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.     

Experimental evidence for the similarity of personality and attitude item responding

The process of responding to attitude items was broken down into a series of cognitive stages and a model offered. To test this model, subjects responded to attitude items varying in Extremity under two or five response alternative formats. By measuring response times, and applying Sternberg's (1969) additive factor method, the model was supported. The results were discussed in terms of previous process work involving personality items and sentence verification tasks.     

The effects of memory load and the contrast of the rod signal on partial report superiority in a Sperling task

Subjects participated in a Sperling task. The independent variables included delay of report cue, dark background field vs. a light background field intense enough to nearly saturate the rod system (duration of rod icon), and whether or not subjects were required to retain a list of letters or words (memory load) while performing in the Sperling task. Partial report superiority is normally taken as an indication of iconic memory. However, the main result was that memory load, which presumably does not affect the duration of the icon, increased partial report superiority. The effect of luminance of the background field was to reduce the partial report superiority. The results show that the existence of a partial report superiority and/or a decaying partial report curve does not necessarily imply the existence of an icon or visual storage.     

The children of Mexican-American migrant workers: A population at risk?

The present study assessed intellectual, academic, and emotional strengths and weaknesses for a group of Mexican-American children of migrant farm workers. In order to test the vulnerability hypothesis, the test profiles of these children were contrasted with those of two groups of black children with similar demographic makeup. The children of one group (Clinical Black) had been referred previously for a psychological consultation while the children of the other (Nonreferred Black) had not. Across dependent measures, between-groups contrasts tended to describe the scores of the Migrant children as similar to those of the Clinical Black children and significantly below those of the Nonreferred Black children. The findings suggested specific intellectual, academic, and emotional vulnerabilities of the Migrant children and demonstrated the need to develop ameliorative programs for these children.The authors wish to thank the staff of C & Y, University of Virginia Hospital, especially Ms. Deborah Johnson and Ms. Suzanne Canale, whose cooperation and assistance made this project possible.     

Decoding effects of cognitive complexity,tolerance of ambiguity,and verbal–nonverbal inconsistency1

The effects of inconsistency between the verbal and nonverbal components of a message were investigated. Subjects were 72 females who rated the attitudes of encoding confederates who communicated either consistent or inconsistent messages. Verbal and nonverbal components were varied as either positive or negative and each of the four possible combinations served as an experimental condition. The nonverbal cues of amount of eye contact, postural orientation, forward–backward lean, and head nodding were found to influence the judgment of the total message. Verbal and nonverbal components were found to have interactive rather than additive effects. Inconsistent nonverbal cues had a stronger effect when accompanying a positive verbal message than when accompanying a negative verbal component. The effects of decoders' levels of cognitive complexity and tolerance of ambiguity were also assessed. Evidence suggests that both complexity and ambiguity tolerance have effects on the utilization of inconsistent nonverbal cues. Low complexity/low tolerance subjects were less influenced by nonverbal cues in the positive verbal–negative nonverbal condition. These subjects were also found to differentiate less between supplied rating dimensions than other groups.     

REM motivation induced by brief REM deprivation: the influence of cognition, gender, and personality.

Prominence of the brain's right-hemisphere information processing and intensity of dream experience are two theoretically related constructs that have been proposed as important psychological aspects of REM sleep. Either view is consistent with the prediction that the effect of REM deprivation will depend in part on the nature of cognitive activity that is initiated at the onset of each REM period and that "substitutes" for the interrupted REM process. In the present study, the effect of REM deprivation was more striking for female subjects given a digits task than for female subjects given a fantasy-reporting task during awakening used to induce REM deprivation for the first 6 hours of the night. High neuroticism appeared to exaggerate the effect. No corresponding pattern was observed for the male subjects. These preliminary finding may be exaggerated by cognitive activity that is functionally incongruent with those processes. The results also raise interesting questions about individual differences.     

Masculinity and femininity as factors in feminism

The relationship between feminism and sex roles was explored in two studies. In female college students, sex-role types were measured by Baucom's (1976) MSC and FMN scales and by Bem's Sex-Role Inventory (Bem, 1974). Feminism was measured by the Attitude Toward Women Scale (AWS, Short Form) (Spence & Helmreich, 1972) and the Women's Liberation Scale (WLS) (Goldberg, 1976). Two groups of women were predicted to be more profeminist than others. (a) those scoring high on both masculinity and femininity and (b) those scoring high on masculinity and low on femininity. Results of the study supported both hypotheses using the AWS but not the WLS. In the second study, MSC and FMN served as the basis for forming sex-role types, and feminism was measured by participation in NOW. Again, a large number of women high on masculinity and low on femininity were feminists: however, women high on both masculinity and femininity were underrepresented in NOW. Different results in the two studies are discussed in terms of the different ways that feminism was measured.     

A form of behaviour therapy for some states diagnosed as “affective disorder”

Certain of the states commonly diagnosed by psychiatrists as “affective disorder” do not respond favourably to the usual treatments prescribed, and it is argued by Lum (1976) that such states are not appropriately labelled, as they are primarily due to the somatic condition of hypocapnoea—an abnormally low level of arterial carbon dioxide. This condition is well-recognized and can be diagnosed by appropriate physiological investigation. Hypocapnoea seriously affects various somatic systems, and if the patient later experiences affective distress it is a secondary symptom due to a vicious circle mediated by autonomic responses. The treatment of choice is a form of behaviour therapy aimed at altering the breathing response in the direction of building up toleration of a higher habitual level of arterial carbon dioxide. Existing work by behaviour therapists and others on the physiological and behavioural responses to varying levels of arterial carbon dioxide is cited, and the rationale of symptomatic treatment is discussed. Current treatment methods for hypocapnoea, although behaviourally oriented, are not closely in accord with the principles of modern behaviour therapy, and this paper suggests some directions of improvement.