Biomedical subjects
Publications and source records attributed to H Gardner.
We challenge the position that only the analysis of single patients can allow us to infer normal function from impaired performance. We claim that the focus on group vs. single case studies is unprofitable and that a more useful question is how best to form abstractions of relevance to cognitive theory. In this context, we consider issues concerning the category of "agrammatism."
This study looked at the verbal interaction between mothers and their offspring with phonological disorders (age 3;6-5;1 years) who otherwise had language development within normal limits. This interaction was compared to two groups of mothers with children who were developing all aspects of language normally. There were eight subjects in each of the three groups: the phonologically disordered children (PDC), a group matched for age and language ability (AMG) and a group of children under 3 years (YCG) with age appropriate phonological development. Audio tapes were transcribed and percentage frequencies of certain verbal behaviours in both adult and child were calculated. The mother-child interaction of the phonologically disordered group was found to differ significantly from that of the peer group and more closely to resemble that of the younger normally developing children and their mothers.
We have previously reported the presence of a variant of human papillomavirus (HPV) type 11 in a nasal inverting papilloma [Respler et al., 1987]. In the present study, we have cloned molecularly the DNA of this variant at its unique restriction enzyme Bam HI site into lambda BF101 phage. Restriction enzyme mapping and DNA sequencing revealed that the genome of this virus contained an extra 531 base pair (bp) which was the repeat of most of the noncoding region (ncr) of HPV 11. Insertion of transcriptional control elements, including the repeated sequence, in front of the chloramphenicol acetyltransferase (CAT) gene resulted in a 5- to 30-fold increase in expression in transfected cells, as compared to the constructs containing a single ncr of HPV 11. This increased expression was due to enhanced levels of CAT RNA the synthesis of which is initiated by the viral promoter element.
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Right hemisphere brain-damaged (RHD) patients and healthy elderly and younger control subjects were tested on a battery of tasks designed to probe their script knowledge. More specifically, their ability to access and organize script information was assessed under conditions that varied in information-processing demands. For this purpose, two types of script tasks were employed: free response tasks, for which subjects had to structure their own responses, and constrained response tasks, in which subjects had to choose the better of two possible responses. All RHD patients tested had shown impairments on other narrative tasks. Subjects were asked to produce the sequences of steps which comprise two common activities and to provide continuations for segments of scripts (free-response tasks); they also were required to judge script element membership, temporal order, and relative importance (constrained-response tasks). The RHD patients and elderly and control subjects demonstrated a generally preserved knowledge of script information on all tasks. However, because of variability in the response style from the RHD patients and elderly subjects on free-response tasks, individual cases were examined. Several RHD patients' script productions were characterized by tangentiality while other patients showed a tendency to terminate their script productions prematurely. Four of ten elderly subjects produced highly personalized scripts. The relation of performance on these tasks to other documented narrative impairments is considered.
The inferential reasoning ability of right hemisphere-damaged (RHD) patients was tested by presenting pairs of sentences which were to be treated as single, integrated units. The two sentences treated together made one interpretation likely (a correct inference); one of the sentences in isolation encouraged a different interpretation (an incorrect inference). The position of the misleading sentence was systematically varied. Results showed that, in contrast to normal controls, RHD patients have more trouble answering inference questions, especially those concerning incorrect inferences, than answering questions about the factual content of the passages. Also, RHD patients made significantly more errors when the misleading information was contained in the first rather than in the second sentence; this finding indicates that these patients have difficulty revising previously acquired knowledge in light of new information. These results suggest the impairment of several components of normal discourse processing subsequent to right hemisphere brain damage.
Right hemisphere-damaged (RHD) and left hemisphere-damaged (LHD) aphasic patients were tested on a nonverbal cartoon completion task that included a humorous (Joke) and a nonhumorous (Story) condition. In both conditions, RHD patients performed worse than LHD patients. More importantly, the qualitative difference between the errors produced by the two groups suggests that right and left hemisphere brain damage impairs different components of narrative ability. RHD patients showed a preserved sensitivity to the surprise element of humor, and a diminished ability to establish coherence. Conversely, LHD patients, when they erred, showed an impaired sensitivity to the surprise element of humor, and a preserved ability to establish coherence by integrating content across parts of a narrative. These results suggest that the observed humor comprehension deficits of RHD patients result specifically from right hemisphere disease and not from brain damage irrespective of locus. The performances of the RHD and LHD patients groups together support a separation of narrative ability from the traditional aspects of language ability typically disrupted in aphasia.
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Sets of words can be grouped in terms of their denotation (cold and warm both refer literally to temperature) or in terms of their connotation (cold and warm connote remoteness and intimacy, respectively). To assess whether these two facets of meaning are dissociable, unilaterally left- and right-hemisphere-damaged patients were presented with word triads and asked to group together the two words that were closest in meaning. Right-hemisphere-damaged patients showed a preserved sensitivity to denotation, and a selective insensitivity to connotative facets of meanings. In contrast, left-hemisphere-damaged patients exhibited a preserved sensitivity to connotation as well as a selective insensitivity to denotative aspects of meanings. Inasmuch as normal control subjects displayed a flexible sensitivity to both denotative and connotative aspects of meaning, the results suggest that unilateral brain damage selectively curtails use of one or the other major aspect of word meaning.
Verbal humor deficits were investigated in right-hemisphere-damaged patients. It was hypothesized that the appreciation of jokes presupposes two elements: sensitivity to the surprise element entailed in the punch line of a joke and apprehension of the coherence which results when the punch line has been integrated with the body of the joke. The possible dissociation between these elements was tested by asking subjects to select from four alternatives the appropriate ending to a joke. Right-hemisphere patients exhibited a selective attraction to endings which contained an element of surprise but which were not otherwise coherent with the body of the joke. This finding suggests that right-hemisphere patients have difficulty in integrating content across parts of a narrative and confirms the psychological reality of the proposed distinction between the surprise and coherence elements of humor processing.
Patients with unilateral right-hemisphere lesions performed significantly worse than normal controls in arranging the mixed-up sentences of stories. This impairment was not restricted to paragraphs conveying primarily spatial information, but occurred on other types of paragraphs as well. Nonspecific deficits of brain injury were ruled out as possible alternative explanations for the patients' difficulty on the task. The organization of language at the paragraph level may depend on right-hemisphere functioning.
A 77-year-old composer had a left occipital lobe haemorrhagic infarct giving a severe reading disturbance with well-preserved writing and without appreciable aphasia. He continued to read music and to compose. His text- and music-reading performance under different conditions suggests that this unusual dissociation was primarily due to four factors. (1) He was unusually talented musically and inferred a great deal about the music he was reading. (2) The symbols of staff music notation are more visually distinctive than the symbols of phonetic language writing systems. (3) In staff music notation, pitch is represented ordinally, and other symbols are also distinguishable by their relative positions and sizes. (4) Music notation can be usefully read by interpreting it acoustically, kinaesthetically or in terms of formal musical concepts; in contrast to written language, it need not be interpreted referentially or in terms of auditory-verbal images. His disorder fits the classic visual-verbal disconnection account of alexia without agraphia and the contemporary view that music involves a family of related but distinct skills probably involving many brain areas in both hemispheres, although different cortical areas make characteristic contributions to different musical behaviours.
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