The internal clock: evidence for a temporal oscillator underlying time perception with some estimates of its characteristic frequency

Evidence for the proposition that human time perception is determined by an internal clock is largely indirect. It would strengthen the case for this hypothesis if a model for the internal clock were available from which predictions could be derived and tested, and if the basic parameter of such a model, the frequency at which the clock runs, could be estimated. A model for an internal temporal pacemaker is briefly described and its properties are explored by computer simulation. Results are obtained that provide a basis for predicting that, under appropriate conditions, interference between an imposed rhythm and the frequency of a temporal oscillator may cause perturbations in temporal judgment which are related to the characteristic frequency of that oscillator. Experimental data are reported which appear to demonstrate such an interference pattern. These results allow some estimates of the characteristic frequency of the temporal oscillator to be obtained.     

Interpersonal loss and self-mutilation

Self-mutilation was hypothesized to increase in frequency during periods of interpersonal loss in a treatment program for seriously disturbed adolescents. The study examined changes in the frequency of acts of self-mutilation, aggression, and running away for 32 teenagers who experienced interpersonal loss when staff members left employment. Data were collected for a 4-year period. Statistical findings indicated that the frequency of self-mutilation increased significantly during the time period of anticipated loss, 2 weeks prior to staff terminations. There was no significant increase in the frequency of self-mutilation immediately following the staff terminations. Also, there was no significant change in the rates of aggression or running away either before or after the loss events. It was concluded that the time of anticipated loss was the period of highest risk for these adolescents in terms of self-mutilative behavior.     

Disordered eating in women of color

It has been assumed that the occurrence of eating disorders in American racial minority groups are rare. Indeed, whereas the cultural context may afford “protection” to the group, it does not necessarily protect specific individuals. Individuals within each racial/ethnic group are subject to the standards of the dominant culture, particularly when the culture-of-origin is devalued by the dominant culture. Social, familial, and individual factors which contribute to disorders eating symptomatology are discussed. Discussions of obstacles to detecting eating disorders and guidelines for developing more inclusive theory of and treatment of persons with eating disorders is included.     

Light-dark variation and changes across the lactational period in the behaviors of undisturbed mother and infant guinea pigs (Cavia porcellus)

Lactating guinea pigs (Cavia porcellus) and their litters were observed by videophotography across the light/dark cycle at 1, 11, 21, and 31 days postpartum. The highest level of behavioral activity was seen in the dark, particularly in the hour after light offset. This circadian pattern was evident from Day 1 in mothers and from Day 11 in pups. Contact between mothers and pups was inversely related to activity, occurring more frequently during light. Maternal grooming of pups occurred on Day 1 and then declined: self-grooming by pups increased across days. Intake of solid food and water by pups occurred on Day 1 and increased thereafter. A nearly complete transition from nursing to independent ingestion was observed between 21-31 days of age. Overall, we document several ontogenetic changes in young guinea pigs and demonstrate that under laboratory conditions mother and infant guinea pigs exhibit a nocturnal activity pattern.     

An MMPI-based empirical model of malingering and deception

The empirically-based model of malingering and deception described by Rogers (1984b) was operationalized using MMPI and clinical interview data. Subjects (N = 159) were patients committed to an inpatient forensic hospital as ‘Incompetent to Stand Trial’ or ‘Not Guilty by Reason of Insanity’. Inter-rater reliability was acceptable for the 11 criteria used to define response styles. Each subject was categorized into one of five response style groups: ‘Reliable’, ‘Malingering’, ‘Defensive’, ‘Irrelevant’, or ‘Unclassifiable’. Factor analysis of the rating criteria yielded four factors, three of which are comparable to the assigned groups, providing some validation for the constructs underlying these groups.     

The stroop effect and the myth of automaticity

A widespread view in cognition is that once acquired through extensive practice, mental skills such as reading are automatic. Lexical and semantic analyses of single words are said to be uncontrollable in the sense that they cannot be prevented. Over the past 60 years, apparently convincing support for this assumption has come from hundreds of experiments in which skilled readers have processed an irrelevant word in the Stroop task despite explicit instructions not to, even when so doing would hurt color identification performance. This basic effect was replicated in two experiments, which also showed that a considerable amount of semantic processing is locally controlled by elements of the task. For example, simply coloring a single letter instead of the whole word eliminated the Stroop effect. This outcome flies in the face of any automaticity account in which specified processes cannot be prevented from being set in motion, but it is consistent with the venerable idea that mental set is a powerful determinant of performance.     

Do worksite stress management programs attract the employees who need them and are they effective?

Employees who planned to attend a worksite stress management program (volunteers), those who planned not to attend (nonvolunteers), and those who had participated in worksite stress management training were assessed on the variables of work stressors, perceived stress, and organizational spontaneity (extrarole) behavior. Twelve hundred hospital employees were randomly selected from seven VA hospitals that had been offering a stress management program for at least 5 years. Participants received questionnaire packets in the mail and 461 (38%) of the employees responded. The results showed that volunteers reported significantly more perceived stress than the nonvolunteers. However, volunteers did not report greater frequency or intensity of work stressors. Also, respondents who had participated in past stress training reported less perceived stress than volunteers and significantly more organizational spontaneity behavior than respondents who had not participated in past stress training. These findings suggest that employees who plan to attend stress training have the greatest need and that the stress intervention reduces perceived stress levels and, possibly, affects work behavior.