Circadian factors during sustained performance: Background and methodology

Cornell University Medical College, Westchester Division, The New York Hospital, White Plains, New York It is well established that there is a complex timekeeping mechanism in the human brain. This mechanism is associated with a variety of physiological and psychological rhythms having a period of about a day, and thus referred to as circadian rhythms. The circadian system has recently been modeled in terms of two underlying oscillators, one much more resistant to changes in routine than the other. These oscillators are considered to be endogenous, that is, internal to the organism, and not reliant for their existence upon changes in the person’s environment or general behavior. They thus continue to run even when the sleep/wake cycle is suspended, as in sustained operations. Thus, by their very nature, sustained operations require the individual to override the inputs that are coming from his or her circadian system (especially the indication that sleep is required). The aim of this paper is to provide a background to the area of circadian rhythms research, including a section on the methodology, so that the impact of the circadian system on sustained operations can be better understood.     

Tokens for stuttering

Four young stutterers were observed during 10 weekly sessions. Each session was divided into pretreatment, treatment, and posttreatment segments. Redeemable tokens were administered contingent upon stuttering behaviors in the treatment segment of the Experimental condition. In a Parallel Control condition, no tokens were administered during the entire session. The differences between the pretreatment and treatment segments were compared for the two conditions. Three subjects had dramatically fewer stuttering behaviors when tokens were being administered, while the fourth had more stuttering under the same condition. The subject whose stuttering increased had a history of therapy in which voluntary, “faked” stuttering had been called for, and the behaviors that increased were judged to be of this type. The decreases were interpreted as suggesting that the contingent tokens acted to countercondition the aversiveness of the stuttering experience, which reduced the anticipation of stuttering and hence the stuttering itself. The increase was felt to be simple reinforcement. The counterconditioning interpretation was borne out in two clinical applications in which money was presented contingent on stuttering behaviors judged to be aversive to the stutterer, and in which dramatically sudden, but long-lasting, improvement was seen.     

The relative effectiveness of alternative job sources

Vocational research has focused on the occupational choice process and the individual's adjustment to work. Very little research has examined the job search process in which the individual must engage in order to implement occupational choices. This study examines one dimension of the job search process: the relationship between job source and subsequent work experiences. The data reveal that when the respondents initially entered the labor market, those relying on formal job sources tended to work in higher-level occupations and in jobs more closely related to their training than their counterparts who used other job sources. In the longer run, the labor market advantages associated with the use of formal job sources dissipated for the engineering majors but tended to persist for the business alumni.     

New perspectives in temperament/personality research: The “Behavioral” model of the Warsaw group

This paper reviews the theory and research of the Warsaw school of differential psychophysiology, which has modified and extended the typologic model constructed by Teplov and Nebylitsyn. While Soviet theory still favors a relatively inflexible structure of nervous system properties as the biologic basis of individual differences in personality, Strelau and colleagues, in line with the action/activity model of Vygotsky and Tomaszewski, begin with the premise that for every individual there is a specific, genetically determined optimal level of arousal, a necessary background for fullest emotional and intellectual development. The person strives to create this optimal climate through an active process of stimulation control, achieved primarily through enhancement or dampening of reactivity—which describes innate responsivity in the reacting systems to both sensory and emotional stimuli—through various hormonal ‘tuning’ mechanisms and through “appropriate” activity, reflected in different cognitive styles and preference for certain work conditions. Such activities aim to ensure comfortable physical and psychologic environments, in which the individual can avoid conflict and stress. The system regulating and integrating such control mechanisms is the core of personality. Investigations of the Warsaw group on relationships between reactivity and different forms of stimulation seeking/control—risk-taking, work style preferences, cognitive style, defense mechanisms, for example—and between reactivity and tolerance of stress and conflict and their speculations about the neurophysiologic and endocrinologic mechanisms of stimulation control are described, as are a number of questionnaires developed by this group to measure reactivity, the temporal parameters of response, and stimulation-seeking in a variety of occupational and social contexts.     

Picture perception: An analysis of visual compensation

Although geometric information is altered when a picture’s viewing point is changed, such changes often do not affect perception. Two experiments assessed pictorial perception relative to the distortions introduced by viewing point dislocation. Results provide a psychophysical demonstration of pictorial compensation and suggest that it is based on the discrepancy between the actual and an assumed-correct viewing position. An explanation of pictorial compensation is offered that could be applied to direct picture perception and to picture-in-a-picture perception.     

Empirical sleep assessment in the home: A convenient,inexpensive approach

We have previously reported on a sleep assessment device (SAD) that addresses shortcomings inherent in self-report sleep data and polysomnography. The SAD produces a sleep record by tape recording subjects' verbal responses to auditory cues spaced at fixed intervals throughout the night. In prior studies, the SAD proved to be a reliable and valid assessment tool according to electroencephalographic comparisons. Herein, we report on the unassisted home use of the SAD by eight normal volunteers and four bedmates. Subjects and bedmates completed sleep questionnaires for 12 nights and subjects also employed the SAD the last 6 nights. Comparisons of subjects and bedmates self-report sleep data before and during SAD use indicated that the SAD did not disrupt sleep. Subjects were able to self-administer successfully the SAD in their homes. SAD data closely matched subjects' self-report data. The present study found the SAD to be an accurate, unobtrusive, and easily utilized empirical measure of sleep in the natural environment. In so doing, it extends the demonstrated reliability and validity of the SAD from the sleep laboratory to the home with normal sleepers.     

Development of clinical tests of vision: Initial data on two hyperacuity paradigms

Many basic psychophysical functions offer promise as clinical tests of vision. Here, we discuss problems that one encounters in the clinical setting, how one identifies a psychophysical test for potential clinical development, and an orderly approach to development of suitable test paradigms. Parameters are selected which are relatively insensitive to variables encountered in the field (clinic) in a normal population, but which are sensitive to changes in the response system being studied. Initial data on two hyperacuity tests are presented. These tests are adaptations of hyperacuity paradigms (Westheimer, 1979) to a clinical environment. This particular test set offers promise because it exhibits a unique threshold which is dependent upon neural data processing and is relatively independent of retinal image degradation.     

Interpersonal Reactions to Depression and Physical Disablllty In Dyadic Interactions1

Examined the interpersonal responses of persons engaged in dyadic interactions with confederates who enacted either depressed or socially appropriate roles and appeared either with or without a physical disability. Subject negative evaluations of confederates were indirectly obtained from a thought-listing measure. The overt behaviors of subjects were surreptitiously recorded on videotape and measures of verbal and nonverbal behavior were acquired. Subjects spoke less to the depressed targets and had significantly higher rates of negative evaluations of these persons. In addition, subjects gazed less at the depressed confederates. These effects were not moderated by target physical appearance. Findings are discussed as they relate to social models of depression and the stigmatizing effects of disability.     

Confidence depends on level of aggregation

The credible intervals that people set around their point estimates are typically too narrow (cf. Lichtenstein, Fischhoff, & Phillips, 1982). That is, a set of many such intervals does not contain the actual values of the criterion variables as often as it should given the probability assigned to this event for each estimate. The typical interpretation of such data is that people are overconfident about the accuracy of their judgments. This paper presents data from two studies showing the typical levels of overconfidence for individual estimates of unknown quantities. However, data from the same subjects on a different measure of confidence for the same items, their own global assessment for the set of multiple estimates as a whole, showed significantly lower levels of confidence and overconfidence than their average individual assessment for items in the set. It is argued that the event and global assessments of judgment quality are fundamentally different and are affected by unique psychological processes. Finally, we discuss the implications of a difference between confidence in single and multiple estimates for confidence research and theory.