Biomedical subjects

J Wale

Publications and source records attributed to J Wale.

14 recordsLinked to original sources

PubMed1992

The effect of illness duration on perceptual asymmetry in schizophrenia.

Perceptual asymmetry in a group of schizophrenic subjects who were clinically stable and living in the community was compared with a group of normal control subjects matched for age and sex using a dichotic monitoring task of language processing. Schizophrenic subjects showed reduced target detection and slower reaction times for both left and right ear inputs. In relation to performance asymmetry, the schizophrenic subjects had a reduced speed of responding to left ear items compared to normal controls. Within the schizophrenic group differences in performance emerged according to duration of illness. Shorter duration of illness was associated with poorer target detection overall and comparatively greater magnitude of the normal right ear advantage. The latter was accounted for by a relative augmentation of the normal left ear performance decrement. These results were partly reflected in the reaction time measures. The findings suggest that as illness duration increases there may be a tendency for certain aspects of the information processing abnormality in schizophrenia to normalise, in spite of continued deficits as reflected in prolonged reaction times.

Adult↗

PubMed1990

Differences in dichotic listening asymmetries in depression according to symptomatology.

Subjects suffering from major depressive disorder were compared to normal controls on two verbal dichotic listening tasks. Although there were no significant differences between the groups on a task primarily of language perception, significant differences were obtained on a task with an attentional component. Overall performance was lower for the depressed group and ear asymmetry was reduced. Within the depressed group ear asymmetry varied according to symptomatology; withdrawal-retardation was associated with a lack of asymmetry and anxiety with a normal right ear advantage. The results were interpreted in terms of an interaction between affect and attention, and possible underlying mechanisms of cerebral hemisphere function were discussed.

Adolescent↗

PubMed1989

Focused and divided attention in each half of space with disconnected hemispheres.

The effects of spatial location and strategy of attention on the processing of speech messages were investigated in ten right-handed subjects and four persons with complete forebrain commissurotomy and one case of right hemispherectomy. Lists of simultaneous but different words, with one of each pair spoken by a male and the other by a female, were monitored for target words. The lists were presented to the left ear, the right ear and to both ears (central) in separate conditions. Unimanual responses were made to targets in either voice (divided attention) or to only one of the voices (focused attention). The performance of the clinical subjects was generally less efficient than that of the controls. In contrast to intact subjects, they responded to more distractor and unattended items. They also showed a nonsignificant tendency for better processing of right rather than centrally-presented words. With right-sided presentation two clinical subjects, with extracallosal damage to the right cortex, were unable to divide attention and responded to only one of the voices. These results implicate an intact corpus callosum for efficient use of attention strategies as well as hemispheric differences in the control of attention.

Adolescent↗

PubMed1988

Dichotic listening asymmetries and psychotic symptoms in schizophrenia: a preliminary report.

Schizophrenic subjects were compared with both psychiatric control and normal control groups on two verbal measures of functional hemispheric asymmetry on a dichotic listening task. One measure of language perception showed little variation in ear differences across groups. However, the task that contained both attentional and language-processing components showed variations in asymmetry according to symptomatology. Subjects with high scores on scales of hallucinations and delusions showed a pattern of ear differences that was not found in those with low scores on these symptom dimensions. The results may reflect cognitive factors in a dysfunctional information-processing system and, in particular, attentional disturbance rather than anomalies in the lateralization of language.

Adolescent↗

PubMed1988

Antibody response to outer-membrane antigens of Pseudomonas aeruginosa in human burn wound infection.

There is little information about the local and systemic antibody response to surface antigens of bacteria growing in situ in infected lesions in man. In this study, Pseudomonas aeruginosa was obtained directly from the infected wounds of two patients with burns and studied without subculture. Outer-membrane proteins (OMPs) were investigated and compared with those of cells cultivated in the laboratory, with the aim of selecting defined growth conditions to give surface antigens more closely resembling those found in vivo. Several high-mol. wt (77,000-101,000) proteins were expressed in the outer membranes of the bacteria from the patients and could be phenotypically induced by cultivating the same isolate in iron-depleted conditions in vitro. Other major OMPs (D, E, F, G and H) were also observed in cells taken from the lesions. Immunoblotting demonstrated that proteins D and E were recognised by different classes of immunoglobulins in the sera of both patients as was flagellar antigen present in the outer-membrane preparation of the P. aeruginosa from patient 1. Iron-regulated membrane proteins (IRMPs) were similarly detected, but more strongly by IgM from patient 1. Furthermore, a marked antibody response to IRMPs was noted at the site of infection. Bands of a similar intensity were seen after absorption of the sera with lipopolysaccharide (LPS) purified from the infecting strain. This indicated that the response observed was directed against OMPs (including IRMPs) and not against contaminating LPS.

Antibodies, Bacterial↗

PubMed1988

The effects of antipsychotic drugs and symptomatology on perceptual asymmetry in schizophrenia.

Perceptual asymmetry was measured in acutely psychotic schizophrenic patients and normal controls using a dichotic monitoring task. Although the schizophrenic group differed from the controls in terms of accuracy and speed of response, there were no significant group differences with respect to asymmetries in these variables. The pattern of responding in the schizophrenic group was also examined in relation to differences in symptomatology and antipsychotic drug administration. These variables, in isolation and in interaction with each other, were found to have a number of effects on both asymmetry and overall level of responding. The results were interpreted in the context of an information processing model of functional hemisphere asymmetry in schizophrenia, and the implications regarding the nature of schizophrenic symptomatology and the effects of antipsychotic drugs were discussed.

Adolescent↗

PubMed1986

Hemispheric specialization and attention: effects of complete and partial callosal section and hemispherectomy on dichotic monitoring.

Dichotic word monitoring tasks were given to four cases with complete forebrain comissurotomy, three cases of partial section of the corpus callosum, one case of right hemispherectomy, and control subjects. The task involved a unimanual response to target words in either ear (divided attention, Experiment 1) or to target words in one voice that changed ears unpredictably (focused attention, Experiment 2). Left-ear extinction, defined as chance level (25%) detection of left-ear targets and 75% right-ear target detection, varied both between and within subjects during divided attention. No examples of extinction were obtained with focused attention. These results highlight attentional aspects of dichotic listening. Neither the structural, hemispheric asymmetry model (Cortex 3, 163-178, 1967), nor the cognitive, attention priming model (Attention and Performance V, pp. 87-97, Academic Press, New York) could account for the obtained results. We propose an alternative account in terms of the different processing modes and attentional capabilities of the two cerebral hemispheres.

Adolescent↗

PubMed1986

Schizophrenia: an information processing model.

There is a wealth of literature associating schizophrenia with disorders of information processing and attention. This paper draws together knowledge from experimental cognitive psychology and examines how both research findings and the clinical manifestations of schizophrenia can be accommodated by an information processing paradigm. An attentional model of schizophrenia is proposed in which disorders in the perception of information are related to dysfunction at the level of preattentive processes. This is seen as one crucial difference between schizophrenia and bipolar disorder, both of which demonstrate failures of sensory gating and filter mechanisms in the acquisition and processing of inputs. Commonalities between the two disorders are thus addressed. Certain psychopathological phenomena in schizophrenia, particularly negative symptoms ('inhibition'), hallucinations and delusions, are seen as compensatory operations of a disordered information processing system. The model has heuristic value and is able to account for, and coherently organise, the variability which continues to confound research in schizophrenia.

Arousal↗

PubMed1976