Time but not force is transferred between ipsilateral upper and lower limbs

The authors compared the force and time endpoint accuracy of goal-directed ipsilateral upper and lower limb isometric contractions and determined the components of motor performance that can be transferred from 1 limb to the other after practice. Ten young adults (27.4 +/- 4.4 years) performed 100 trials that involved their matching peak force to a force-time target with ankle dorsiflexor and elbow flexor muscles. The peak force error and variability was greater for ankle dorsiflexor contractions than for elbow flexor contractions, whereas the timing error and variability did not significantly vary with limb. There was transfer of timing, but not force, of motor output between upper and lower limbs. The timing error of the elbow flexor contractions decreased by 23% when those contractions were preceded by ankle dorsiflexor contractions, and the timing error of the ankle dorsiflexors decreased by 24% when those contractions were preceded by elbow flexor contractions. These finding therefore suggest that timing of an aiming isometric contraction may be organized at a common part of the brain for the upper and lower limbs.     

Multiple social identities and reactivity to daily stress among ethnically diverse young adults

In a sample of 181 young adults from Filipino, European, Latin and Asian American backgrounds, cluster analytic techniques were employed to determine how ethnic, American, family, and religious identity interact to form unique identity configurations. Four clusters emerged: Many Social Identities (MSI), Blended/Low Religious (B/LR), Blended/Low Ethnic and American (B/LEA), and Few Social Identities (FSI). Based on daily diary reports over 14 days, differential reactivity to daily stressors was examined on feelings of anxiety and positive mood. Results suggested that individuals in the MSI, B/LR and B/LEA clusters reported increased anxiety on days when they experienced more stressors. In addition, individuals in the MSI and B/LR clusters reported feeling less positive when they experienced stressors. Multiple identity configurations and their implications for stress reactivity are discussed.     

Prenatal dopamine and neonatal behavior and biochemistry

Depressed pregnant women (N=126) were divided into high and low prenatal maternal dopamine (HVA) groups based on a tertile split on their dopamine levels at 20 weeks gestation. The high versus the low dopamine group had lower Center for Epidemiological Studies-Depression Scale (CES-D) scores, higher norepinephrine levels at the 20-week gestational age visit and higher dopamine and serotonin levels at both the 20- and the 32-week gestational age visits. The neonates of the mothers with high versus low prenatal dopamine levels also had higher dopamine and serotonin levels as well as lower cortisol levels. Finally, the neonates in the high dopamine group had better autonomic stability and excitability scores on the Brazelton Neonatal Behavior Assessment Scale. Thus, prenatal maternal dopamine levels appear to be negatively related to prenatal depression scores and positively related to neonatal dopamine and behavioral regulation, although these effects are confounded by elevated serotonin levels.     

Vagal activity, early growth and emotional development

A review of the research on infant vagal tone suggests that vagal activity is associated with both infant growth and infant socioemotional development. Vagal activity has been noted to increase following the stimulation of pressure receptors as in massage therapy. Vagal activity, in turn, stimulates gastric motility which mediates weight gain in infants. Vagal activity has also been notably elevated during synchronous mother–infant interactions and positive affect, providing confirmatory data for the Porges “social engagement system” model. In contrast, low vagal activity has been noted in prenatally depressed mothers (and prenatally angry and anxious mothers) and their infants, as well as in children with autism. These studies highlight the relations between vagal activity and the social behaviors of attentiveness, facial expressions and vocalizations.     

Prenatal predictors of maternal and newborn EEG

Ninety-two mothers were recruited at a prenatal ultrasound clinic at which time they were given the CES-D for depression and the State-Trait Anxiety Inventory, and their urines were assayed for cortisol, norepinephrine, epinephrine, dopamine, and serotonin. At the neonatal period the mothers and neonates were assessed on frontal EEG asymmetry. Correlation analyses revealed the following: (1) the mothers’ frontal asymmetry was negatively related to prenatal depression (CES-D) symptoms, negatively related to prenatal norepinephrine levels and positively related to prenatal serotonin levels; (2) the frontal asymmetry of the newborn was positively correlated with the mothers’ frontal asymmetry and negatively correlated with the mothers’ prenatal depression (CES-D) symptoms and negatively correlated with the mothers’ prenatal state anxiety scores. The neonates’ EEG frontal asymmetry was also, like the mother's, negatively related to prenatal maternal norepinephrine and positively related to prenatal maternal serotonin.     

Factors Influencing Experienced Distress and Attitude Toward Trauma by Emergency Medicine Practitioners

Authors explored whether the dose-response relationship evident in PTSD also applied to cases of vicarious trauma and, if so, which variables serve to moderate such reactions. This study examined the surveyed responses of emergency care workers in a group geographically near the September 11, 2001 New York terrorist site, comparing the results to a group of emergency care workers geographically distant from the terrorist site. Study results lend support to the presence of a dose-response relationship within vicarious traumatization. Specific variables associated with higher distress levels for practitioners included the discipline of the practitioner, treating an injured victim, and personally knowing a victim of the New York terrorist attacks. Past training related to vicarious traumatization was not associated with lower distress levels for practitioners. In addition, practitioners' awareness and interest in psychological issues related to trauma appear to have been enhanced by geographic proximity to the New York terrorist attacks.     

A comparison of differential reinforcement and noncontingent reinforcement for the treatment of a child's multiply controlled problem behavior

Noncontingent reinforcement (NCR) and differential reinforcement of other behavior (DRO) with escape as the reinforcer were evaluated after an initial functional analysis indicated the problem behaviors exhibited by a 7 year old child were maintained by escape. When NCR and DRO did not decrease the problem behaviors, a second functional analysis was conducted and showed that the behaviors were maintained by attention and escape. DRO with attention and escape as reinforcers was compared to NCR with attention and escape as reinforcers for the treatment of the child's multiply controlled behavior problems. Results showed that DRO and NCR were both effective at reducing the problem behavior to low levels and increasing compliance. Copyright © 2003 John Wiley & Sons, Ltd.     

Programming a randomized dependent group contingency and common stimuli to promote durable behavior change

Low levels of academic engagement may impede students’ acquisition of skills. Intervening on student behavior using group contingencies may be a feasible way to increase academic engagement during group instruction. The current study examined the effect of a randomized dependent group contingency on levels of academic engagement for second‐grade participants receiving small‐group reading and writing instruction. The results showed that a randomized dependent group contingency increased the academic engagement of primary participants and several of the other participants during small‐group instruction. The findings also showed that high levels of academic engagement were maintained when common stimuli were present and the dependent group contingency was withdrawn.     

Psychopathic Personality Traits as Protective Factors against the Development of Post-Traumatic Stress Disorder Symptoms in a Sample of National Guard Combat Veterans

Military personnel often experience post-traumatic stress symptoms following exposure to combat. Personality traits have been identified as possible protective and risk factors in the development of post-traumatic stress disorder (PTSD), and examination of the association between PTSD and personality characteristics provides further insight into this heterogeneous disorder. Psychopathy, frequently conceptualized as collection of pathological personality disturbances relating to deficits in emotionality, empathy, and inhibitory control, includes within its defining features components that may be adaptive in certain situations. In the current study, we sought to expand upon the literature related to personality and PTSD by exploring psychopathic traits as resiliency factors in a military sample. Specifically, facets of psychopathy were analyzed as moderators of the association between combat experience and symptoms of post-traumatic stress disorder within a sample of 292 combat-exposed National Guard and Reserve (NGR) service members. Results indicated that the relationship of combat exposure with PTSD decreased as rates of interpersonal-affective psychopathic traits increased. Impulsive-antisocial traits were also found to moderate the association between combat experience and PTSD, though interestingly there was a similar decrease in magnitude with higher levels of these traits. These findings suggest that particular components of psychopathy may serve as protective factors against the development of PTSD symptomatology within this population.