Faculty Bibliography

Sensitivity to facial and vocal emotion is fundamental to children's social competence. Previous research has focused on children's facial emotion recognition, and few studies have investigated non-linguistic vocal emotion processing in childhood. We compared facial and vocal emotion recognition and processing biases in 4- to 11-year-olds and adults. Eighty-eight 4- to 11-year-olds and 21 adults participated. Participants viewed/listened to faces and voices (angry, happy, and sad) at three intensity levels (50%, 75%, and 100%). Non-linguistic tones were used. For each modality, participants completed an emotion identification task. Accuracy and bias for each emotion and modality were compared across 4- to 5-, 6- to 9- and 10- to 11-year-olds and adults. The results showed that children's emotion recognition improved with age; preschoolers were less accurate than other groups. Facial emotion recognition reached adult levels by 11 years, whereas vocal emotion recognition continued to develop in late childhood. Response bias decreased with age. For both modalities, sadness recognition was delayed across development relative to anger and happiness. The results demonstrate that developmental trajectories of emotion processing differ as a function of emotion type and stimulus modality. In addition, vocal emotion processing showed a more protracted developmental trajectory, compared to facial emotion processing. The results have important implications for programmes aiming to improve children's socio-emotional competence.

Research on the effects of adolescent employment on primarily middle-class youth suggests that intense employment, working more than 15 or 20 hours during the school year, is associated with increased participation in risky behavior. Despite these findings, scholars who focus on the development of youth living in low-income urban areas often hypothesize that adolescent employment will have beneficial effects on this population. There is some evidence that adolescent employment is associated with increased educational achievement and adult employment for low-income urban youth. The impact of adolescent employment on future engagement in risky behavior across levels of neighborhood deprivation and employment intensity was investigated on a sample of 1,057 adolescents from the Project on Human Development in Chicago Neighborhoods, a longitudinal study of neighborhood effects on development. After controlling for individual characteristics, intense employment during adolescence did predict increased use of cigarettes and alcohol and having a greater number of sexual partners 2 years after employment was measured. There were no significant interactions between neighborhood SES and adolescent employment status on involvement in risky behavior. These findings suggest that intense adolescent employment is associated with detrimental developmental outcomes for youth regardless neighborhood context.

Adult neurogenesis, the generation of new neurons in the adult brain, occurs in the hippocampal dentate gyrus (DG) and the olfactory bulb (OB) of all mammals, but the functions of these new neurons are not entirely clear. Originally, adult-born neurons were considered to have excitatory effects on the DG network, but recent studies suggest a net inhibitory effect. Therefore, we hypothesized that selective removal of newborn neurons would lead to increased susceptibility to the effects of a convulsant. This hypothesis was tested by evaluating the response to the chemoconvulsant kainic acid (KA) in mice with reduced adult neurogenesis, produced either by focal X-irradiation of the DG, or by pharmacogenetic deletion of dividing radial glial precursors. In the first 4 hrs after KA administration, when mice have the most robust seizures, mice with reduced adult neurogenesis had more severe convulsive seizures, exhibited either as a decreased latency to the first convulsive seizure, greater number of convulsive seizures, or longer convulsive seizures. Nonconvulsive seizures did not appear to change or they decreased. Four-21 hrs after KA injection, mice with reduced adult neurogenesis showed more interictal spikes (IIS) and delayed seizures than controls. Effects were greater when the anticonvulsant ethosuximide was injected 30 min prior to KA administration; ethosuximide allows forebrain seizure activity to be more easily examined in mice by suppressing seizures dominated by the brainstem. These data support the hypothesis that reduction of adult-born neurons increases the susceptibility of the brain to effects of KA.

Besides the crucial role of genetic susceptibility in the development of early-onset obesity, it has been shown that feeding behavior could contribute to increased body weight. A significant association between obesity/overweight and ADHD has been reported, suggesting that these two conditions, despite their heterogeneity, might share common molecular pathways. Although the co-occurrence of obesity and ADHD is increasingly supported by empirical evidence, the complex pathogenetic link between these two conditions is still unclear. Here, we focus on the relationship between MC4R gene mutations and ADHD in children with early-onset obesity. Mutations in the gene MC4R lead to the most common form of monogenic obesity. We hypothesize that dysregulated eating behavior in a subset of patients with MC4R mutation might be due to comorbid ADHD symptoms, underpinned by abnormal reward mechanisms. Therefore, we speculate that it is possible to prevent obesity in a subset of patients with MC4R mutation, even if these patients are genetically programmed to "be fat", via an appropriate treatment of ADHD symptoms. We hope that our paper will stimulate further studies testing if the early screening for ADHD symptoms and their appropriate treatment may be an effective way to prevent obesity in a subset of children with MC4R mutation.

Abstract There is a well-established and growing body of evidence from research that adolescents who commit crimes differ in many regards from their adult counterparts and are more susceptible to the negative effects of adjudication and incarceration in adult criminal justice systems. The age of criminal court jurisdiction in the United States has varied throughout history; yet, there are only two remaining states, New York and North Carolina, that continue to automatically charge 16 year olds as adults. This review traces the statutory history of juvenile justice in these two states with an emphasis on political and social factors that have contributed to their outlier status related to the age of criminal court jurisdiction. The neurobiological, psychological, and developmental aspects of the adolescent brain and personality, and how those issues relate both to a greater likelihood of rehabilitation in appropriate settings and to greater vulnerability in adult correctional facilities, are also reviewed. The importance of raising the age in New York and North Carolina not only lies in protecting incarcerated youths but also in preventing the associated stigma following release. Mental health practitioners are vital to the process of local and national juvenile justice reform. They can serve as experts on and advocates for appropriate mental health care and as experts on the adverse effects of the adult criminal justice system on adolescents.

This study investigated the predictive relations between externalizing behavior, peer preference and friendship quantity, and bully status and victim status among children becoming acquainted with one another for the first time. Children ages 6.8-9.8 years (24 with Attention-Deficit/Hyperactivity Disorder; 113 typically developing; 72 girls) attended a 2-week summer day camp grouped into same-age, same-sex classrooms with previously unacquainted peers. Externalizing behavior (via parent and teacher ratings) was measured before the start of camp; peer preference and friendship quantity (via peer nominations) were measured in the middle of camp, and bully status and victim status (via peer nominations) were measured at the end of camp. Low peer preference mediated the positive association between externalizing behavior and bully status. Both peer preference and friendship quantity moderated the relation between externalizing behavior and bully status as well as between externalizing behavior and victim status; whereas high peer preference protected against both bully status and victim status, friendship quantity protected against victim status but exacerbated bully status. Some gender differences were found within these pathways. Peer preference, compared to friendship quantity, appears to have a more consistently protective role in the relation between externalizing behavior and bully status as well as victim status.

Many computational models assume that reinforcement learning relies on changes in synaptic efficacy between cortical regions representing stimuli and striatal regions involved in response selection, but this assumption has thus far lacked empirical support in humans. We recorded hemodynamic signals with fMRI while participants navigated a virtual maze to find hidden rewards. We fitted a reinforcement-learning algorithm to participants' choice behavior and evaluated the neural activity and the changes in functional connectivity related to trial-by-trial learning variables. Activity in the posterior putamen during choice periods increased progressively during learning. Furthermore, the functional connections between the sensorimotor cortex and the posterior putamen strengthened progressively as participants learned the task. These changes in corticostriatal connectivity differentiated participants who learned the task from those who did not. These findings provide a direct link between changes in corticostriatal connectivity and learning, thereby supporting a central assumption common to several computational models of reinforcement learning. Hum Brain Mapp, 2014. (c) 2014 Wiley Periodicals, Inc.

Caregiver-associated cues, including those learned in abusive attachment, provide a sense of safety and security to the child. Here, we explore how cues associated with abusive attachment, such as maternal odor, can modify the enduring neurobehavioral effects of early-life abuse. Two early-life abuse models were used: a naturalistic paradigm, where rat pups were reared by an abusive mother; and a more controlled paradigm, where pups underwent peppermint odor-shock conditioning that produces an artificial maternal odor through engagement of the attachment circuit. Animals were tested for maternal odor preference in infancy, forced swim test (FST), social behavior, and sexual motivation in adulthood-in the presence or absence of maternal odors (natural or peppermint). Amygdala odor-evoked local field potentials (LFPs) via wireless electrodes were also examined in response to the maternal odors in adulthood. Both early-life abuse models induced preference for the maternal odors in infancy. In adulthood, these early-life abuse models produced FST deficits and decreased social behavior, but did not change sexual motivation. Presentation of the maternal odors rescued FST and social behavior deficits induced by early-life abuse and enhanced sexual motivation in all animals. In addition, amygdala LFPs from both abuse animal models showed unique activation within the gamma frequency (70-90 Hz) bands in response to the specific maternal odor present during early-life abuse. These results suggest that attachment-related cues learned during infancy have a profound ability to rescue neurobehavioral dysregulation caused by early-life abuse. Paradoxically, abuse-associated cues seem to acquire powerful and enduring antidepressive properties and alter amygdala modulation.Neuropsychopharmacology advance online publication, 29 October 2014; doi:10.1038/npp.2014.266.