Effects of school‐based mindfulness training on emotion processing and well‐being in adolescents: evidence from event‐related potentials

In a non‐randomized controlled study, we investigated the efficacy of a school‐based mindfulness curriculum delivered by schoolteachers to older secondary school students (16–18 years). We measured changes in emotion processing indexed by P3b event‐related potential (ERP) modulations in an affective oddball task using static human faces. ERPs were recorded to happy and sad face oddballs presented in a stimulus stream of frequent faces with neutral expression, before and after 8 weeks of mindfulness training. Whilst the mean amplitude of the P3b, an ERP component typically elicited by infrequent oddballs, decreased between testing sessions in the control group, it remained unchanged in the training group. Significant increases in self‐reported well‐being and fewer doctor visits for mental health support were also reported in the training group as compared to controls. The observed habituation to emotional stimuli in controls thus contrasted with maintained sensitivity in mindfulness‐trained students. These results suggest that in‐school mindfulness training for adolescents has scope for increasing awareness of socially relevant emotional stimuli, irrespective of valence, and thus may decrease vulnerability to depression.     

The effects of chlordiazepoxide on the development of adjunctive drinking in rats

Intermittent delivery of food pellets induces high levels of adjunctive drinking in rats, a pattern of behaviour which some have suggested is due to emotional arousal. In this experiment, however, chronic administration of a dose of chlordiazepoxide, a minor tranquillizer, did not prevent the development of adjunctive drinking after food pellets delivered at 1-min intervals. Indeed, the drug was found slightly to enhance the development of drinking, an effect assumed to be due to the drug's ability to facilitate the performance of several patterns of responding. When chlordiazepoxide was withdrawn a disruption in the pattern of adjunctive drinking was observed.     

Coping Self-Efficacy as a Mediator of Distress Following a Natural Disaster

Social-cognitive theory and conservation-of-resources theory were utilized to understand individual differences in psychological response to natural disaster. Coping self-efficacy, lost resources, social support, and optimism were assessed along with demographic variables in predicting distress following Hurricane Opal. Participants included 67 residents of Okaloosa County, Florida. Multiple regression analyses indicated that coping self-efficacy was the strongest predictor of general distress and trauma-related distress. Loss of resources and gender were also important predictors of general distress. Path analyses demonstrated that lost resources directly influenced general distress, social support, optimism, and coping self-efficacy. These analyses also indicated that coping self-efficacy perceptions mediated the relationships between loss of resources and trauma-related distress, social support and both trauma and general distress, and optimism and both types of distress. Theoretical implications are discussed.     

Repression following a series of natural disasters: Immune and Neuroendocrine correlates

The influence of repression on peripheral blood lymphocyte surface markers and diurnal decline in salivary cortisol following multiple disasters was examined. Participants were sampled at 2 to 8 weeks after a severe fire and flood, and again 1 year later. High distress, low distress, and repression groups were formed utilizing self-reported distress and systolic blood pressure during a disaster recall interview. A main effect for group was identified for CD56⁺ cells (NK cells), with repressors and high distress participants demonstrating lower percentage of NK cells than low distress participants. At Time 1 repressors demonstrated significantly higher percentage of CD56⁺CD69⁺ cells (activated NK cells) than high and low distress participants. From Time 1 to Time 2, repressor participants showed a significant decline in the percentage of activated NK cells. Repressors demonstrated attenuated decline in salivary cortisol compared to low distress participants. Health implications for disaster recovery are discussed.     

Controlling variability

In human motor control, there is uncertainty in both estimation of initial sensory state and prediction of the outcome of motor commands. With practice, increasing precision can often be achieved, but such precision incurs costs in time, effort, and neural resources. Therefore, motor planning must account for variability, uncertainty, and noise, not just at the endpoint of movement but throughout the movement. The author presents a mathematical basis for understanding the time course of uncertainty during movement. He shows that it is possible to achieve accurate control of the endpoint of a movement even with highly inaccurate and variable controllers. The results provide a first step toward a theory of optimal control for variable, uncertain, and noisy systems that must nevertheless accomplish real-world tasks reliably.     

Genetic differences in the mouse defense test battery

The mouse defense test battery (MDTB) has been designed to examine anxiogenic- or anxiolytic-like properties of psychoactive drugs through effects on specific defensive behaviors. In the present study, the MDTB was used to evaluate the potential contribution of genetic factors to these behaviors. The data revealed pronounced differences in several defense reactions among four inbred strains (BALB/c, C57BL/6, CBA, DBA/2) and one outbred (Swiss) mouse line. Thus, when subjects were introduced into the apparatus, Swiss and C57BL/6 displayed the highest levels of horizontal and vertical activities, while BALB/c and DBA/2 mice showed intermediate and CBA low activity rates. When subjects were chased by the rat, C57BL/6 mice used flight as the dominant defense strategy, while the defensive responses of BALB/c, C57BL/6, and DBA/2 mice consisted of flight reactions and risk assessment activities. However, when flight or escape was not possible, risk assessment became the predominant feature of the defense repertoire in the C57BL/6 mice. When defensive threat/attack behaviors were required, Swiss, BALB/c, DBA/2, and C57BL/6 mice showed very similar reactions in terms of the magnitude of the responses observed. CBA mice were poorly defensive in all these test situations. Finally, after the rat was removed from the test apparatus, Swiss, DBA/2, and C57BL/6 mice displayed more vertical activities than BALB/c mice. These latter, however, showed an increased level of ambulation compared to the activity recorded before the rat exposure. Together, these findings indicate that genetic factors contribute to defensive behaviors in this animal model of anxiety. The different behavioral profiles displayed by the strains used here may provide the means to obtain a better insight into the neurobehavioral mechanisms involved in anxiety-related disorders. Aggr. Behav. 23:19–31, 1997. © 1997 Wiley-Liss, Inc.     

The effects of d-amphetamine on the temporal control of operant responding in rats during a preshock stimulus.

The operant behavior of six rats was maintained by a random-interval schedule of reinforcement. Three-minute periods of noise were superimposed on this behavior, each period ending with the delivery of an unavoidable shock. Overall rates of responding were generally lower during the periods of noise than in its absence (conditioned suppression). These suppressed response rates also exhibited temporal patterning, with responding becoming less frequent as each noise period progressed. The effects of d-amphetamine on this behavioral baseline were then assessed. In four animals the relative response rates during the noise and in its absence suggested that the drug produced a dose-related decrease in the amount of conditioned suppression. However, this effect was often due to a decrease in the rates of responding in the absence of the preshock stimulus, rather than to an increase in response rates during the stimulus. Temporal patterning in response rates during the preshock stimulus was abolished, an effect that was interpreted in terms of rate-dependent effect of d-amphetamine. This study thus extends rate-dependent analyses of the effects of amphetamines to the patterns of operant behavior that occur during a preshock stimulus, and which have been discussed in terms of the disrupting effects of anxiety on operant behavior.