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Biomedical subjects

R W Neufeld

Publications and source records attributed to R W Neufeld.

51 records · Page 3Linked to original sources
PubMed1978

The nature of deficit among paranoid and nonparanoid schizophrenics in the interpretation of sentences: an information processing approach.

Compared paranoid and nonparanoid schizophrenics to normal controls on a sentence verification task. The task permitted separation of times taken for central scanning and comparison operations and for operations associated with response selection and response execution. Neither group of schizophrenics took more time than normal controls for the latter operations; however, both groups of schizophrenics took longer at central scanning and comparison. Performance on this task was compared to previous results in which schizophrenics were similar to normals on times for central scanning and comparison, but took longer for non-central aspects of processing. It was condluded that the present deficit at the central processing level was attributable to deficient short-term memory of the encoded version of the sentence during the scanning and comparison operations. The absence of differences in the time taken for the non-central operations was ascribed to the exclusion of sentence encoding from the present latency times.

Adult↗
PubMed1978

Veridicality of cognitive mapping of stressor effects: sex differences.

In order to examine the veracity of judgment-questionnaire data regarding the effects of confronting a stressor in various contexts, judgments based on the imagined consequences of these encounters were scaled for both male and female subjects using individual-differences multidimensional scaling analyses. A parallel experiment was then carried out where a second group of subjects were directly exposed to the spectrum of stressor-context combinations previously judged. The two experiments substantially differed with respect to the inferences suggested by their results: while there were no apparent sex differences in the configuration of judgment responses, there were appreciable sex differences in response to the direct stress; other effects were predicted according to the judgment-scaling results but were not obtained upon direct stressor exposure. The study extended past results of equivocal veracity of conclusions drawn from personality questionnaires, ratings and inventories to the domain of stress reactions. The role of antecedent cognitive structuring of threatening situations along stress-relevant dimensions in determining response to direct threat was discussed. Discussion also focused on the configuration of sex differences over the several measures of response to the direct stressor. It was suggested that the stressor was more potent for females leading to increased cognitive coping efforts on their part. The effect of these efforts was the eventual reduction of their subjective stress to the level of that displayed by males.

Adaptation, Psychological↗
PubMed1977

Effect of stimulus context and repeated aversive visual stimulation on the cardiac correlate of attention.

The experiment investigated cardiac deceleration responses to repeated presentations of an aversive visual stimulus (a slide of a mutilated homicide victim) as a function of interspersing presentations of different types of other provocative visual stimuli amidst the aversive stimulus. 30 male volunteers were divided into three groups of 10 subjects each. One group viewed the aversive stimulus randomly interspersed with presentations of female nudes (positive context); a second group viewed the aversive stimulus amidst presentations of slides of skin-disease patients (negative context); and the third group viewed the aversive slide surrounded by presentations of other male undergraduates (neutral context). After repeatedly viewing the single homocide-victim slide, subjects viewed five different homicide scenes without contextual slides. These identical procedures were repeated during a second experimental session. A significant context-by-sessions interaction (p less than .05) reflected a decrement in cardiac deceleration over sessions for the positive context and an increase in deceleration from the first to the second session for the negative context. The neutral context did not affect cardiac deceleration over sessions. The series of different homicide scenes elicited greater cardiac deceleration than repeated exposures to the same slide. These results were discussed in terms of the possible role of stimulus context in affecting attention and vigilant-avoidant coping orientations.

Adolescent↗
PubMed1977

Response-selection processes in paranoid and nonparanoid schizophrenia.

Previous research (Marshall, 1973) has shown that the most pronounced component of deficit on a choice reaction time task among a mixed schizophrenic sample involved response-selection processes. Other evidence has indicated that paranoids may be more deficient in this respect than nonparanoids. Hence, it was hypothesized that the former subgroup of schizophrenics would display response-selection deficit while the latter subgroup would display either less or no deficit. Response-selection processes were re-examined using the CRT paradigm with comparisons carried out among paranoid and nonparanoid schizophrenics and a group of nonschizophrenic controls. Results indicated that only the paranoid schizophrenics displayed abnormally retarded response-selection operations, the nonparanoid schizophrenics being nonsignificantly discriminable from the controls. It was suggested that past evidence of CRT response-selection deficit among mixed schizophrenics might have been attributable primarily to the performance of the paranoids, whose performance appears to be adversely affected by an increase in the number of dimensions relevant to response selection.

Association↗
PubMed1976

Evidence of stress as a function of experimentally altered appraisal of stimulus aversiveness and coping adequacy.

The present study examined the effects of initial appraisal of stimulus aversiveness and coping adequacy on subsequent evidence of stress. Results indicated that level of appraised coping efficacy had the most pronounced effect during stressor exposure and that the pattern of this effect was dependent on whether the source of the appraised coping resources was "personal" (the subject's own resources) or "environmental" (a bogus technique donated by the experimenter). In addition, information about personal resources reduced the pre- to poststressor increment in state anxiety and lessened cognitive avoidance of stressor-related stimuli. Results were discussed with respect to differential sensitivity of components of stress response to variation in environmental versus personal sources of coping efficacy, and the specific aspects of cognitive structuring associated with variation in physiological reaction (muscle tension) were noted. The importance of factors associated with appraised coping efficacy was clearly supported, but factors involving the objective (in contrast to defensive) aspects of appraised stressor potency required further investigation, and suggestions for such future research were made.

Anxiety↗
PubMed1976

Relationship between conceptual judgements and stimulus dimensions among schizophrenics and normals.

Eighteen paranoid schizophrenics, 18 non-paranoid schizophrenics and 18 normal subjects were shown a set of 36 schematic drawings of human faces. The faces varied along four dimensions: nose length, chin length, distance between eyes, and forehead height. Subjects were asked to rate each face as either 'intelligent' or 'unintelligent' and then as either 'contented' or 'discontented'. The paranoid schizophrenics were less systematic than both the normals and non-paranoid schizophrenics in their use of the stimulus dimensions in the judgements, the latter two groups not significantly differing in this respect. It was also found that there were significant differences among the groups regarding the average importance given to the different physical features, the profiles for the two schizophrenic groups being flatter than that of the non-schizophrenics. The results suggested there were two aspects of consistency in dimension utilization involved in the overall group differences-between-subject and within-subject consistency. The paranoid schizophrenics displayed low within-subject consistency, the non-paranoid schizophrenics displayed a high within-subject consistency but low between-subject consistency (i.e. an idiosyncratic weighting of dimensions in their judgements), and the non-schizophrenics displayed high within- and between-subject consistency.

Adult↗
PubMed1975

Effect of cognitive appraisal on d' and response bias to experimental stress.

The effects of an intellectualization-denial passage designed to modify cognitive appraisal of stressor stimuli (gory scences) were evaluated in terms of sensory-decision theory analysis. The passage was found to reduce "felt stress" ') for certain pairs of the stimuli addressed by the passage content but to less effective in reducing stress (Lx) was reduced rather than increased wi;h presentation of the passage for the included simuli only. Differences in d' between subjects classified within treatment groups as repressors versus sensitizers were obtained for certain stimulus pairs generally in the direction of lower sensitivity for repressors. Results are discussed in terms of the effects of altered cognitive appraisal on the "prevention of stress" and on "defensive"denial.

Arousal↗