Right frontal brain activity, cortisol, and withdrawal behavior in 6-month-old infants

Prenatal tobacco and tobacco-Cannabis co-exposure and unpredictability in maternal anger/hostility: Implications for toddler reactivity

Tobacco and cannabis are frequently used together during pregnancy. However, relatively little is known about how co-use and related maternal risk factors impact toddler reactivity. One understudied risk factor is maternal experience of anger/hostility, despite evidence suggesting that individuals who use substances experience more anger/hostility. In addition, mood unpredictability in anger/hostility (MUA), a relatively novel construct, may be particularly important for mothers who use substances as they attempt to cut down or quit during pregnancy and may also impact toddler reactivity. Importantly, prenatal exposures may also impact toddler outcomes via continued postnatal exposure and infant reactivity. We examined a conceptual model linking prenatal tobacco and tobacco-cannabis co-use, maternal anger/hostility, and unpredictability in anger/hostility with toddler reactivity in a sample (N = 247 at recruitment, 190 at toddler age; N = 247 for model testing) of dyads recruited during the first trimester of pregnancy into a tobacco group (use of combustible cigarettes; including sub-group of women who also used cannabis) and a non-substance use group. Results indicated a direct effect of prenatal co-exposure on blunted toddler reactivity for males only. Mothers who used substances prenatally had the highest levels of anger/hostility and MUA. Prenatal anger/hostility and MUA were associated with higher reactivity at infancy which in turn, was associated with higher toddler reactivity. Prenatal co-exposure and higher prenatal maternal anger/hostility was associated with continued postnatal exposure to cannabis which in turn, was associated with higher reactivity at toddlerhood. Results highlight the importance of examining prenatal co-exposure and continued postnatal cannabis exposure as well as associated maternal risk factors such as anger/hostility and MUA for toddler developmental outcomes.

Feasibility and acceptability of using the Alarm Distress BaBy (ADBB) scale within universal health visiting practice in England: a mixed-methods study protocol

INTRODUCTION

The Alarm Distress BaBy (ADBB) scale developed by Guedeney and Fermanian in 2001, is a validated screening tool designed for use by healthcare practitioners to identify infant social withdrawal. This study will explore the acceptability and feasibility of the use of the full ADBB scale and a modified ADBB (m-ADBB) scale as part of routine health visiting visits in England.

METHODS AND ANALYSIS

A mixed methods sequential exploratory design will be used. Five health visitors will be trained in using the ADBB scale and 20 in the m-ADBB scale, from two National Health Service sites in England. Qualitative semi-structured interviews will be carried out with health visitors after they receive the training and again 2 months after using the scales in routine family health visits. Quantitative data will also be collected from the same participants for a range of items during the study period. The theoretical framework of Normalisation Process Theory will underpin the study, to provide in-depth explanations of the implementation process. Qualitative data will be analysed using thematic analysis. Quantitative data will be analysed using descriptive analysis.

ETHICS AND DISSEMINATION

Ethical approval was granted by the University of Oxford Departmental Research Ethics Committee. Dissemination of results will be via organisational websites, social media platforms, newsletters, professional networks, conferences and journal articles.

Frontal alpha asymmetry in anxious school-aged children during completion of a threat identification task

Asymmetry of EEG alpha power in the frontal lobe has been extensively studied over the past 30 years as a potential marker of emotion and motivational state. However, most studies rely on time consuming manipulations in which participants are placed in anxiety-provoking situations. Relatively fewer studies have examined alpha asymmetry in response to briefly presented emotionally evocative stimuli. If alpha asymmetry can be evoked in those situations, it would open up greater methodological possibilities for examining task-driven changes in neural activation. Seventy-seven children, aged 8-12 years old (36 of whom were high anxious), completed three different threat identification tasks (faces, images, and words) while EEG signal was recorded. Alpha power was segmented and compared across trials in which participants viewed threatening vs. neutral stimuli. Threatening images and faces, but not words, induced lower right vs. left alpha power (greater right asymmetry) that was not present when viewing neutral images or faces. Mixed results are reported for the effect of anxiety symptomatology on asymmetry. In a similar manner to studies of state- and trait-level withdrawal in adults, frontal neural asymmetry can be induced in school-aged children using presentation of brief emotional stimuli.

Infant Negativity Moderates Trajectories of Maternal Emotion Across Pregnancy and the Peripartum Period

Background

Although the effects of maternal behavior on the development of child emotion characteristics is relatively well-established, effects of infant characteristics on maternal emotion development is less well known. This gap in knowledge persists despite repeated calls for including child-to-mother effects in studies of emotion. We tested the theory-based postulate that infant temperamental negativity moderates longitudinal trajectories of mothers' perinatal symptoms of anxiety and depression.

Method

Participants were 92 pregnant community women who enrolled in a longitudinal study of maternal mental health; symptoms of anxiety and depression were assessed during the second and third trimesters of pregnancy and again at infant age 4 months. A multimethod assessment of infants' temperament-based negative reactivity was conducted at infant age 4 months.

Results

Maternal symptoms of anxiety showed smaller postnatal declines when levels of infant negativity were high. Negative reactivity, assessed via maternal report of infant behavior, was related to smaller postnatal declines in maternal anxiety, while infant negative reactivity, at the level of neuroendocrine function, was largely unrelated to longitudinal changes in maternal anxiety symptoms. Infant negativity was related to early levels, but largely unrelated to trajectories of maternal symptoms of depression.

Limitations

Limitations of this work include a relatively small and low-risk sample size, the inability to isolate environmental effects, and a nonexperimental design that precludes causal inference.

Conclusions

Findings suggest that levels of infant negativity are associated with differences in the degree of change in maternal anxiety symptoms across the perinatal period.

Temperamental and Theoretical Contributions to Clinical Psychology

This review considers two themes. The first section describes the influence of two temperamental biases detectable in infants that render children vulnerable to maladaptive behavior if the rearing environment invites such responses. Infants who display high levels of limb activity and crying in response to unexpected events are likely to be shy and fearful as children and are at risk for an anxiety disorder. Infants who display little limb movement and crying are susceptible to assuming risks and vulnerable to asocial behavior if the rearing environment invites these actions. The second section criticizes three common research practices: failure to examine patterns of measures for predictors and outcomes, an indifference to the power of the setting on the evidence recorded, and the distortions that semantic terms in questionnaires impose on replies.

Infants' neural responses to helping and hindering scenarios

A growing literature suggests infants prefer prosocial others over antisocial others. Although recent studies have begun to explore the neural mechanisms underlying these responses (Cowell and Decety, 2015; Gredebäck et al., 2015), these studies were based on relatively small samples and focused on distinct aspects of sociomoral responding. The current preregistered study systematically examined infants' neural responses both to prosocial/antisocial interactions and to prosocial/antisocial characters, using larger samples and two distinct age groups. We found that 6- (but not 12-) month-olds showed higher relative right frontal alpha power (indexing approach motivation) when viewing helping versus hindering scenarios. Consistent with past EEG work, infants showed no group-level manual preferences for the helper. However, analyses of infants' neural responses toward images of the helper versus hinderer revealed that both 6- and 12-month-olds showed differential event-related potential (ERP) responses in the P400 and N290 components (indexing social perception) but not in the Nc component (indexing attentional allocation), suggestive that infants' neural responses to prosocial versus antisocial characters reflect social processing. Together, these findings provide a more comprehensive account of infants' responses to prosocial/antisocial interactions and characters, and support the hypothesis that both motivational and socially relevant processes are implicated in infants' sociomoral responding.

Individual differences in social attachment: A multi-disciplinary perspective

Social behavior varies across both individuals and species. Research to explain this variation falls under the purview of multiple disciplines, each with its own theoretical and empirical traditions. Integration of these disciplinary traditions is key to developing a holistic perspective. Here, we review research on the biology of social attachment, a phenomena in which individuals develop strong affective connections to one another. We provide a historical overview of research on social attachment from psychological, ethological and neurobiological perspectives. As a case study, we describe work on pair-bonding in prairie voles, a socially monogamous rodent. This specific topic takes advantage of many biological perspectives and techniques to explain social bonds. Lastly, we conclude with an overview of multi-dimensional conceptual frameworks that can be used to explain social phenomena, and we propose a new framework for research on individual variation in attachment behavior. These conceptual frameworks originate from philosophy, physics, ethology, cognitive science and neuroscience. The application and synthesis of such frameworks offers a rich opportunity to advance understanding of social behavior and its mechanisms.

Differential beta desynchronisation responses to dynamic emotional facial expressions are attenuated in higher trait anxiety and autism

Daily life demands that we differentiate between a multitude of emotional facial expressions (EFEs). The mirror neuron system (MNS) is becoming increasingly implicated as a neural network involved with understanding emotional body expressions. However, the specificity of the MNS's involvement in emotion recognition has remained largely unexplored. This study investigated whether six basic dynamic EFEs (anger, disgust, fear, happiness, sadness, and surprise) would be differentiated through event-related desynchronisation (ERD) of sensorimotor alpha and beta oscillatory activity, which indexes sensorimotor MNS activity. We found that beta ERD differentiated happy, fearful, and sad dynamic EFEs at the central region of interest, but not at occipital regions. Happy EFEs elicited significantly greater central beta ERD relative to fearful and sad EFEs within 800 - 2,000 ms after EFE onset. These differences were source-localised to the primary somatosensory cortex, which suggests they are likely to reflect differential sensorimotor simulation rather than differential attentional engagement. Furthermore, individuals with higher trait anxiety showed less beta ERD differentiation between happy and sad faces. Similarly, individuals with higher trait autism showed less beta ERD differentiation between happy and fearful faces. These findings suggest that the differential simulation of specific affective states is attenuated in individuals with higher trait anxiety and autism. In summary, the MNS appears to support the skills needed for emotion processing in daily life, which may be influenced by certain individual differences. This provides novel evidence for the notion that simulation-based emotional skills may underlie the emotional difficulties that accompany affective disorders, such as anxiety.

Developmental variation in testosterone:cortisol ratio alters cortical- and amygdala-based cognitive processes

Testosterone (T) and cortisol (C) are the end products of neuroendocrine axes that interact with the process of shaping brain structure and function. Relative levels of T:C (TC ratio) may alter prefrontal-amygdala functional connectivity in adulthood. What remains unclear is whether TC-related effects are rooted to childhood and adolescence. We used a healthy cohort of 4-22-year-olds to test for associations between TC ratios, brain structure (amygdala volume, cortical thickness (CTh), and their coordinated growth), as well as cognitive and behavioral development. We found greater TC ratios to be associated with the growth of specific brain structures: 1) parietal CTh; 2) covariance of the amygdala with CTh in visual and somatosensory areas. These brain parameters were in turn associated with lower verbal/executive function and higher spatial working memory. In sum, individual TC profiles may confer a particular brain phenotype and set of cognitive strengths and vulnerabilities, prior to adulthood.

Alpha frontal asymmetry underlies individual differences in reactivity to acute psychosocial stress in males

People vary in their responses to stress. The present study aimed to investigate whether and how alpha frontal asymmetry (AFA) measured in the resting state underlies the individual differences in psychological responses to acute psychosocial stress (e.g., increases in heart rate and cortisol) induced by the Trier social stress test. Forty-three healthy male adults were enrolled in this study. The results showed that the AFA score negatively predicted both heart rate and cortisol responses, that is relatively higher right-frontal activity during the resting state was related to a stronger physiological stress response. These results indicated that higher withdrawal motivation or effortful control is associated with a higher physiological stress response, which suggested that AFA in the resting state can serve as a biological predictor of acute stress responses in men.

Stress-induced plasma cortisol concentrations in infancy are associated with later parenting behaviors in female rhesus macaques (Macaca mulatta)

Few studies have longitudinally assessed the relationship between infant stress reactivity and future parenting style. Studies show that stress-induced plasma cortisol concentrations are stable over development and that they can be utilized as a marker for stress reactivity. This study investigates the relationship between stress-induced plasma cortisol concentrations in infancy and later parenting behavior in a translational nonhuman primate model. We hypothesized that higher stress-induced cortisol levels in infancy would predict impairments in maternal behaviors in adulthood. Subjects were rhesus macaque females (N = 122; Macaca mulatta), assessed as infants and again as mothers. At 3-4 months of age, subjects underwent a standardized BioBehavioral Assessment during which blood samples were obtained and they were assessed for behaviorally inhibition. Approximately 7 years later, subjects were observed as they interacted with their own offspring for four 300-s sessions. Typical rhesus monkey mother-offspring behaviors were recorded, including approaches and leaves and maternal cradling. Results showed that subjects' stress-induced cortisol concentrations and whether they exhibited behavioral inhibition as infants predicted later maternal behavior, with high cortisol concentrations and behavioral inhibition predicting high rates of offspring approaches and leaves and low rates of maternal cradling. Results also showed that higher stress-induced cortisol concentrations in infancy predicted higher scores on the Brown Index, an indication that the subjects' offspring, rather than the subject themselves, initiated changes in proximity. Taken together, these results suggest that individuals that exhibit higher stress-induced cortisol concentrations and behavioral inhibition at 3-4 months of age are at risk for engaging in less sensitive parenting behaviors as adults. To the extent that these findings generalize to humans, they suggest an important link between stress-induced cortisol concentrations and behavioral inhibition in infancy and behavior later in life, such that early-life stress reactivity can serve as a marker for later parenting behavior.

Development and validation of the Mindful Parenting in Infancy Scale (MPIS)

Although mindfulness in parenting has been recognized as important for some time, there is a dearth of measurement tools, especially for caregivers of infants. Two studies were conducted: (1) developing and providing an initial psychometric evaluation of the Mindful Parenting in Infancy Scale (MPIS) and (2) reproducing initial findings with an independent sample of infants and caregivers. In Study 1, 37 caregivers of infants (3-12 months of age) responded to MPIS, providing indicators of parenting stress and infant temperament. Study 2 caregivers (N = 57) responded to identical measures, with infant electroencephalogram (EEG) recorded during the Still Face Procedure, along with a baseline condition. Study 1 results indicated good internal consistency, with Study 2 providing additional support for reliability. Correlations with parenting stress markers were also significant across both investigations, indicative of greater stress with lower levels of mindfulness. A number of correlations with temperament scores were also significant, and in the hypothesized direction, across both studies. Importantly, the MPIS score was predictive of infant frontal EEG asymmetry in a path model examined in the context of Study 2. Thus, the present investigation provides support for MPIS as a promising brief measurement tool based on results obtained with two independent samples.

Nonhuman Primate Models to Explore Mechanisms Underlying Early-Life Temperamental Anxiety

Anxiety disorders are among the most prevalent psychiatric disorders, causing significant suffering and disability. Behavioral inhibition is a temperament that is linked to an increased risk for the later development of anxiety disorders and other stress-related psychopathology, and understanding the neural systems underlying this dispositional risk could provide insight into novel treatment targets for anxiety disorders. Nonhuman primates (NHPs) have anxiety-related temperaments that are similar to those of humans with behavioral inhibition, facilitating the design of translational models related to human psychopathology. Characterization of our NHP model of behavioral inhibition, which we term anxious temperament (AT), reveals that it is trait-like. Exploration of the neural substrates of AT in NHPs has revealed a distributed neural circuit that is linked to individual differences in AT, which includes the dorsal amygdala. AT-related metabolism in the dorsal amygdala, including the central nucleus, is stable across time and can be detected even in safe contexts, suggesting that AT has trait-like neural signatures within the brain. The use of lesioning and novel chemogenetic methods allows for mechanistic perturbation of the amygdala to determine its causal contribution to AT. Studies characterizing the molecular bases for individual differences in AT in the dorsal amygdala, which take advantage of novel methods for probing cellular and molecular systems, suggest involvement of neurotrophic systems, which point to the importance of neuroplasticity in AT. These novel methods, when used in combination with translational NHP models such as AT, promise to provide insights into the brain systems underlying the early risk for anxiety disorder development.

Affectionate Touch in the Context of Breastfeeding and Maternal Depression Influences Infant Neurodevelopmental and Temperamental Substrates

BACKGROUND

While numerous studies have demonstrated maternal depression's influence on infant brain development, few studies have examined the changes that occur as a consequence of co-occurring experiential factors that affect quality of mother and infant affectionate touch as well as infant temperament and neurophysiological systems. The aim of the study was to examine the interactive effects of maternal depression and breastfeeding on mother and infant affectionate touch and infant temperament and cortical maturation patterns across early development.

METHODS

113 mothers and their infants participated when infants were 1 and 3 months of age. Questionnaires to assess maternal depressive symptoms, feeding, and temperament were completed. Tonic EEG patterns (asymmetry and left and right activity) were collected and the dyads were video-recorded during feeding to assess mother and infant affectionate touch patterns.

RESULTS

Data analysis showed that EEG activity and mother-infant affectionate touch differed as a function of mood and feeding method. Notably, only infants of depressed mothers that bottle-fed showed right frontal EEG asymmetry and attenuated change in the left frontal region across 3 months. Breastfeeding positively impacted affectionate touch behaviors and was associated with increased left and decreased right frontal EEG activation even for depressed groups. Furthermore, a model incorporating physiology, maternal depression, touch, temperament, and feeding indicated significant prediction for infant affectionate touch (with breastfeeding and affectively positive temperament demonstrating the strongest prediction). Con-clusion: The findings suggest that breastfeeding and the infant's positive temperament influence mother-infant affectionate touch patterns and result in neuroprotective outcomes for infants, even those exposed to maternal depression within early development.

Frontal Asymmetry in an approach-avoidance conflict paradigm

The frontal cortex appears to be asymmetrically related to approach motivation, avoidance motivation, and motivational conflict. Much past work has investigated approach and avoidance motivation, but little work has investigated frontal asymmetry in the face of motivational conflict in part because of the inherent conflict between avoidance motivation and motivational conflict. The current study sought to disentangle the existing confound between avoidance motivation and motivational conflict. In the study, participants selected the likelihood of viewing negative (vs. positive) images for zero reward points (avoidance only condition), or negative (vs. positive) images for the chance to win reward points (approach-avoidance conflict conditions). Participants exhibited greater relative right frontal asymmetry while making percent likelihood selections in the approach-avoidance conflict conditions relative to the avoidance only conditions. Additionally, participants exhibited greater relative right frontal asymmetry while viewing disgust images during trials with the greatest approach-avoidance conflict relative to trials with the lowest approach-avoidance conflict. Together, these results suggest that motivational conflict, and not avoidance motivation, is associated with greater relative right frontal activity.

Consistency of EEG asymmetry patterns in infants of depressed mothers

We evaluated frontal electroencephalogram (EEG) asymmetry across multiple contexts as an index of a general affective response predisposition in 12-month-old infants whose mothers were at elevated risk for perinatal depression due to their mother's history of depression. We further examined mothers' prenatal, postnatal, and concurrent depressive symptom levels in relation to infants' frontal EEG asymmetry consistency. Mothers (n = 132) with a history of depression prior to pregnancy completed depressive symptom scales repeatedly during pregnancy and the first year postpartum. Their 12-month-old infants' frontal EEG asymmetry was recorded across five contexts (baseline/bubbles, peek-a-boo, play, feeding, and distract). Frontal EEG asymmetries showed small to moderate correlations across contexts. Mothers' prenatal depression symptom levels (not postnatal or concurrent) were associated with infants having consistent right, rather than left, frontal EEG asymmetry, even after controlling for infants' observed affect. These findings demonstrate the consistency of EEG asymmetry scores across contexts in 12-month-old infants at risk for the development of psychopathology, providing support for relative right frontal EEG asymmetry as a trait marker of vulnerability to depression. Findings also suggest the importance of mothers' prenatal, rather than postnatal or concurrent depression, in predicting infants' consistent patterns of relative right frontal EEG asymmetry across contexts.

Child Temperament and Total Diurnal Cortisol in Out-of-Home Center-Based Child Care and in At-Home Parental Care

The association between child temperament characteristics and total diurnal saliva cortisol in 84 children (M = 2.3 years, SD = 0.6) attending out‐of‐home, center‐based child care and 79 children (M = 2.0 years, SD = 0.5) attending at‐home parental care was examined. Saliva samples were collected during two consecutive days, that is, Sunday and Monday, with four samples taken per day. While children higher in surgency had higher total diurnal cortisol production, we did not find evidence that temperament moderated the associations between child‐care context and total diurnal cortisol. Negative affectivity and effortful control were not related to cortisol output. Our findings suggest that temperamental surgency may be associated with higher total cortisol production in early childhood across child‐care settings.

Impact of maternal childhood trauma on child behavioral problems: The role of child frontal alpha asymmetry

Childhood trauma is associated with many long-term negative outcomes, and is not limited to the individual experiencing the trauma, but extends to subsequent generations. However, mechanisms underlying the association between maternal childhood trauma and child psychopathology are not well understood. Here, we targeted frontal alpha asymmetry (FAA) as a potential underlying factor of the relationship between maternal childhood trauma and child behavioral problems. Electroencephalography (EEG) was recorded from (N = 45) children (Mean age = 57.9 months, SD = 3.13) during an eyes-closed paradigm in order to evaluate FAA. Mothers reported on their childhood trauma experiences using the Childhood Trauma Questionnaire (CTQ), and on their child's behavior using the child behavior checklist (CBCL). We found that maternal childhood trauma significantly predicted child total, internalizing, and externalizing behavior at age 5 years. We also observed a role for FAA such that it acted as a moderator, but not mediator, for behavioral problems. We found that children with relative more right/less left frontal activity were more at risk to develop behavioral problems when their mother had been exposed to trauma in her childhood. These results indicate that child frontal asymmetry may serve as a susceptibility marker for child behavioral problems.

Modeling development of frontal electroencephalogram (EEG) asymmetry: Sex differences and links with temperament

Asymmetric patterns of frontal brain electrical activity reflect approach and avoidance tendencies, with stability of relative right activation associated with withdrawal emotions/motivation and left hemisphere activation linked with approach and positive affect. However, considerable shifts in approach/avoidance-related lateralization have been reported for children not targeted because of extreme temperament. In this study, dynamic effects of frontal electroencephalogram (EEG) power within and across hemispheres were examined throughout early childhood. Specifically, EEG indicators at 5, 10, 24, 36, 48, and 72 months-of-age (n = 410) were analyzed via a hybrid of difference score and panel design models, with baseline measures and subsequent time-to-time differences modeled as potentially influencing all subsequent amounts of time-to-time change (i.e., predictively saturated). Infant sex was considered as a moderator of dynamic developmental effects, with temperament attributes measured at 5 months examined as predictors of EEG hemisphere development. Overall, change in left and right frontal EEG power predicted declining subsequent change in the same hemisphere, with effects on the opposing neurobehavioral system enhancing later growth. Infant sex moderated the pattern of within and across-hemisphere effects, wherein for girls more prominent left hemisphere influences on the right hemisphere EEG changes were noted and right hemisphere effects were more salient for boys. Largely similar patterns of temperament prediction were observed for the left and the right EEG power changes, with limited sex differences in links between temperament and growth parameters. Results were interpreted in the context of comparable analyses using parietal power values, which provided evidence for unique frontal effects.

Infant frontal EEG asymmetry moderates the association between maternal behavior and toddler negative affectivity

Relatively little work has examined potential interactions between child intrinsic factors and extrinsic environmental factors in the development of negative affect in early life. This work is important because high levels of early negative affectivity have been associated with difficulties in later childhood adjustment. We examined associations between infant frontal electroencephalogram (EEG), maternal parenting behaviors, and children's negative affect across the first two years of life. Infant baseline frontal EEG asymmetry was measured at 5 months; maternal sensitivity and intrusiveness were observed during mother-child interaction at 5 and 24 months; and mothers provided reports of toddler negative affect at 24 months. Results indicated that maternal sensitive behaviors at 5 months were associated with less negative affect at 24 months, but only for infants with left frontal EEG asymmetry. Similarly, maternal sensitive behaviors at 24 months were associated with less toddler negative affect at 24 months, but only for infants with left frontal EEG asymmetry. In contrast, maternal intrusive behaviors at 5- and 24-months were associated with greater toddler negative affect, but only for infants with right frontal EEG asymmetry at 5-months. Findings suggest that levels of negative affect in toddlers may be at least partially a result of interactions between children's own early neurophysiological functioning and maternal behavior during everyday interactions with children in the first two years of life.

Stress, aggression, and the balance of approach and avoidance

Stress is a well-established risk factor for many mental disorders including anxiety disorders or substance abuse. A hallmark of these disorders is an imbalance between behavioral approach and avoidance in situations with approach-avoidance conflicts and unclear outcomes. However, if and how stress affects human behavior in approach-avoidance conflicts is largely unknown. To investigate the effects of stress on approach-avoidance behavior, 80 participants underwent a stress or control manipulation before performing an approach-avoidance conflict task. Stress markedly increased behavioral inhibition when threats were distant and accelerated responses when threats were close; suggesting that stress amplifies the importance of threat distance. However, participants high in trait aggression showed increased approach behavior, particularly when stressed. These findings indicate that stress generally leads to enhanced avoidance, but induces approach in individuals prone to aggression, with important implications for stress-related psychopathologies.

Maternal sensitivity during the first 3½ years of life predicts electrophysiological responding to and cognitive appraisals of infant crying at midlife

This study examined the predictive significance of maternal sensitivity in early childhood for electrophysiological responding to and cognitive appraisals of infant crying at midlife in a sample of 73 adults (age = 39 years; 43 females; 58 parents) from the Minnesota Longitudinal Study of Risk and Adaptation. When listening to an infant crying, both parents and nonparents who had experienced higher levels of maternal sensitivity in early childhood (between 3 and 42 months of age) exhibited larger changes from rest toward greater relative left (vs. right) frontal EEG activation, reflecting an approach-oriented response to distress. Parents who had experienced greater maternal sensitivity in early childhood also made fewer negative causal attributions about the infant's crying; the association between sensitivity and attributions for infant crying was nonsignificant for nonparents. The current findings demonstrate that experiencing maternal sensitivity during the first 3½ years of life has long-term predictive significance for adults' processing of infant distress signals more than three decades later. (PsycINFO Database Record

The theta burst transcranial magnetic stimulation over the right PFC affects electroencephalogram oscillation during emotional processing

Prefrontal cortex (PFC) plays an important role in emotional processing and therefore is one of the most frequently targeted regions for non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS) in clinical trials, especially in the treatment of emotional disorders. As an approach to enhance the effectiveness of rTMS, continuous theta burst stimulation (cTBS) has been demonstrated to be efficient and safe. However, it is unclear how cTBS affects brain processes related to emotion. In particular, psychophysiological studies on the underlying neural mechanisms are sparse. In the current study, we investigated how the cTBS influences emotional processing when applied over the right PFC. Participants performed an emotion recognition Go/NoGo task, which asked them to select a GO response to either happy or fearful faces after the cTBS or after sham stimulation, while 64-channel electroencephalogram (EEG) was recorded. EEG oscillation was examined using event-related spectral perturbation (ERSP) in a time-interval between 170 and 310ms after face stimuli onset. In the sham group, we found a significant difference in the alpha band between response to happy and fearful stimuli but that effect did not exist in the cTBS group. The alpha band activity at the scalp was reduced suggesting the excitatory effect at the brain level. The beta and gamma band activity was not sensitive to cTBS intervention. The results of the current study demonstrate that cTBS does affect emotion processing and the effect is reflected in changes in EEG oscillations in the alpha band specifically. The results confirm the role of prefrontal cortex in emotion processing. We also suggest that this pattern of cTBS results elucidates mechanisms by which mood improvement in depressive disorders is achieved using cTBS intervention.

Neurophysiological markers of high anxiety level in man during the process of preparing for a visual recognition

By means of EEG analysis the functional state of subjects with high and low levels of anxiety was studied in different periods preceding a cognitive task - a visual expression recognition. Several conditions were investigated: background/eyes closed; background/eyes opened; listening the instruction for the cognitive task; operative rest (time lapse between listening the instruction and the beginning of the task), as well as short intervals immediately preceding the exposition of target stimuli (stage of preparation) - pairs of faces pictures with identical or different emotional expressions. At all these pre-task stages high-anxiety subjects exhibited much lower amplitude values in alpha and theta bands (as compared with low-anxiety subjects). The most prominent differences were revealed in the phases of instruction listening and operative rest. These data could provide more precise electrophysiological markers of anxiety level in conditions preceeding cognitive task performance.

Short- and long-term stability of alpha asymmetry in infants: Baseline and affective measures

Asymmetry in cortical activity was tested for short- and long-term stability during the first year of life. Infants (N = 129) completed a total of four laboratory visits: two visits occurred about 1 week apart when infants were 6 months old, and two visits occurred about 1 week apart when infants were 12 months of age. At each laboratory visit, EEG readings were taken during five 1-min, neutral baselines as well as during a negative and a positive emotion-eliciting task. The stability of hemispheric asymmetry was assessed at midfrontal (F3/4, F7/8) and parietal (P3/4) electrode sites. Asymmetry in baseline and fear-eliciting episodes showed moderate short-term stability. Long-term stability was apparent when assessments were composited at 6 months and 12 months. Frontal asymmetry was greater than parietal asymmetry for baseline recordings. There was minimal evidence for stability in asymmetry during positive emotion tasks. Results are discussed with regard to the collection and interpretation of alpha asymmetry measures during infancy.

Intraindividual and Interindividual Differences in Spontaneous Eye Blinking: Relationships to Working Memory Performance and Frontal EEG Asymmetry

The rate and timing of spontaneous eye blinking (SB) may be used to explore mechanisms of cognitive activity in infancy. In particular, SB rate is believed to reflect some dimensions of dopamine function; therefore, we hypothesized that SB rate would relate to working memory performance and to frontal electroencephalogram (EEG) asymmetry. Forty, 10-mo-old infants completed an A-not-B task while SB and EEG were measured throughout. We found that SB rate varied across phases of the task, variability in SB rate was positively related to working memory performance, and frontal EEG asymmetry was related to individual differences in the rate of SB. Results provide indirect, but convergent support for the hypothesis that SB rate reflects dopamine function early in human development. As such, these results have implications for understanding the tonic and phasic effects of dopamine on cognitive activity early in human development.

Infant EEG and temperament negative affectivity: Coherence of vulnerabilities to mothers' perinatal depression

Associations between infants' frontal EEG asymmetry and temperamental negative affectivity (NA) across infants' first year of life and the potential moderating role of maternal prenatal depressive symptoms were examined prospectively in infants (n = 242) of mothers at elevated risk for perinatal depression. In predicting EEG, in the context of high prenatal depressive symptoms, infant NA and frontal EEG asymmetry were negatively associated at 3 months of age and positively associated by 12 months of age. By contrast, for low depression mothers, infant NA and EEG were not significantly associated at any age. Postnatal depressive symptoms did not add significantly to the models. Dose of infants' exposure to maternal depression mattered: infants exposed either pre- or postnatally shifted from a positive association at 3 months to a negative association at 12 months; those exposed both pre- and postnatally shifted from a negative association at 3 months to a positive association at 12 months. Prenatal relative to postnatal exposure did not matter for patterns of association between NA and EEG. The findings highlight the importance of exploring how vulnerabilities at two levels of analysis, behavioral and psychophysiological, co-occur over the course of infancy and in the context of mothers' depressive symptomatology.

Deficit in rewarding mechanisms and prefrontal left/right cortical effect in vulnerability for internet addiction

OBJECTIVE

The present research explored the cortical correlates of rewarding mechanisms and cortical 'unbalance' effect in internet addiction (IA) vulnerability.

METHODS

Internet Addiction Inventory (IAT) and personality trait (Behavioural Inhibition System, BIS; Behavioural Activation System, BAS) were applied to 28 subjects. Electroencephalographic (EEG, alpha frequency band) and response times (RTs) were registered during a Go-NoGo task execution in response to different online stimuli: gambling videos, videogames or neutral stimuli. Higher-IAT (more than 50 score, with moderate or severe internet addiction) and lower-IAT (<50 score, with no internet addiction).

RESULTS

Alpha band and RTs were affected by IAT, with significant bias (reduced RTs) for high-IAT in response to gambling videos and videogames; and by BAS, BAS-Reward subscale (BAS-R), since not only higher-IAT, but also BAS and BAS-R values determined an increasing of left prefrontal cortex (PFC) activity (alpha reduction) in response to videogames and gambling stimuli for both Go and NoGo conditions, in addition to decreased RTs for these stimuli categories.

CONCLUSION

The increased PFC responsiveness and the lateralisation (left PFC hemisphere) effect in NoGo condition was explained on the basis of a 'rewarding bias' towards more rewarding cues and a deficit in inhibitory control in higher-IAT and higher-BAS subjects. In contrast lower-IAT and lower-BAS predicted a decreased PFC response and increased RTs for NoGo (inhibitory mechanism). These results may support the significance of personality (BAS) and IAT measures for explaining future internet addiction behaviour based on this observed 'vulnerability'.

Behavioral and neural correlates of emotional development: typically developing infants and infants of depressed and/or anxious mothers

OBJECTIVES

To describe the main findings of studies of behavioral and neural correlates regarding the development of facial emotion processing during the first year of life in typically developing infants and infants of depressed and/or anxious mothers.

SOURCES

Comprehensive, non-systematic review of the literature on studies about individual differences in facial emotion processing by newborns and infants over the first year of life.

SUMMARY OF THE FINDINGS

Maternal stress related to depression and anxiety has been associated to atypical emotional processing and attentional behaviors in the offspring. Recent neurophysiological studies using electroencephalogram and event-related potentials have begun to shed light on the possible mechanisms underlying such behaviors.

CONCLUSIONS

Infants of depressed and/or anxious mothers have increased risk for several adverse outcomes across the lifespan. Further neurobehavioral investigations and the promotion of clinical and developmental research integration might eventually contribute to refining screening tools, improving treatment, and enabling primary prevention interventions for children at risk.

Frontal Electroencephalogram Asymmetry and Temperament Across Infancy and Early Childhood: An Exploration of Stability and Bidirectional Relations

The stability of frontal electroencephalogram (EEG) asymmetry, temperamental activity level and fear, as well as bidirectional relations between asymmetry and temperament across the first 4 years of life, were examined in a sample of 183 children. Children participated in annual laboratory visits through 48 months, providing EEG and maternal report of temperament. EEG asymmetry showed moderate stability between 10 and 24 months. Analyses revealed that more left asymmetry predicted later activity level across the first 3 years. Conversely, asymmetry did not predict fear. Rather, fear at 36 months predicted more right asymmetry at 48 months. Results highlight the need for additional longitudinal research of infants and children to increase understanding of bidirectional relations between EEG and temperament in typically developing populations.

Early Caregiving and Human Biobehavioral Development: A Comparative Physiology Approach

A large and growing body of evidence demonstrates associations between quality of the early caregiving environment and risk for stress-related illness across the lifespan. The recent research examining associations between early caregiving environments and subsequent development is reviewed, with particular attention to early programming and subsequent malleability of systems underlying stress responsivity. A developmental comparative physiology model is suggested; one in which postnatal programming and phenotypic plasticity act in concert as mechanisms underlying the persisting effects of early care environments for biobehavioral outcomes.

Infant frontal electroencephalogram asymmetry and negative emotional reactivity as predictors of toddlerhood effortful control

Given the importance of children's self-regulation, relations were examined between two fundamental components of self-regulation, specifically temperamentally based reactivity and regulation. Infant negative emotional reactivity and regulation, measured via frontal electroencephalogram (EEG) asymmetry, were examined as potential precursors to understanding toddlerhood regulation, conceptualized as effortful control. Our longitudinal design allowed for examination of two perspectives on the interplay of reactivity and regulation, namely that (a) early negative affectivity interferes with the development of later regulation and (b) regulation is necessary to modulate negative affectivity and, thus, would buffer the effects of negative affectivity on later regulation. Mother-child dyads participated in a three-wave longitudinal study. Baseline frontal EEG asymmetry was assessed at 10months (T1). Mothers rated children's negative reactivity at both 10 and 24months (T2). Children's effortful control, measured at 30-36months (T3), was a composite score of maternal ratings and observed behavior during a snack delay. Negative affectivity was related to effortful control; however, significant interactions between negative affect and frontal EEG asymmetry were found. Higher levels of negative affectivity at both T1 and T2 were associated with lower levels of effortful control at T3, but only for toddlers who also had right frontal EEG asymmetry. Negative affectivity was not associated with effortful control for the left frontal EEG asymmetry group. Our moderation findings highlight the complex relations of negative affect and frontal EEG asymmetry in understanding children's development of self-regulation, specifically effortful control. The interaction between early reactivity and physiological regulation indicates that both may be important precursors of effortful control.

Iron deficiency (ID) at both birth and 9 months predicts right frontal EEG asymmetry in infancy

This study considered effects of timing and duration of iron deficiency (ID) on frontal EEG asymmetry in infancy. In healthy term Chinese infants, EEG was recorded at 9 months in three experimental conditions: baseline, peek-a-boo, and stranger approach. Eighty infants provided data for all conditions. Prenatal ID was defined as low cord ferritin or high ZPP/H. Postnatal ID was defined as ≥ two abnormal iron measures at 9 months. Study groups were pre- and postnatal ID, prenatal ID only, postnatal ID only, and not ID. GLM repeated measure analysis showed a main effect for iron group. The pre- and postnatal ID group had negative asymmetry scores, reflecting right frontal EEG asymmetry (mean ± SE: -.18 ± .07) versus prenatal ID only (.00 ± .04), postnatal ID only (.03 ± .04), and not ID (.02 ± .04). Thus, ID at both birth and 9 months was associated with right frontal EEG asymmetry, a neural correlate of behavioral withdrawal and negative emotions.

Maternal negative affect during infancy is linked to disrupted patterns of diurnal cortisol and alpha asymmetry across contexts during childhood

Maternal negative affect in the early environment is believed to sensitize long-term coping capacities in children. Yet, little work has identified physiological systems associated with coping responses, which may serve as mechanisms for links between early maternal negativity and child outcomes. Using a longitudinal twin sample (N=89), we found that high levels of maternal negative affect during infancy were associated with dysregulation of diurnal cortisol and electroencephalograph (EEG) asymmetry, two physiological systems that may support active approach-oriented coping when children are 7years old. Flattened slopes of diurnal cortisol were also associated with greater numbers of concurrent overanxious behaviors in children. A mediation analysis supported the role of dysregulated diurnal cortisol as a mediator of the link between maternal negative affect in the early environment and childhood risk for anxiety problems.

Left Hemispheric Imbalance and Reward Mechanisms Affect Gambling Behavior: The Contribution of the Metacognition and Cortical Brain Oscillations

The present research used the Iowa Gambling Task to test the effect of the reward-sensitivity Behavioral Activation System-Reward (BAS-Reward) construct on the ability to distinguish between high- and low-risk decisions. To elucidate the individual differences that influence the decisional processes, making the strategies more or less advantageous, we considered the impact of the BAS motivational system and the frontal left and right cortical activity on subjects' decisions. More specifically, the lateralization effect, which is related to the increased activation of the left (BAS-Reward-related) hemisphere, was explored by using frequency band analysis. Specifically, behavioral responses (gain/loss options), metacognition, and delta, theta, alpha, and beta band modulation (asymmetry index) were considered. Thirty subjects were divided into high-BAS and low-BAS groups. In comparison with low-BAS, the high-BAS group showed an increased tendency to opt in favor of the immediate reward (losing strategy) instead of the long-term option (winning strategy), and members of this group were more impaired in metacognitive monitoring of their strategies and showed an increased left hemisphere activation when they responded to losing choices. A "reward bias" effect was hypothesized to act for high BAS, based on a left-hemisphere hyperactivation.

The role of frontal EEG asymmetry in post-traumatic stress disorder

Frontal alpha asymmetry, a biomarker derived from electroencephalography (EEG) recordings, has often been associated with psychological adjustment, with more left-sided frontal activity predicting approach motivation and lower levels of depression and anxiety. This suggests high relevance to post-traumatic stress disorder (PTSD), a disorder comprising anxiety and dysphoria symptoms. We review this relationship and show that frontal asymmetry can be plausibly linked to neuropsychological abnormalities seen in PTSD. However, surprisingly few studies (k = 8) have directly addressed frontal asymmetry in PTSD, mostly reporting that trait frontal asymmetry has little (if any) predictive value. Meanwhile, preliminary evidence suggest that state-dependent asymmetry during trauma-relevant stimulation distinguishes PTSD patients from resilient individuals. Thus, exploring links between provocation-induced EEG asymmetry and PTSD appears particularly promising. Additionally, we recommend more fine-grained analyses into PTSD symptom clusters in relation to frontal asymmetry. Finally, we highlight hypotheses that may guide future research and help to fully apprehend the practical and theoretical relevance of this biological marker.

Attachment classification, psychophysiology and frontal EEG asymmetry across the lifespan: a review

In recent years research on physiological response and frontal electroencephalographic (EEG) asymmetry in different patterns of infant and adult attachment has increased. We review research findings regarding associations between attachment classifications and frontal EEG asymmetry, the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenocortical axis (HPA). Studies indicate that insecure attachment is related to a heightened adrenocortical activity, heart rate and skin conductance in response to stress, which is consistent with the hypothesis that attachment insecurity leads to impaired emotion regulation. Research on frontal EEG asymmetry also shows a clear difference in the emotional arousal between the attachment groups evidenced by specific frontal asymmetry changes. Furthermore, we discuss neurophysiological evidence of attachment organization and present up-to-date findings of EEG-research with adults. Based on the overall patterns of results presented in this article we identify some major areas of interest and directions for future research.

Decisional impairments in cocaine addiction, reward bias, and cortical oscillation "unbalance"

A vast amount of research has suggested that subjects with substance use disorder (SUD) might have difficulty making advantageous decisions that opt in favor of a longer-term, larger reward than an immediate, smaller reward. The current research explored the impact of reward bias and cortical frontal asymmetry (left lateralization effect) in SUD in response to a decisional task (Iowa Gambling Task). Fifty SUD participants and 40 controls (CG) were tested using the Iowa Gambling Task. Electrophysiology (electroencephalography) recording was performed during task execution. We measured left and right dorsolateral prefrontal cortex power activity. Behavioral responses (gain/loss options); frequency band modulation (asymmetry index) for delta, theta, alpha, and beta band; and cortical source localization (standardized low-resolution brain electromagnetic tomography) were considered. The SUD group opted in favor of the immediate reward option (loss) more frequently than the long-term option (gain) when compared to the CG. Secondly, SUD showed increased left-hemisphere activation in response to losing (with immediate reward) choices in comparison with the CG. The left hemispheric unbalance effect and the "reward bias" were adduced to explain the decisional impairment in SUD.