The effect of gender and time-of-day on time perception and mental workload

Two experiments are reported which investigated how subject gender and time-of-day influenced the estimation of duration and the perception of task-related mental workload. In the first experiment, 24 subjects performed a filled time-estimation task in a constant blacked-out, noise-reduced environment at 0800h, 1200h, 1600h, and 2000h, respectively. In the second experiment, 12 different subjects performed an unfilled time estimation task in similar conditions at 0900h, 1400h, and 1900h. At the termination of all experimental sessions, participants completed the NASA Task Load Index workload assessment questionnaire as a measure of perceived mental workload. Results indicated that physiological response, reflected in body temperature change, followed an expected pattern of sequential increase with time-of-day. However, estimates of duration and the perception of mental workload showed no significant effects for time-of-day. In each of the experiments there were significant differences in time estimation and mental workload response contingent on the gender of the participant. These results are interpreted in light of the previous positive findings for circadian fluctuation in performance efficiency and the equivocal findings of a gender difference in time estimation. A unifying account of these collective results is given based on gender by time-of-day interactional effects. An earlier version of this paper was presented at the 32nd Annual Meeting of the Human Factors Society, Anaheim, CA, October, 1988.     

Relationship between religion-related factors and obsessive compulsive disorder

This exploratory study sought to determine whether selected religion-related factors differentiated between 86 patients with obsessive compulsive disorder (OCD), 73 patients with panic disorder, and 292 patients with other psychiatric (non-anxiety) disorders. A standard history questionnaire was used to obtain information from patients concerning religion of origin, involvement in religious activities, religious conflict, and perceived religiousness of parents. It was found that the percentage of patients who reported experiencing religious conflict was significantly higher for the OCD group than for the other two groups. Other findings suggested associations between Catholicism and OCD and between Protestantism and panic disorder, but further research is needed to clarify these relationships. This article is based on a paper presented at the 98th annual convention of the American Psychological Association, Boston, August 1990.     

Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

Memory deficits in Alzheimer's patients: A comprehensive review

Despite considerable experimental work on Alzheimer's disease (AD), the underlying cognitive mechanisms as well as the precise localization of neuropathological changes critical for memory loss remains undefined. A review of the neuropsychological literature on long-term memory deficits in AD patients suggests that AD patients display (a) a pervasive deficit of explicit memory, (b) a partial deficiency of implicit memory for verbal and visuoperceptual material (as measured by repetition priming procedures), and (c) a substantial sparing of implicit memory for visuomotor skills. The explicit memory loss is likely a result of encoding as well as consolidation difficulties. A faulty lexical-semantic knowledge structure appears responsible for deficient repetition priming effects. Since neuropathological changes diffusely affect the brain of AD patients, establishing a clear relationship between localization of cerebral lesions and memory deficits is particularly difficult. Nevertheless, data suggest that extensive involvement of the hippocampal-amygdala complex plays a major role in explicit memory loss. Damage to associative cortical areas likely is involved in repetition priming deficits. The relative integrity of primary motor and sensory cortical areas and of the basal ganglia likely subsume, by contrast, the normal learning of visuomotor skills.     

Computerized assessment in neuropsychology: A review of tests and test batteries

This article contains detailed reviews of 13 computerized neuropsychological and performance test batteries and six stand-alone computer tests. Tasks found on these instruments are described and tables illustrate which batteries employ which measures. In addition to issues of reliability and validity, special considerations apply to computerized assessment. These issues are discussed and readers are provided information to help them assess computerized tests in relation to their particular clinical and research needs. Since many computerized tests were developed as performance assessment tools, the relationship between performance and neuropsychological assessment is examined.     

Heart rate--QT relationships during baroreceptor stimulation with diminished autonomic influence on the ventricles. Ventricular autonomic tone and QT interval.

The shortening of the QT interval of the electrocardiogram coincident with acceleration of heart rate and vice versa has been accepted for many years as evidence that the action potential duration and hence QT are necessarily dependent on heart rate. Exceptions to this rule have been attributed to the intervention of counteracting autonomic effects. In order to test this assumption, 26 conscious dogs divided into three groups were tested during baroreceptor stimulation by a bolus injection of phenylephrine. Seventeen dogs had been used in earlier studies in which they had undergone an experimental anterior myocardial infarction with apparent full recovery. A group of those dogs underwent beta-adrenergic blockade by intravenous atenolol 30 min prior to the baroreceptor activation. To test the intactness of the baroreceptor responses in the previously infarcted dogs, a third group of nine dogs that had had no prior myocardial infarction was included. All dogs were adapted to the laboratory environment and were not sedated during experiments. Simultaneous recordings of RR, QT interval, and phasic arterial pressure were made in all dogs before and during baroreceptor stimulation. In the normal group, and the previously infarcted group that received no atenolol, baroreceptor stimulation elicited a small (8/msec), but significant prolongation of the QT associated with a nearly 50% reduction in heart rate. The QT interval of the atenolol-treated dogs, although significantly more prolonged before stimulation, remained unchanged during the reflex. The data indicate that withdrawal of ventricular sympathetic tone may prolong the QT interval, thereby confirming the role of sympathetic innervation in the control of QT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pavlov's position on the effects of decortication on conditional reflexes.

This paper examined D. Joravsky's (1989) hypothesis that I.P. Pavlov dogmatically refused to acknowledge that classical conditioning can be mediated by subcortical regions of the large cerebral hemispheres. Decortication literature from 1901 to 1936 was reviewed. The early studies available to Pavlov, who died in 1936, showed that decortication does not allow the establishment of new or retaining of old conditional reflexes (CRs). G.P. Zeleny?'s later experiments(1930) suggested that the establishment of primitive CRs in decorticated dogs was possible. Pavlov never denied this possibility but cautioned that Zeleny?'s experiments could have been methodologically flawed. Although Joravsky's original hypothesis on Pavlov's position on the relation between decortication and the establishment of CRs is by and large accepted, it must be stressed that Pavlov's theory of higher nervous activity was primarily concerned with the function of the brain in the higher organism's struggle for existence. Within this context the cortical, rather than subcortical, processes play the decisive role in the organism's adaptation to the changing external environment.