Ross E. Vanderwert

Timing of Intervention Affects Brain Electrical Activity in Children Exposed to Severe Psychosocial Neglect

Background Early psychosocial deprivation has profound effects on brain activity in the young child. Previous reports have shown increased power in slow frequencies of the electroencephalogram (EEG), primarily in the theta band, and decreased power in higher alpha and beta band frequencies in infants and children who have experienced institutional care. Methodology/Principal Findings We assessed the consequences of removing infants from institutions and placing them into a foster care intervention on brain electrical activity when children were 8 years of age. We found the intervention was successful for increasing high frequency EEG alpha power, with effects being most pronounced for children placed into foster care before 24 months of age. Conclusions/Significance The dependence on age of placement for the effects observed on high frequency EEG alpha power suggests a sensitive period after which brain activity in the face of severe psychosocial deprivation is less amenable to recovery.

Distinct eeg amplitude suppression to facial gestures as evidence for a mirror mechanism in newborn monkeys

At birth, human infants and newborns of other primate species demonstrate the capacity to attend and to respond to facial stimuli provided by a caregiver. Newborn infants are also capable of exhibiting a range of facial expressions. Identification of the neural underpinnings of these capacities represents a formidable challenge in understanding social development. One possible neuronal substrate is the mirror-neuron system assumed to activate shared motor cortical representations for both observation and production of actions. We tested this hypothesis by recording scalp EEG from 1- to 7-day-old newborn rhesus macaques who were observing and producing facial gestures. We found that 5–6 Hz EEG activity was suppressed both when the infants produced facial gestures and while they were observing facial gestures of a human experimenter, but not when they were observing nonbiological stimuli. These findings demonstrate the presence of neural reactivity for biological, communicatively relevant stimuli, which may be a likely signature of neuronal mirroring. The basic elements of the mirror-neuron system appear to operate from the very first days of life and contribute to the encoding of socially relevant stimuli.

The mirror mechanism and mu rhythm in social development

Since the discovery of mirror neurons (MNs) in the monkey there has been a renewed interest in motor theories of cognitive and social development in humans by providing a potential neural mechanism underlying an action observation/execution matching system. It has been proposed that this system plays a fundamental role in the development of complex social and cognitive behaviors such as imitation and action recognition. In this review we discuss what is known about MNs from the work using single-cell recordings in the adult monkey, the evidence for the putative MN system in humans, and the extent to which research using electroencephalography (EEG) methods has contributed to our understanding of the development of these motor systems and their role in the social behaviors postulated by the MN hypothesis. We conclude with directions for future research that will improve our understanding of the putative human MN system and the functional role of MNs in social development.

The use of near-infrared spectroscopy in the study of typical and atypical development

The use of functional near infrared spectroscopy (fNIRS) has grown exponentially over the past decade, particularly among investigators interested in early brain development. The use of this neuroimaging technique has begun to shed light on the development of a variety of sensory, perceptual, linguistic, and social-cognitive functions. Rather than cast a wide net, in this paper we first discuss typical development, focusing on joint attention, face processing, language, and sensorimotor development. We then turn our attention to infants and children whose development has been compromised or who are at risk for atypical development. We conclude our review by critiquing some of the methodological issues that have plagued the extant literature as well as offer suggestions for future research.

Attention to novelty in behaviorally inhibited adolescents moderates risk for anxiety

BACKGROUND Individual differences in specific components of attention contribute to behavioral reactivity and regulation. Children with the temperament of behavioral inhibition (BI) provide a good context for considering the manner in which certain components of attention shape behavior. Infants and children characterized as behaviorally inhibited manifest signs of heightened orienting to novelty. The current study considers whether this attention profile moderates risk for clinical anxiety disorders among adolescents with a history of BI. METHODS Participants were assessed at multiple time points for BI, beginning in early childhood. At adolescence, event-related potentials (ERPs) were recorded during a three-stimulus auditory novelty oddball task, which employed frequent standard and infrequent deviant tones as well as a set of complex, novel sounds. Clinical diagnosis was carried out using the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL). P3 and mismatch negativity (MMN) components were examined at midline frontal, central, and parietal electrode sites. RESULTS Individuals who displayed high levels of BI during childhood and increased P3 amplitude to novelty in adolescence were more likely to have a history of anxiety disorders compared to behaviorally inhibited adolescents with lower P3 amplitudes. Groups did not differ on measures of MMN. CONCLUSIONS Increased neural responses to novelty moderate risk for anxiety disorders amongst individuals with a history of BI.

Action Experience, More than Observation, Influences Mu Rhythm Desynchronization

Since the discovery of mirror neurons in premotor and parietal areas of the macaque monkey, the idea that action and perception may share the same neural code has been of central interest in social, developmental, and cognitive neurosciences. A fundamental question concerns how a putative human mirror neuron system may be tuned to the motor experiences of the individual. The current study tested the hypothesis that prior motor experience modulated the sensorimotor mu and beta rhythms. Specifically, we hypothesized that these sensorimotor rhythms would be more desynchronized after active motor experience compared to passive observation experience. To test our hypothesis, we collected EEG from adult participants during the observation of a relatively novel action: an experimenter used a claw-like tool to pick up a toy. Prior to EEG collection, we trained one group of adults to perform this action with the tool (performers). A second group comprised trained video coders, who only had experience observing the action (observers). Both the performers and the observers had no prior motor and visual experience with the action. A third group of novices was also tested. Performers exhibited the greatest mu rhythm desynchronization in the 8–13 Hz band, particularly in the right hemisphere compared to observers and novices. This study is the first to contrast active tool-use experience and observation experience in the mu rhythm and to show modulation with relatively shorter amounts of experience than prior mirror neuron expertise studies. These findings are discussed with respect to its broader implication as a neural signature for a mechanism of early social learning.

Psychosocial deprivation, executive functions, and the emergence of socio-emotional behavior problems

Early psychosocial deprivation can negatively impact the development of executive functions (EFs). Here we explore the impact of early psychosocial deprivation on behavioral and physiological measures (i.e., event-related potentials; ERPs) of two facets of EF, inhibitory control and response monitoring, and their associations with internalizing and externalizing outcomes in the Bucharest Early Intervention Project (BEIP; Zeanah et al., 2003). This project focuses on two groups of children placed in institutions shortly after birth and then randomly assigned in infancy to either a foster care intervention or to remain in their current institutional setting. A group of community controls was recruited for comparison. The current study assesses these children at 8-years of age examining the effects of early adversity, the potential effects of the intervention on EF and the role of EF skills in socio-emotional outcomes. Results reveal exposure to early psychosocial deprivation was associated with impaired inhibitory control on a flanker task. Children in the foster care intervention exhibited better response monitoring compared to children who remained in the institution on the error-related positivity (Pe). Moreover, among children in the foster care intervention those who exhibited larger error-related negativity (ERN) responses had lower levels of socio-emotional behavior problems. Overall, these data identify specific aspects of EF that contribute to adaptive and maladaptive socio-emotional outcomes among children experiencing early psychosocial deprivation.

Early social experience affects neural activity to affiliative facial gestures in newborn nonhuman primates

A fundamental issue in cognitive neuroscience is how the brain encodes the actions and intentions of others. The discovery of an action-production-perception mechanism underpinning such a capacity advanced our knowledge of how these processes occur; however, no study has examined how the early postnatal environment may shape action-production-perception. Here, we examined the effects of social experience on action-production-perception in 3-day-old rhesus macaques that were raised either with or without their biological mothers. We measured the neonatal imitation skills and brain electrical activity responses, while infants produced and observed facial gestures. We hypothesized that early social experiences may shape brain activity, as assessed via electroencephalogram suppression in the α band (5-7 Hz in infants, known as the mu rhythm) during action observation, and lead to more proficient imitation skills. Consistent with this hypothesis, the infants reared by their mothers were more likely to imitate lipsmacking (LS) - a natural, affiliative gesture - and exhibited greater mu rhythm desynchronization while viewing LS gestures than the nursery-reared infants. These effects were not found in response to tongue protrusion, a meaningless gesture, or a nonsocial control. These data suggest that socially enriched early experiences in the first days after birth increase brain sensitivity to socially relevant actions.

Modification of threat-processing in non-anxious individuals: a preliminary, behavioral and ERP study

BACKGROUND AND OBJECTIVES Previous research suggests that attention bias toward threat contributes to the development and maintenance of anxiety. The current study extends this work by mapping the neural correlates of experimentally-induced changes in attention bias. The study examines both behavioral and psychophysiological changes associated with experimentally-induced changes in threat bias. METHODS Thirty-four non-anxious female adults were randomly assigned to one of two conditions: training attention toward threat or placebo control. Attention bias was assessed and trained via a modified dot-probe task. Participants completed pre- and post-training assessments of attention bias and stress reactivity. As well, EEG was collected during pre- and post-test assessment of attention bias using the dot-probe task. RESULTS Training induced significant changes in attention bias, though findings were complicated by group differences in baseline threat-bias scores. Compared to controls, those in the training group showed greater depression vulnerability to a post-training stressor and increased P2 amplitude, an ERP component associated with attention toward threat, during the dot-probe task. LIMITATIONS Although participants were randomly assigned to groups, there were still group differences in pre-training bias scores. Also, while the use of a stress task before the initial assessment of attention bias was used to control for initial differences in stress vulnerability, this may have altered pre-bias scores since participants completed this task immediately after being stressed. CONCLUSIONS These findings demonstrate training-induced changes in behavior and neural response patterns relevant to work on attention bias modification.

Normalization of EEG activity among previously institutionalized children placed into foster care: A 12-year follow-up of the Bucharest Early Intervention Project

Highlights • Reports EEG activity from 12-year wave of the Bucharest Early Intervention Project.• Intervention effects in neural activity persist from 8-year wave to 12-year wave.• Foster care children have greater alpha power compared to care-as-usual children.• Stable foster care placement showed greater beta power versus disrupted placements.