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Biomedical subjects

R W Neufeld

Publications and source records attributed to R W Neufeld.

At least 37 records · Page 2Linked to original sources
PubMed1987

Span of apprehension among remitted schizophrenics using small visual angles.

Evidence concerning span of apprehension (SOA) performance as a potential marker of vulnerability to schizophrenia has been the subject of several recent investigations. There is agreement that earlier findings of performance deficits among offspring of schizophrenics and among schizophrenics in remission may not extend to more foveal, as opposed to peripheral, presentations of visual arrays of the SOA task. Using the former format of presentation, the current study found that performance of episodic patients was distinguishable from that of nonpatient controls but performance of remitted patients was not. Readings of psychophysiological activity (heart rate) obtained during SOA task performance were higher among episodic patients than among others, suggesting that such measures may be promising markers of episodes of schizophrenia.

Adolescent↗
PubMed1987

Attentional resources and hemispheric functional asymmetry in schizophrenia.

Inconsistent findings within certain areas of schizophrenia research--processing of verbal and pictorial stimuli, and hemispheric functional asymmetry--suggest the importance of examining the attentional resources associated with the cerebral hemispheres among schizophrenics. A cognitive task battery was developed which assessed the functioning of the left and right hemispheres under varying attentional loads. This battery was administered to paranoid and non-paranoid schizophrenics, and three control groups. Error rate and response latencies were monitored. It was found that the schizophrenics, particularly the non-paranoids, displayed evidence of a generalized decrease in available resources across attentional pools. In addition, response latencies were indicative of a complex interaction involving loads and visual field of stimulus presentation, which differed across schizophrenic subtypes. These lateralized effects among the schizophrenics did not interact with the differential sensitivity of the hemispheres to stimulus characteristics.

Adolescent↗
PubMed1986

The interactional model of anxiety: an evaluation of the differential hypothesis.

The interactional model of anxiety states that individuals who score high on trait anxiety measure for a specific situation dimension will respond with elevated state anxiety only in reaction to encounters with congruent situations. We tested this model by presenting subjects who scored high or low on ego threat, physical danger, novelty ambiguity, and daily routine trait measures with stressors representative of the four situation dimensions. The interactional model was partially supported for ego threat trait anxiety. However, results generally supported the influence of situation rather than the trait or interaction on anxiety response. The lack of trait factor independence for the novelty ambiguity and daily routine trait dimensions is discussed as a potential reason for the nonsupport of the interactional model. Finally, we suggest that the experimental design used in this study is a more accurate and vigorous test of the differential hypothesis than past research.

Adaptation, Psychological↗
PubMed1985

Heart beat interoception: a study of individual differences.

There were two principal aims of the study: to carry out preliminary evaluation of a novel heartbeat tracking technique for objectively measuring cardiac interoception; and to determine whether good and poor heartbeat perceivers could be differentiated with respect to other parameters reflecting individual differences in emotionality, including gender and 'emotional character'. Subjects first completed a battery of self-report questionnaires designed to measure characteristics of emotional experience, and then underwent a series of heartbeat tracking trials in which they used the index finger to tap in synchrony with their ongoing heartbeat activity (interoceptive tracking) and also with an audiotape of pre-recorded heartbeat sounds (exteroceptive tracking). The perceptual index was based on the variability of beat to tap latency. Concurrent validity findings suggested that the tracking index reflects a promising measure of cardiac interoceptive acuity. Good perceivers were found to have higher heart-rate measures than poor perceivers. With regard to 'emotional character' good perceivers had higher state anxiety, and were less emotionally expressive, although these differences were only marginally significant (P less than 0.08) with multivariate testing. Applications of the heartbeat tracking technique for further empirical evaluation of the role of interoception in emotion are discussed.

Adolescent↗
PubMed1985

Cognition and symptomatology in schizophrenia.

The experimental work on cognitive processes in schizophrenia is critically reviewed with respect to its relevance in understanding schizophrenic symptomatology. Several logical and empirical issues that complicate any comprehensive attempt to relate schizophrenic symptoms and information processing are discussed. Studies germane to schizophrenic sensory/perceptual, cognitive, affective, and motor anomalies are examined, and it is concluded that the cognitive approach to these areas is promising, but further research and theory elaboration will be required in order to provide a firm basis for cognitively oriented intervention attempts.

Affect↗
PubMed1984

Imagery and verbal aspects of schizophrenic informational performance.

Imagery and verbal aspects of schizophrenic informational performance were examined. Pictorially and verbally presented pairs of items were compared with respect to both pronounceability of their names and their real-life sizes. Results indicated slower stimulus encoding of pictorial than verbal stimulation among the schizophrenics, especially paranoids. On the other hand, comparison of item properties appeared intact regardless of stimulus-presentation format. Non-paranoids made fewer errors as size judgements became more difficult, suggesting protection against erroneously stating the presence of stimulus properties. Scores from a questionnaire directed toward habitual use of imagery and verbal processes indicated significantly greater preference for the latter among paranoids.

Adult↗
PubMed1982

Paranoid-nonparanoid schizophrenic distinctions in implementing external conceptual constraints.

Using procedures originated by Bruner et al. (Bruner, J. S., Goodnow, J. J., and Austin, G. A Study of Thinking. John Wiley & Sons, New York, 1956), paranoid and nonparanoid schizophrenics and nonpatients were compared on performance in identifying rules for organizing multidimensional items. Successive item selections were accompanied by feedback as to whether or not each corresponded to the rule currently in effect (either conjunctive, inclusive-disjunctive, or biconditional). The most pronounced aspects of deficit associated with paranoid status were related to performance latency. Examination of results in the light of component operations underlying the present task indicated that paranoids' lower performance stemmed from difficulties in initially translating stimulus properties into a task-facilitative format. Findings were related to earlier paranoid distinctives in (choice) reaction time latencies, as well as to earlier findings on rule definition learning involving procedures closely related to the present ones. As well, inferences were drawn as to conditions of rule acquisition where differential latency aspects of performance are likely to be most pronounced among paranoids.

Adolescent↗
PubMed1981

Sources of differential stress response associated with psychometrically designated anxiety proneness.

This research examined different aspects of the expression of psychometrically designated anxiety proneness related to dimensions of "ego threat" and "novelty ambiguity." In an ego-threatening situation, subjects were presented with abstract-reasoning items whose stress-relevant properties-item difficulty-had earlier been scaled among comparable samples. In the first study, comparisons focused on objective outcomes (records of task failure) as well as appraised outcome records and appraised task effort necessary for adequate performance. In the second study, comparisons emphasized direct physiological and subjective reactions to the stressing situational properties. Results indicate that anxiety proneness is associated with variation in direct reactions to the stressing properties but not with variation in the configuration of the objective or appraised properties themselves. Implications for current concepts on the expression of anxiety proneness and for its psychometric prediction are discussed, as are certain similarities between the present findings and those from research on other sources of individual differences in stress response. Differential sensitivities of alternative indices of stress reaction to variation in anxiety proneness are considered in the light of earlier studies.

Achievement↗
PubMed1981

Evaluation of information sequential aspects of schizophrenic performance. I. Framework and current findings.

Based on studies of normal cognition, a schema of sequential stage information transactions is used to organize and evaluate relevant findings on schizophrenic performance. Principal stages include precategorical processing, short term or working memory, and long term memory. Difficulties associated with both structural aspects and information extraction aspects of precategorical processing are presented. Assessment of short term and long term memory performance agreed with earlier observations of certain "strengths" but with elaboration as to specific points where changes in requirements appear to have perturbing effects. Throughout the text, a number of outstanding research questions are noted and described.

Cognition↗
PubMed1981

Evaluation of information sequential aspects of schizophrenic performance. II. Research strategies and methodological issues.

This presentation deals with research issues surrounding the investigation of schizophrenic performance from the perspective of the experimental psychology of normal cognition. Topics of subject selection, influence of medication on subjects' performance, appropriateness of underlying models of performance developed with normal samples, and nonuniform measurement properties of dependent variables are dealt with. Relevant items of rationale for this branch of study are put forth and evaluated. Finally, the notion of critical deficit--whereby the importance of deterioration in a component of performance is judged according to the component's role in negotiating environmental demands (rather than the component's absolute magnitude of deterioration)--is detailed and exemplified.

Cognition↗