Changes in the incidence of nocturnal bruxism in college students: 1966-1989

The frequency of self-reported nocturnal bruxism in three large samples of college undergraduates was compared as a means of assessing change in the incidence of this disorder since 1966. We found the incidence of nocturnal bruxism had increased from 5.1% to 20.5% in college students over the period covered by these studies.     

Vocal-manual trade-offs in hemispheric sharing of human performance control

Experiment 1 established the linear ordering of performance and rated difficulty of three finger-sequencing tasks. Experiment 2 embedded these tasks within a dual-task paradigm employing vocalization of words and nonwords as concurrent activities. Concurrent vocal activity interfered with right-more than with left handed performance, and this lateralized interference effect increased monotonically with increased sequence difficulty. Results are discussed in terms of hemispheric sharing of dual task performance control.     

Lateralized concomitants of human handedness

Literature was reviewed concerning lateral asymmetries of brain and behavior in normal and pathological populations of left-and right-handers. Cerebral asymmetries of structure and function are less pronounced in left-handers as a group than in right-handers as a group, and variability is greater in left-handers.     

Coping with a major stressor: differences between habitual short- and longer-sleepers.

We compared the coping strategies of 39 short-sleepers and 33 longer-sleepers to the stresses associated with the October 17, 1989 San Francisco Bay Area earthquake using their responses to the eight scales of the Ways of Coping Questionnaire. Over-all, the short-sleepers scored significantly higher on this questionnaire and in general, the pattern of their responses was consistent with inferences that could be drawn from a 1972 paper by Hartmann, Baekeland, and Zwilling.     

A comparative evaluation of parent-training interventions for families of chronic delinquents

Fifty-five families of chronically offending delinquents were randomly assigned to parent-training treatment or to service traditionally provided by the juvenile court and community. The families in the parent-training group received an average of 44.8 hours of professional contact (23.3 hours of which were phone contacts), and each control group family received treatment estimated at more than 50 hours on the average. Comparisons of police contact data at baseline and subsequent years for the two groups showed that subjects in both groups demonstrated reduced rates of offending during the followup years. The finding most relevant was significant treatment-by-time effect for offense rates, with most of this effect accounted for by a greater reduction in serious crimes for the experimental group during the treatment year, and a similar reduction of the community control group occurring in the first of three followup years. These early decrements in offense rates persisted during followup for both groups. Throughout the study, boys in the experimental group spent significantly less time in institutional settings than did boys in the control group. Parent training had a significant impact, but the reduction in offending was produced at very high emotional cost to staff. Although it is clear that this population requires substantial treatment resources, this study underscores the need for more work on prevention.Research for this paper was supported by grant MH 37938 from the Center for Studies of Antisocial and Violent Behavior, National Institute of Mental Health (NIMH), U.S. Public Health Service (PHS). The writing was supported in part by grants MH 17126 and MH 37940 from the same Center, grant DA 05304 from the National Institute of Drug Abuse, U.S. PHS., and grant MH 38730 from the Child and Adolescent Disorders Research Branch, NIMH, U.S. PHS. The authors gratefully acknowledge the enduring commitment of the treatment staff that made this study possible: Patricia Chamberlain, Marion Forgatch, and Kate Kavanagh.     

Counting eliminates the repetition effect in judgments of temporal duration.

College student subjects estimated the duration of time intervals (8–54 sec) by counting or not (N=35 per group). Counting eliminated the repetition effect (a decline in the magnitude of estimations across trials), and resulted in a truncation of the psychophysical function. The former result was interpreted as contrary to Treisman's (1963) model. The latter result was attributed to the effortfulness of counting, which was established in a subsequent experiment.