhibit special difficulties in processing complex linguistic entities and in utilizing the surrounding context as they assess linguistic messages.

Sensitivity to emotional expressions and situations in organic patients.

While numerous lines of investigation indicate the pivotal role of the right hemisphere in the apprehension and processing of emotional information, the specific contributions of facial recognition, other visual-spatial capacities, and a general understanding of emotionally-toned situations remains to be delineated. To secure information on the contributions of these various factors, matched groups of brain-damaged patients were required in a series of tests to match with one another faces of the same individual, facial expressions, pictorial versions of emotional situations, and linguistic versions of emotional situations. While patients with left-hemisphere damage evinced special difficulty with linguistically-presented stimuli, patients with right hemisphere damage exhibited an across-the-board reduction in emotional sensitivity, one not restricted to stimuli presented in the visual modality. In addition, right hemisphere patients also displayed a selective tendency to group together emotions of an opposite polarity (positively-toned with negatively-toned emotions). These results suggest that, in addition to its general importance in a range of emotional tasks, the right hemisphere is crucial for an appreciation of the structural relations which obtain among various emotions.

The relation between gesture and language in aphasic communication

Abstract Effective communication in aphasia depends not only on use of preserved linguistic capacities but also (and perhaps primarily) on the capacity to exploit alternative modalities of communication, such as gesture. To ascertain the capacity of aphasic patients to use gesture in their spontaneous communication, informally structured interviews were conducted with two Wernickes aphasics and two Brocas aphasics, as well as with four normal controls. The performances of the patient groups were compared on the physical parameters of gesture, the points in the communication where gestures occurred, and several facets of the semantics and pragmatics of gesture. Generally speaking, the gestures of the aphasics closely paralleled their speech output: on most indices, the performance of the Wernickes aphasics more closely resembled that of the normal controls. Wernickes aphasics differed from normals in the clarity of their language and gestures: While individual linguistic units were often clear, the relation among units was not. In contrast, the Brocas aphasics equaled or surpassed the normal controls in the clarity of their communications. The results offer little support for the view that aphasic patients spontaneously enhance their communicative efficacy through the use of gesture; these findings can, however, be interpreted as evidence in favor of a “central organizer” which controls critical features of communication, irrespective of the modality of expression.

Visual agnosia in an artist.

This report describes a 73 year old left-handed male artist who presented with agnosic symptoms following an occipital cerebral vascular accident. Against a background of a memory disturbance, but otherwise essentially intact linguistic and cognitive capacities, the patient was generally unable to identify single objects on visual presentation, and displayed marked difficulty in interpreting complex objects, depicted scenes, and partially occluded figures. The patients preserved ability to recognize geometric forms, to perceive optical illusions, and to copy designs, and objects with considerable accuracy suggested the clinical picture of visual agnosia. An examination was undertaken of the effects of this recognition disorder on the artists capacity to draw. Despite an inability to recognize an object or scene, the patient retained various techniques (perspective, shadowing, designation of texture) which allowed him to copy the display in a veridical fashion. When displays were recognized, or when the patient was given only the name of the object and asked to draw it, he adopted a less slavish approach, characteristic of his pre-morbid artwork. While his post-morbid drawings bore a strong similarity to his earlier works, such features as insufficient differentiation of figure from ground, over-elaboration of detail, and areas of neglect revealed the debilitating effects of the recognition disorder. Moreover, an examination of the patients strategies revealed numerous compensatory verbal and motor procedures which guided his drawing. Acknowledgments. We wish to acknowledge Dr. Prather Palmer, J.R.s neurologist, for his cooperation and for making available his very thorough examination notes. Thanks also to Dr. Kent Stevens for providing the stereograms, and to Dr. Frank Benson and Dr. Edgar Zurif for their helpful comments on the manuscript.

The appreciation of antonymic contrasts in aphasia.

Abstract To secure information on the ability of aphasic patients to comprehend antonymic relations, the kinds of confusions typically made, and the extent to which antonymic sensitivity depends upon mode of presentation and task demands, three linguistic and nonlinguistic tests were administered to aphasic patients, right hemisphere-damaged patients, and non-neurological controls. Although difficulty with antonymous relations was found among all the organic patients, the kinds of problems evidenced and the relative profile of difficulties differed across populations. Among the principal findings were the generally preserved sensitivity to antonymy found among anterior (particularly Brocas) aphasics; a surprising insensitivity to antonymy and a preference for synonyms, found among right hemisphere patients, particularly on the nonlinguistic tasks; a relative preservation of sensitivity to antonymy on nonlinguistic tasks, coupled with a loss of such sensitivity on linguistic tasks, found among posterior (particularly Wernickes) aphasics; a proclivity toward stereotypical correct responses among the organic patients; and an absolutely worse performance by right hemisphere patients on tasks involving antonymic relations in pictures and abstract designs.

A study of spelling in aphasia.

Abstract To secure systematic information on spelling abilities following damage to the dominant hemisphere, a test probing performance in three modalities of response was administered to a group of aphasic patients. Except for a predictable deficit among anterior aphasics in oral spelling, anterior and posterior aphasics exhibited comparable performances on the measures of spelling. However, anterior and posterior aphasics differed from one another on the kinds of words they most accurately spelled, the errors they were prone to make, and certain strategies which they characteristically adopted. These results suggest two alternative approaches to spelling: one approach, common in posterior aphasics, entails choosing letter combinations on the basis of their customary sounds; a second approach, common among anterior aphasics, appears to rely on a partially preserved image of the words appearance.

Profiles of symbol-reading skills in organic patients.

Abstract One (unitary) school of thought views all symbolic competences as closely related, while a rival (pluralistic) approach underscores the relative differences among modes of symbolic processing. To secure information on the plausibility of these competing hypotheses, matched groups of left- and right-hemisphere patients were given a visual symbol-recognition test. Subjects were required to choose the correctly depicted symbol among a set of four. The results challenge a strong version of the “unitary” hypothesis. What emerges instead is a view of symbol systems as a continuum: relatively linguistic symbol systems prove challenging for left-hemisphere patients, relatively nonlinguistic systems pose comparable difficulties for right-hemisphere patients. Contrary to hypothesis, the processing of numerical symbols poses special difficulty for right-hemisphere patients. Performance on trademarks—items which can be processed by linguistic or nonlinguistic strategies—suggests that organic patients with contrasting pathologies may adopt different processing strategies when confronting identical physical stimuli.