A simple and inexpensive telemetry system for measuring deep body temperature in rodents

An easily constructed telemetry system for measuring deep body temperatures in rodents is described and data collected with the system is presented. The system allows continual monitoring of core temperature without interfering with concomitant behavioral or physiological measurements.     

The effect of repeated testing on judgement bias in domestic dogs (Canis familiaris)

Animal Cognition - Judgement bias paradigms are increasingly being used as a measure of affective state in dogs. Approach to an ambiguous stimulus is commonly used as a measure of affect, however,...     

Weber's Law influences numerical representations in rhesus macaques (Macaca mulatta)

We present the results of two experiments that probe the ability of rhesus macaques to match visual arrays based on number. Three monkeys were first trained on a delayed match-to-sample paradigm (DMTS) to match stimuli on the basis of number and ignore continuous dimensions such as element size, cumulative surface area, and density. Monkeys were then tested in a numerical bisection experiment that required them to indicate whether a sample numerosity was closer to a small or large anchor value. Results indicated that, for two sets of anchor values with the same ratio, the probability of choosing the larger anchor value systematically increased with the sample number and the psychometric functions superimposed. A second experiment employed a numerical DMTS task in which the choice values contained an exact numerical match to the sample and a distracter that varied in number. Both accuracy and reaction time were modulated by the ratio between the correct numerical match and the distracter, as predicted by Weber's Law.     

Adult social behavioral effects of heavy adolescent marijuana use among African Americans

The authors examined the effects of heavy adolescent marijuana use on employment, marriage, and family formation and tested both dropping out of high school and adult marijuana use as potential mediators of these associations among a community sample of African Americans followed longitudinally from age 6 to age 32-33. They used propensity score matching to reduce selection bias when estimating the effects of heavy adolescent marijuana use. Logistic regression results on the sample matched on sex, and early demographic and behavioral variables showed that adolescent marijuana use has adult social behavioral consequences: Use of marijuana 20 times or more during adolescence was associated with being unemployed and unmarried in young adulthood and having children outside of marriage for both males and females. Dropping out of high school and more frequent adult marijuana use seem to be important parts of the pathway from adolescent marijuana use to negative life outcomes.     

Coping styles and personality: a biometric analysis

Previous research suggests that coping styles are modestly heritable and that this genetic influence is shared in large part with genetic influences on personality. To test this hypothesis, we estimated the heritable basis of the Coping Inventory for Stressful Situations in a sample of 91 monozygotic and 80 dizygotic twin pairs. Task-oriented, emotion-oriented, and social diversion coping styles were modestly heritable (h(2)=.17 to .20), whereas the use of distraction appeared to be influenced solely by environmental factors. Multivariate analyses showed that genetic contributions to coping styles were, at best, only modestly related to genetic contributions to personality (r=-.03 to .35). Environmental contributions to personality were unrelated to environmental factors in coping style. These results suggest that coping style is not merely a manifestation of basic personality traits but does support the possibility that the genetic factors in personality influences have a modest influence on an individual's preferred coping style or strength (e.g., rigidity vs flexibility).     

Suicidal behavior among youth with severe emotional disturbance

The purpose of this study was to replicate an investigation of risk behaviors associated with suicidal behavior in public high school students, in a population of high school age youth with severe emotional disturbance (SED). Subjects for the study were clients of the South Carolina Continuum of Care (COC) (N=83). Information on suicidal thoughts and acts, aggressive behaviors, substance use and physical recklessness was gathered using a modified version of the self-report National Youth Risk Behavior Survey. Four percent of the youth reported seriously considering suicide, 8% reported planning how they would attempt suicide, 10% reported actually attempting suicide at least once, and 6% reported attempts requiring medical treatment Of the 13 youth who reported attempting suicide, four (31%) did not report planning an attempt. All suicidal behaviors except thoughts occurred more in girls than boys with SED. Alcohol and illicit drug use were associated with suicidal behavior, with larger odds ratios for attempts than for thoughts/plans. Youth with SED who use alcohol and illicit substances are particularly at risk of suicidal behavior. A high index of suspicion is appropriate when evaluating suicidal risk in girls with SED, especially in the presence of known alcohol or substance use.Continuum of Care for Emotionally Disturbed Children Division, S. C. Office of the Governor.     

Delayed matching by fornix-transected monkeys: The sample, the push and the bait

In the acquisition event of ordinary delayed matching to sample the monkey sees a sample, displaces it, and finds a food reward underneath; subsequently the retention test consists of a choice between that sample and a distractor, and the strength of the memory laid down by the acquisition event may be assessed by the correctness of choice at the retention test. The present experiments varied the acquisition events and examined the effect of those variations on normal and fornix-transected monkeys' memory. One variation was to proceed as normally but never to bait the sample at acquisition; this variation allowed assessment of the role of the food reward in ordinary matching. Another was to present the sample, baited and to be displaced, as normally, but to present also the distractor, baited but not requiring to be displaced, in a second acquisition event; this “push-match” variation allowed assessment of memory for the displacement. The main result from normal monkeys was that matching to unbaited samples was learned much faster than matching to baited samples. Following fornix transection, final performance levels in matching to baited and to unbaited samples were unimpaired but push-match showed a permanent deficit. These results support earlier indications that fornix-transected monkeys have normal sensory memory but are deficient in the memory of instrumental responses.     

Correlations for the Stroop Color and Word Test with measures of reading and language achievement

The present investigation examined the relationships for scores on the Stroop Color and Word Test with measures of reading and language achievement within an adult population. The Stroop Color and Word Test, Nelson-Denny Reading Test, Woodcock-Johnson Psycho-Educational Battery-Revised, and Wide Range Achievement Test-3 were administered to 99 men ranging in age from 18 to 27 years. Pearson product-moment correlations indicated that the Stroop Word task was positively associated with scores on the WRAT-3 Spelling task, the Woodcock-Johnson Basic and Broad Reading tasks, and the Nelson-Denny Rcading Rate and Comprehension tasks. These and other significant relationships were discussed in terms of possible implications regarding the assessment of reading achievement.