Effects of task instructions and oscillation frequency on bimanual coordination

Increases in the oscillation frequency of bimanual movements produce a switch from an anti-phase (180° relative phase) to an in-phase (0° relative phase) coordination pattern. This finding is observed when subjects are instructed not to intervene when they feel themselves slipping out of the anti-phase pattern. The question addressed in this study concerned how performance would be affected if subjects were instructed to try to maintain the pattern at all times. This issue was addressed using two separate groups of subjects: one group was given the do not intervene instructions, the other group was told to try to stay with the pattern at all times. Forearm rotations were tested in 15 s trials, paced by an auditory metronome set at 1.0, 1.5, 2.0, 2.5, and 3.0 Hz. Frequency distributions of the point estimates of relative phase were analyzed. The Do not Intervene group replicated previous findings, as indicated by the development of a bimodal histogram of relative phase distributions with increases in oscillation frequency. However, a very different pattern of findings emerged with increases in oscillation frequency for the group told to stay with the anti-phase pattern. Rather than a bimodal distribution being developed, the data maintained 180° as its central tendency — no secondary distribution developed around 0° relative phase. These data suggest that volitional control can over-ride the inherent dynamical tendencies of the motor system.     

Effects of diagnostic classification systems on clinical hypothesis-generation

In this study it was determined whether (a) classification as opposed to absence of classification has an effect on the quality of clinical hypotheses (b) the DSM-III-R and the CBCL have a different effect on the quality of clinical hypotheses, and (c) the potential difference between the DSM-III-R and the CBCL is moderated by the different number of syndromes identified by these systems. To investigate these questions, an experiment was conducted in which 86 clinicians generated hypotheses for six cases. The clinicians were divided into a DSM-III-R, a CBCL, and a control group. Of the six cases, two were classified by both classification systems as one syndrome, two were classified as one syndrome by the DSM-III-R but as two syndromes by the CBCL, and two were classified as two syndromes by the DSM-III-R but as one syndrome by the CBCL. The quality of the hypotheses was determined by means of four dependent variables selected from an overview of qualitative criteria: explanatory value, redundancy, possibility of operationalization, and specificity. No differences between the CBCL and the control groups were found. The DSM group performed better than the control group regarding explanatory value and redundancy. The DSM-III-R group also scored better than the CBCL group regarding explanatory value, particularly when the number of identified syndromes was two for the CBCL and one for the DSM-III-R.     

Teaching peer reinforcement and grocery words: An investigation of observational learning and instructive feedback

A multiple probe across behaviors design, replicated across participants, assessed the effectiveness of constant time delay in teaching appropriate peer reinforcement and grocery words to 3 elementary students with moderate intellectual disabilities. Additionally, pretests and posttests assessed the acquisition of the participants' observational learning (acquisition of peers' grocery words) and instructive feedback (related information supplied by the teacher in the consequent event). Results indicate that the participants learned (a) how to appropriately reinforce peers, (b) to read their grocery words, (c) some of the targeted stimuli of their peers, and (d) much of the instructive feedback that was associated with each of the grocery words. Maintenance data indicate that the participants maintained their target grocery words at high levels of accuracy.     

An injection olfactometer for humans and a new method for the measurement of the shape of the olfactory pulse

An injection olfactometer for human psychophysical experiments is described. The olfactometer is capable of presenting, either mono- or birhinally, single odorants and binary mixtures. The pulse form of the olfactory stimulus at the exit of the olfactometer approaches a rectangular form, which makes the olfactometer well suited for olfactory reaction time measurements. Since stimulation periods are independent of the subject’s inhalation, time-intensity measurements over prolonged periods of time are possible as well. In the second part of this paper, a new technique is described for the measurement of the stimulus pulse form at the exit of the olfactometer.     

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.     

Field dependence and the effect of REM deprivation on thirst.

Recently a number of studies have concerned the possible function of rapid eye movement (REM) sleep and the mastery of stress. The present study was designed to explore the possibility that REM sleep might play a function in reducing the potency of a stressful physiological stimulus, thirst, as well as the possibility that such a function might be specific to individuals falling at different points along the field-dependence dimension. While there was no difference between REM deprivation and non-REM awakening nights in subsequent morning thirst, there was a significant interaction between field dependence and night on morning thirst measures for 10 college students. These results are discussed in light of previous work on stylistic differences in dreaming and their possible role in adaptation to stress.     

The integration of motivational information: A conjoint measurement analysis

Within Anderson's (1974a, b, c, 1978b) information integration theory, the integration of motivational information was investigated by means of conjoint measurement techniques. Eighteen university students were asked to judge hypothetical co-students characterized by three features (intelligence, motivation and the extent to which they study) according to their chances to pass. Both rank order data and ratings were obtained. The orderings of most subjects could be represented very well by an additive model. A polynomial regression procedure was applied to determine the shape of the response function for the ratings. As this function was quite linear for all subjects, the ratings could be said to form an interval scale.     

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.