Effect of the interintromission interval on lordotic response and attack latency in golden hamsters (Mesocricetus auratus)

After 12-15 ejaculatory series, each consisting of several short intromissions (2- to 3-s vaginal penetration) and an ejaculation, male golden hamsters adopt an altered copulatory pattern consisting of long intromissions (5- to 25-s penetration with intravaginal thrusting). Receptivity declines and the tendency for the female to attack the male increases at about the time of this shift in copulatory pattern. Because the mean interintromission interval (III) between short intromissions is about 8 s compared to 100 s between long intromissions, it is possible that females detect this difference and adjust their mating accordingly. When the III between short intromissions from a rested male was experimentally increased to 100 s by use of a halter and lead device, the duration of lordosis was significantly less than that displayed by females paired with control males (8-s III) and virtually the same as that displayed by females paired with males that produced only long intromissions. This suggests that the female uses the temporal patterning of intravaginal stimulation as one criterion for terminating mating with a particular male.     

Perceptual organization of acoustic stimuli by budgerigars (Melopsittacus undulatus): III. Contact calls

We trained budgerigars by operant conditioning to discriminate among a set of contact calls in a same-different task and analyzed response latencies from this task by using multidimensional-scaling (MDS) and cluster-analysis procedures. Humans listened to the same calls and indicated the similarity between pairs of calls by a direct rating procedure. An MDS program (sindscal) was used to arrange these complex acoustic stimuli in multidimensional space reflecting perceptual organization. Multiple regression techniques were used to identify the acoustic characteristics of contact calls that were correlated with the perceptual dimensions obtained from MDS. A number of spectral characteristics (e.g., peak frequency, rate of frequency modulation, and concentration of spectral energy) emerged as important for both budgerigars and humans, but the relative salience of these cues differed for the two species. Additional tests with two groups of budgerigars--cagemates and noncagemates--showed that experience with calls can change the salience of various acoustic characteristics used for perceptual organization and individual recognition.     

Choosing Between Parametric and Nonparametric Tests

A fundamental analysis decision confronting researchers in psychology and education is the choice between parametric and nonparametric tests. Despite the statistical and substantive implications of this important decision, many researchers unerringly employ parametric tests and thus ignore the advantages of their nonparametric counterparts. One justification for this behavior has been the absence of guidelines for choosing between these procedures. A second has been the lack of a comprehensive nonparametric test that is computationally manageable. In this article, the author discusses several statistical and substantive criteria that can be used to choose between parametric and nonparametric tests. A non-parametric test capable of testing a number of statistical hypotheses using existing computer packages is also presented. Recommendations are made encouraging researchers to routinely use nonparametric tests in their data analytic work.     

Effect of social support on the stress-burnout relationship

Business organizations have become interested in recent years in the role of social support in reducing the negative effect of stress. The purpose of this research is to examine the effects of two types of social support (i.e., job and life support) on the relationships between job and life stress and burnout. Participants consisted of 270 males and 254 females. For both males and females job stress and life stress correlate positively with burnout, while job and life support were negatively correlated with burnout. The hypothesis that social support would moderate stress-burnout relationships was not supported. Neither job support nor life support moderated job stress or life stress-burnout relationships. Females exhibited significantly higher levels of burnout, job stress, and life stress than males; however, there was no difference between males and females in the amount of social support received.     

A longitudinal study of the psychosocial impact of stroke on primary support persons

We investigated longitudinally the effects of a stroke on the social support systems and well-being of the patient's primary support person, both acutely and as the condition stabilized. Individuals who had suffered a first stroke and a primary support person participated in two waves of data collection, carried out in 6-month intervals beginning 7 weeks after the stroke. Our data show that the prevalence of depressive symptoms is from 2 1/2 to 3 1/2 times higher than rates found among representative samples of middle-aged and elderly populations. Mean level of depression did not change over time, although level of optimism declined significantly. Multiple regression analyses showed that levels of depression and perceived burden in support persons are highly related to aspects of the stroke such as its severity, and that demographic variables such as age and income play a relatively minor role in attenuating these relations in the acute adjustment phase. However, from 7 to 9 months after the stroke, well-established demographic variables such as health, income, and age were significant predictors of depression. Individuals who were older and who had good health and higher incomes were least depressed.     

A content analysis of the conversational behavior of accepted and rejected children

The present study was designed to assess whether the conversational behavior of children separated into accepted, rejected, and mixed-status dyads differed along the dimensions of listening to, paying attention to, and indicating interest in their dyadic partner. Conversations of 40 third-grade dyads were analyzed as they occurred in a 2- min waiting period and a 4- min conversation period. Seventeen categories of verbal behaviors that indexed these dimensions were used as content codes. Multivariate analyses of variance performed on the observational data yielded significant main effects for status, sex, and experimental condition. Results are interpreted in terms of previous social skills research, and suggestions for future research are offered.     

Forgetting of pictures over a long retention interval in young and older adults

Young and older adults were presented with pictures for study. Their recognition of the information was tested at five retention intervals: immediately, and 48 hr, 1 week, 2 weeks, and 4 weeks later. The main finding of interest was that picture recognition did not show an age-related decline until the 1-week retention interval.     

Different patterns of cognitive slowing produced by Alzheimer's disease and normal aging

Aging has previously been shown to produce a generalized proportional slowing of all cognitive operations. In contrast, the present results suggested that Alzheimer's disease produces a disproportionate reduction in the speed with which patients carry out one or more mental operations. The tasks that demented patients found particularly difficult involved either a self-directed search of their lexicon or the use of familiarity information.     

Effects of male social status on reproductive success and on behavior in mice (Mus musculus)

Differences in reproduction as well as in behavior in the presence of females were evaluated according to dominant and subordinate male rank in albino mice, in the temporary absence of each male's antagonist. Dominant males reproduced more successfully than subordinate males. Subordinate males were generally inactive, except for displacement activities, during the first 15 min they were exposed to female partners. These findings suggest that mechanisms other than male-male interference or mating order may be operating or influencing behavior and reproductive results.     

Age analysis of cognitive-behavioral group therapy for chronic pain outpatients

This study explored the effectiveness, in terms of age of the client, of a 10-week cognitive-behavioral group therapy (stress inoculation training) for chronic pain. A total of 69 outpatients between the ages of 27 and 80 (M = 52.74 years, SD = 14.40) with diverse types of chronic pain were assigned randomly to immediate or wait-list-delayed therapy. Self-report measures of pain, activities, coping, and the use of medications and other physical pain control techniques were obtained at baseline, during therapy, and at 1- and 6-month follow-up. Treatment decreased the degree to which pain interfered with activity, increased ability to cope with pain, and decreased use of some medications and other physical treatments. It had little effect on perceived pain intensity. Gains were maintained through 6-month follow-up. Age was unrelated to outcome. Stress inoculation training appears to be an effective method of ameliorating the interference of chronic pain with the daily activities of life for adults of all ages.