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.     

Interpersonal Features of Interviews Between Psychiatric Patients and Nursing Staff1

Observer ratings of one-half hour interviews were undertaken to test two basic concepts of interpersonal relations in a sample of 51 randomly paired male psychiatric patients and female psychiatric nurses. It was hypothesized that the behavior of psychiatric patients could be organized around two orthogonal dimensions reflecting status and feeling, and that patients and nurses would exhibit complementary interpersonal behavior consistent with their institutionally ascribed roles. Interviews were rated with the Leary Interpersonal Checklist. Interjudge reliability was established for Leary's coding system. The hypothesis of status and feeling reference points for patient behavior received strong support when the results of analysis of variance were supplemented by factor analysis. Patient scores on the eight variables measured by the Leary Interperonsal Checklist and nurses' scores for 17 complementary variables were submitted to correlational analysis to test the hypothesis of interpersonal complementarity. As predicted, two hypothesized dependence-assistance response combinations provided the highest correlation coefficients. It was concluded that the study provided empirical support for the utility of an interpersonal model within psychiatric settings that has more commonly been identified with relationships free of psychiatric disturbance.     

CULTURAL VARIATION IN PROBABILISTIC THINKING: ALTERNATIVE WAYS OF DEALING WITH UNCERTAINTY*

This study reviews research on cultural differences in “probabilistic thinking” and presents some intra- and inter-cultural findings. Strong differences are shown to exist between people raised under Asian and British cultures on measures of this ability. These differences were found to out-weigh any influence of subculture, religion, occupation, arts/science orientation and sex. Generally, Asians were found to adopt a less finely differentiated view of uncertainty both numerically and verbally than did the British sample. Numerical probabilities assessed by the Asians were more extreme and less realistic than those assessed by the British sample. Possible antecedents of these differences are outlined, and cultural differences in probabilistic thinking are shown to be compatible with decriptions of cultural differences in business decision making. It is argued that there are qualitative cultural differences in ways of dealing with uncertainty.     

A repertory grid study of therapist/couple interaction

A case of marital therapy is described in which the presenting problem, one of non-consummation, is treated by the standard Masters and Johnson's technique. Using repertory grids at the start and finish of treatment the changing perceptions of both partners and the therapist were determined. In spite of an ostensibly behavioural treatment, substantial changes occurred in the couple's understanding of the nature of their problem. The changes undergone in the couple's perceptions, and their differences from the therapist's assessments of change give rise to speculations about the nature of the therapeutic interaction and suggest further lines of exploration.     

Robust estimation of ability in the Rasch model

Estimating ability parameters in latent trait models in general, and in the Rasch model in particular is almost always hampered by noise in the data. This noise can be caused by guessing, inattention to easy questions, and other factors which are unrelated to ability. In this study several alternative formulations which attempt to deal with these problems without a reparameterization are tested through a Monte Carlo simulation. It was found that although no one of the tested schemes is uniformly superior to all others, a modified jackknife stood out as the best one in general, it was also super efficient (more efficient than the asymptotically optimal estimator) for tests with forty or fewer items. It is proposed that this sort of jackknifing scheme for estimating ability be considered for practical work.This research was funded through a grant from the Law Enforcement Assistance Administration (78-NI-AX-0047) to the Bureau of Social Science Research, Howard Wainer, Principal Investigator. We would like to thank Ronald Mead, Anne Morgan and James Ramsay for kind, generous, and invaluable help at various stages of the project.     

Will both spouses have careers?: Predictors of preferred traditional or egalitarian marriages among university students

This study examined the significance of work preference variables, family preference variables, socialization influences, and needs for achievement and affiliation in predicting preferred traditional versus egalitarian marriages among university students. Results showed that, overall, male university students preferred traditional marriages while female university students preferred egalitarian marriages. Sex also interacted significantly with the following variables: desired family task involvement, desired job task involvement, and mother's family involvement. The data suggest that a perspective encompassing a wide variety of variables (including work, family, and socialization considerations) may be useful for conceptualizing individuals' preferences for traditional or egalitarian marriages. Implications of the results for management and career counseling are discussed.     

The effects of binocular and motion-generated information on the perception of depth and height

The perception of distance and size in the presence of optical gradient information was investigated under four viewing conditions—binocular view with and without head motion, and monocular view with and without head motion. Subjects (60 adults) matched distance intervals (from 15 to 127 cm) and heights of a target triangle (from 5 to 15 cm) by adjusting the length of a metal tape. Both linear and power functions were fitted to each individual’s distance judgments, and the competing perceptual models were compared. For both models, it was found that binocular information was sufficient to specify relative, but not absolute, distance, that monocular information was sufficient to specify an orderly relation between target distance and judgment but not absolute distance, that average error was less in the binocular conditions, and that perceived distance was not affected in either condition by the addition of head motion. The analysis of size judgments revealed that monocular and binocular judgments did not differ, that matches made with and without head motion did not differ, and that, in all conditions, matches exceeded target heights by an average 30% to 40%. Judged size was also analyzed as a function of target distance. In all conditions but monocular view with head motion, the effect of distance was to increase size judgments. The distance judgments support the hypothesis (Purdy, 1958) that the binocular stimulus carries information that the monocular stimulus does not; they fail to support the hypothesis (Gibson, 1966) that observer motion adds information to the static stimulus. The size judgments support neither hypothesis but suggest an independence of perceived size from perceived distance.     

The development of automatic word recognition and reading skill

The development of automatic word recognition as a function of reading skill was investigated in three experiments using the Stroop task. Reading skill level ranged from nonreaders to readers above the sixth-grade equivalent. Interference with color naming begins to emerge early in the process of learning to read, increases, and then subsequently decreases. Strings of identical letters delayed color naming for children just beginning to learn to read. The interference from words, presumably reflecting semantic processing, began developing early but did not peak until the second- to fourth-grade reading levels. These different sequences of development of interference in the various stimulus conditions suggest that word recognition is the result of a number of component processes that develop as children acquire skill in reading.     

Does reward depletion influence spatial memory performance?

If spatial memory tasks are considered as foraging problems, it can be predicted that rats' difficulty in learning a win-stay task—revisiting part of a maze where food has recently been found—should be partly overcome if the food is not fully consumed at the first visit (nondepleted reward) rather than being all eaten (depleted reward). Three experiments confirmed and further analysed this result. Experiments 1 and 2 showed that it does not depend on the amount of food initially found; nor is win-stay performance affected by the amount of food actually eaten. Experiment 3 suggested that the effects of nondepleted reward are mainly due to the animals' being interrupted while eating, and very little to the fact that uneaten food is left behind. The results are discussed with regard to their implications for learning theory, and for the application of foraging theory to learning and memory experiments.