Atypical EEG power correlates with indiscriminately friendly behavior in internationally adopted children

While effects of institutional care on behavioral development have been studied extensively, effects on neural systems underlying these socioemotional and attention deficits are only beginning to be examined. The current study assessed electroencephalogram (EEG) power in 18-month-old internationally adopted, postinstitutionalized children (n = 37) and comparison groups of nonadopted children (n = 47) and children internationally adopted from foster care (n = 39). For their age, postinstitutionalized children had an atypical EEG power distribution, with relative power concentrated in lower frequency bands compared with nonadopted children. Both internationally adopted groups had lower absolute alpha power than nonadopted children. EEG power was not related to growth at adoption or to global cognitive ability. Atypical EEG power distribution at 18 months predicted indiscriminate friendliness and poorer inhibitory control at 36 months. Both postinstitutionalized and foster care children were more likely than nonadopted children to exhibit indiscriminate friendliness. Results are consistent with a cortical hypoactivation model of the effects of early deprivation on neural development and provide initial evidence associating this atypical EEG pattern with indiscriminate friendliness. Outcomes observed in the foster care children raise questions about the specificity of institutional rearing as a risk factor and emphasize the need for broader consideration of the effects of early deprivation and disruptions in care.     

Effects of foster care intervention and caregiving quality on the bidirectional development of executive functions and social skills following institutional rearing

Institutional rearing negatively impacts the development of children's social skills and executive functions (EF). However, little is known about whether childhood social skills mediate the effects of the foster care intervention (FCG) and foster caregiving quality following early institutional rearing on EF and social skills in adolescence. We examined (a) whether children's social skills at 8 years mediate the impact of the FCG on the development of EF at ages 12 and 16 years, and (b) whether social skills and EF at ages 8 and 12 mediate the relation between caregiving quality in foster care at 42 months and subsequent social skills and EF at age 16. Participants included abandoned children from Romanian institutions, who were randomly assigned to a FCG (n = 68) or care as usual (n = 68), and a never-institutionalized group (n = 135). At ages 8, 12, and 16, social skills were assessed via caregiver and teacher reports and EF were assessed via the Cambridge Neuropsychological Test Automated Battery. Caregiving quality of foster caregivers was observed at 42 months. FCG predicted better social skills at 8 years, which in turn predicted better EF in adolescence. Higher caregiver quality in foster care at 42 months predicted better social skills at 8 and 12 years, and better EF at 12 years, which in turn predicted 16-year EF and social skills. These findings suggest that interventions targeting caregiving quality within foster care home environments may have long-lasting positive effects on children's social skills and EF.     

Imagery-induced negative affect,social touch and frontal EEG power band activity

Social touch seems to modulate emotions, but its brain correlates are poorly understood. Here, we investigated if frontal power band activity in the electroencephalogram (EEG) during aversive mental imagery is modulated by social touch from one’s romantic partner and a stranger. We observed the highest theta and beta power when imaging alone, next so when being touched by a stranger, with lowest theta and beta activity during holding hands with the loved one. Delta power was higher when being alone than with a stranger or a partner, with no difference between the two. Gamma power was highest during the stranger condition and lower both when being alone and with the partner, while alpha power did not change as a function of social touch. Theta power displayed a positive correlation with electrodermal activity supporting its relation to emotional arousal. Attachment style modulated the effect of touch on the EEG as only secure but not insecure partner bonding was associated with theta power reductions. Because theta power was sensitive to the experimental perturbations, mapped onto peripheral physiological arousal and reflected partner attachment style we suggest that frontal theta power might serve as an EEG derived bio-marker for social touch in emotionally significant dyads.     

Event‐related oscillations (EROs) and event‐related potentials (ERPs) comparison in facial expression recognition

The study aims to explore the significance of event‐related potentials (ERPs) and event‐related brain oscillations (EROs) (delta, theta, alpha, beta, gamma power) in response to emotional (fear, happiness, sadness) when compared with neutral faces during 180–250 post‐stimulus time interval. The ERP results demonstrated that the emotional face elicited a negative peak at approximately 230 ms (N2). Moreover, EEG measures showed that motivational significance of face (emotional vs. neutral) could modulate the amplitude of EROs, but only for some frequency bands (i.e. theta and gamma bands). In a second phase, we considered the resemblance of the two EEG measures by a regression analysis. It revealed that theta and gamma oscillations mainly effect as oscillation activity at the N2 latency. Finally, a posterior increased power of theta was found for emotional faces.     

Longitudinal study of perception of structured optic flow and random visual motion in infants using high‐density EEG

Electroencephalogram (EEG) was used in infants at 3–4 months and 11–12 months to longitudinally study brain electrical activity as the infants were exposed to structured forwards and reversed optic flow, and non‐structured random visual motion. Analyses of visual evoked potential (VEP) and temporal spectral evolution (TSE, time‐dependent amplitude changes) were performed on EEG data recorded with a 128‐channel sensor array. VEP results showed infants to significantly differentiate between the radial motion conditions, but only at 11–12 months where they showed shortest latency for forwards optic flow and longest latency for random visual motion. When the TSE results of the motion conditions were compared with those of a static non‐flow dot pattern, infants at 3–4 and 11–12 months both showed significant differences in induced activity. A decrease in amplitudes at 5–7 Hz was observed as desynchronized theta‐band activity at both 3–4 and 11–12 months, while an increase in amplitudes at 9–13 Hz was observed as synchronized alpha‐band activity only at 11–12 months. It was concluded that brain electrical activities related to visual motion perception change during the first year of life, and these changes can be observed both in the VEP and induced activities of EEG. With adequate neurobiological development and locomotor experience infants around 1 year of age rely, more so than when they were younger, on structured optic flow and show a more adult‐like specialization for motion where faster oscillating cell assemblies have fewer but more specialized neurons, resulting in improved visual motion perception.     

Hemispheric Asymmetry and Regional Differences in Electroencephalographic Alpha Activity at the Wake-Sleep Transition

Electroencephalographic (EEG) alpha activity at the wake-sleep transition was studied in six right-handed adults in terms of hemispheric asymmetry and regional differences. Twelve-channel EEGs with linked mastoid references were recorded together with horizontal and vertical electro-oculograms (EOGs). Two types of alpha coefficient were obtained every 5.12 s by computing the relative proportion of right vs. left alpha band power and of anterior vs. posterior alpha band power. Four stages were scored using EEG sleep patterns (theta waves, vertex sharp waves, spindles, and K complex) and slow eye movement (SEM): stage W had neither EEG sleep patterns nor SEM; stage D1 had SEM and no EEG sleep patterns; stage D2 had theta waves or vertex sharp waves and SEM; stage S had spindles or K complex without SEM. It was found that the two types of alpha coefficient changed as a function of EEG-EOG stage and were correlated. Right-decreased and anterior-shifted alpha activities were manifest at stages D2 and S. Drowsiness was considered to be a heterogeneous state, exhibiting different spatial changes in alpha activity between stages D1 and D2.     

Exploring the effects of EEG signals on collision cases happening in the process of young drivers’ braking

Detecting mental states in drivers offers an opportunity to reduce accidents by triggering alerts and signaling the need for rest or renewed focus. Here we used electroencephalography (EEG) to measure brain signals in young drivers operating a driving simulator to detect mental states and predict accidents. We measured reaction times to unexpected hazardous events and correlated them with EEG signals measured from the frontal, parietal, and temporal cortices as well as the central sulcus (corresponding to motor cortex). We found that EEG signals in the relative beta (power in beta (13–30 Hz) relative to total power of the EEG (0.5–30 Hz)), alpha/delta, alpha/theta, beta/delta, beta/theta frequency bands were higher for collisions than successful collision avoidance, and that the key decision-making period is the 2nd second before braking. Importantly, a decision tree classifier trained on these neural signals predicted collision avoidance outcomes. Then based on random forest model, we extracted three critical neural signals (beta/delta_frontal, relative beta_parietal and relative beta_central Sulcus) to classify collision avoidance outcomes. Our findings suggest measuring EEG during driving may provide useful signals for enhancing driver safety.     

A strong parietal hub in the small-world network of coloured-hearing synaesthetes during resting state EEG

We investigated whether functional brain networks are different in coloured-hearing synaesthetes compared with non-synaesthetes. Based on resting state electroencephalographic (EEG) activity, graph-theoretical analysis was applied to functional connectivity data obtained from different frequency bands (theta, alpha1, alpha2, and beta) of 12 coloured-hearing synaesthetes and 13 non-synaesthetes. The analysis of functional connectivity was based on estimated intra-cerebral sources of brain activation using standardized low-resolution electrical tomography. These intra-cerebral sources of brain activity were subjected to graph-theoretical analysis yielding measures representing small-world network characteristics (cluster coefficients and path length). In addition, brain regions with strong interconnections were identified (so-called hubs), and the interconnectedness of these hubs were quantified using degree as a measure of connectedness. Our analysis was guided by the two-stage model proposed by Hubbard and Ramachandran (2005). In this model, the parietal lobe is thought to play a pivotal role in binding together the synaesthetic perceptions (hyperbinding). In addition, we hypothesized that the auditory cortex and the fusiform gyrus would qualify as strong hubs in synaesthetes. Although synaesthetes and non-synaesthetes demonstrated a similar small-world network topology, the parietal lobe turned out to be a stronger hub in synaesthetes than in non-synaesthetes supporting the two-stage model. The auditory cortex was also identified as a strong hub in these coloured-hearing synaesthetes (for the alpha2 band). Thus, our a priori hypotheses receive strong support. Several additional hubs (for which no a priori hypothesis has been formulated) were found to be different in terms of the degree measure in synaesthetes, with synaesthetes demonstrating stronger degree measures indicating stronger interconnectedness. These hubs were found in brain areas known to be involved in controlling memory processes (alpha1: hippocampus and retrosplenial area), executive functions (alpha1 and alpha2: ventrolateral prefrontal cortex; theta: inferior frontal cortex), and the generation of perceptions (theta: extrastriate cortex; beta: subcentral area). Taken together this graph-theoretical analysis of the resting state EEG supports the two-stage model in demonstrating that the left-sided parietal lobe is a strong hub region, which is stronger functionally interconnected in synaesthetes than in non-synaesthetes. The right-sided auditory cortex is also a strong hub supporting the idea that coloured-hearing synaesthetes demonstrate a specific auditory cortex. A further important point is that these hub regions are even differently operating at rest supporting the idea that these hub characteristics are predetermining factors of coloured-hearing synaesthesia.     

The effects of early foster care intervention on attention biases in previously institutionalized children in Romania

Children raised in institutions experience psychosocial deprivation that can negatively impact attention skills and emotion regulation, which subsequently may influence behavioral regulation and social relationships. The current study examined visual attention biases in 8‐year‐old children who were part of the Bucharest Early Intervention Project (BEIP). Relations among attention biases and concurrent social outcomes were also investigated. In early childhood, 136 children abandoned at birth or shortly thereafter into institutional care were randomized to receive a high‐quality foster care intervention or care‐as‐usual within the context of the Bucharest Early Intervention Project (BEIP). At 8 years of age, 50 care‐as‐usual, 55 foster care, and 52 community controls performed a behavioral dot‐probe task, and indices of attention biases to threat and positive stimuli were calculated. Concurrent data on social behavior were collected. Children placed into the foster care intervention had a significant attention bias toward positive stimuli, while children who received care‐as‐usual had a significant bias toward threat. Children in the foster care intervention had a significantly larger positive bias when compared to the care‐as‐usual group. A positive bias was related to more social engagement, more prosocial behavior, less externalizing disorders, and less emotionally withdrawn behavior. The magnitude of positive bias was predicted by age of placement into foster care among children with a history of institutionalization. An attention bias towards positive stimuli was associated with reduced risk for behavioral problems amongst children who experienced early psychosocial deprivation. Research assessing attention biases in children experiencing early environmental stress may refine our understanding of the mechanisms underlying risk for later psychiatric and social disorders and inform prevention efforts.     

Effects of a carbohydrate supplement upon resting brain activity

Glucose is a major energy source for the brain, and along with several monosaccharide derivatives as components of brain gangliosides, they play important roles in neurologic function. However, there is little information available on the role of glucose and other monosaccharides on resting brain activity. This study was designed to evaluate the effects of a single dose of a carbohydrate supplement containing glucose and several of its derivatives on resting brain activity in 20 healthy male college students. The supplement provided an insignificant amount of carbohydrate (3.9 g), protein (0.28 g), fat (0 g), and calories (14 kcal). The amount of glucose in the supplement was 0.5 g (1% the amount of glucose used in adult studies of cognitive functioning and memory). We hypothesized that the glyconutrient supplement would enhance brain activity associated with alertness and attention. The study design was double blind, with subjects randomly assigned to one of two orders, either carbohydrate supplement week one followed by placebo a week later, or the opposite. Electrical brain activity was monitored by 15 electrodes positioned at nine standard international 10–20 system locations, including three bilateral pairs at frontal, parietal, and occipital sites. Thirty minutes following ingestion of a placebo or carbohydrate supplement drink, EEG activity was recorded for 10-mins while subjects focused on a stationary visual target. Spectral power of resting brain activity was computed and analyzed contrasting the placebo and supplement groups. Relative to placebo, the carbohydrate supplement significantly enhanced power in three brain wave frequencies (theta, alpha, and beta) that are known to be associated with attention and arousal. Since changes were observed in the supplement but not placebo group, our study suggests that additional sugars in the glyconutritional supplement facilitate enhancement of brain electrical activity. Whether the apparent enhancement of arousal in baseline recordings is associated with improved task performance remains to be determined.     

Maturation of EEG power spectra in early adolescence: a longitudinal study

This study investigated the fine-grained development of the EEG power spectra in early adolescence, and the extent to which it is reflected in changes in peak frequency. It also sought to determine whether sex differences in the EEG power spectra reflect differential patterns of maturation. A group of 56 adolescents were tested at age 10 years and then at two further time-points approximately 18 months apart. The EEG was recorded during both eyes-closed and eyes-open conditions and Fourier transformed to provide estimates of absolute and relative spectral power at 0.5 Hz intervals from 0.5 to 40 Hz. The peak alpha frequency for each individual at each time-point was also determined for relative spectral power. Partial Least Squares (PLS) analysis was used to determine the combination of electrodes and frequencies that showed developmental change, or differed between the sexes. As a function of age, absolute delta and theta frequencies power decreased, and relative alpha2 and beta frequencies increased, replicating the standard findings of a decrease in lower, and increase in higher, frequencies with age. A small but significant increase in peak alpha frequency with age was detected. Moreover PLS analysis performed with individual alpha frequencies aligned to 10 Hz suggested that the age-related increase seen in alpha2 relative power was driven by changes in the peak frequency. Although males demonstrated higher alpha power than females, there were no sex differences in peak frequency, suggesting that there may be more to sex differences in EEG power than simply different rates of maturation between the two sexes.     

6-12岁儿童额叶自发脑电频谱相干的特点

EEG频谱相干分析发现额叶发育在童年中期存在可能的加速期。针对这一问题,本研究通过记录75名6至12岁正常儿童静坐和闭目状态下的自发脑电,分析δ、θ、α和β基本脑电频段下31对电极相干的变化情况,系统探索了该年龄段儿童额叶自发脑电频谱相干的变化特点,结果发现:θ波活动普遍强于α和β波活动;6至12岁儿童额叶内、额叶与其他脑叶间相干在整体上表现为随年龄增长而增加的趋势;额叶内、额叶与其他脑叶间相干在各频段均表现为7岁、11岁突增,10岁、12岁表现为高峰。上述结果支持6至12岁儿童额叶发育存在加速变化的结论。     

Effects of a Carbohydrate Supplement upon Resting Brain Activity

Glucose is a major energy source for the brain, and along with several monosaccharide derivatives as components of brain gangliosides, they play important roles in neurologic function. However, there is little information available on the role of glucose and other monosaccharides on resting brain activity. This study was designed to evaluate the effects of a single dose of a carbohydrate supplement containing glucose and several of its derivatives on resting brain activity in 20 healthy male college students. The supplement provided an insignificant amount of carbohydrate (3.9 g), protein (0.28 g), fat (0 g), and calories (14 kcal). The amount of glucose in the supplement was 0.5 g (1% the amount of glucose used in adult studies of cognitive functioning and memory). We hypothesized that the glyconutrient supplement would enhance brain activity associated with alertness and attention. The study design was double blind, with subjects randomly assigned to one of two orders, either carbohydrate supplement week one followed by placebo a week later, or the opposite. Electrical brain activity was monitored by 15 electrodes positioned at nine standard international 10-20 system locations, including three bilateral pairs at frontal, parietal, and occipital sites. Thirty minutes following ingestion of a placebo or carbohydrate supplement drink, EEG activity was recorded for 10-mins while subjects focused on a stationary visual target. Spectral power of resting brain activity was computed and analyzed contrasting the placebo and supplement groups. Relative to placebo, the carbohydrate supplement significantly enhanced power in three brain wave frequencies (theta, alpha, and beta) that are known to be associated with attention and arousal. Since changes were observed in the supplement but not placebo group, our study suggests that additional sugars in the glyconutritional supplement facilitate enhancement of brain electrical activity. Whether the apparent enhancement of arousal in baseline recordings is associated with improved task performance remains to be determined.     

Feedback related brain activity in a gambling task: A temporal analysis of EEG correlates

Lucchiari, C. & Pravettoni, G. (2010). Feedback related brain activity in a gambling task: A temporal analysis of EEG correlates. Scandinavian Journal of Psychology 51, 449–454. The pattern of neural correlates of feedback processing has been the subject of a number of studies, using both neuroimaging and electrophysiological recordings. A complex functional network was found to be activated after a choice in order to process a feedback and sustain an adaptive behavior. However, many aspects of this network are still unclear and further research is needed to better understand this process. We conducted an EEG study using a simple gambling task. Twenty three subjects participated to the study. We analyzed both EEG power spectrum and ERP components evoked by presentation of a feedback signal (money gain or loss) during a simple gambling task. Our data confirmed that a negative ERP component is present about 270 ms after feedback, particularly relevant following a choice with negative outcome. Furthermore, the theta and delta oscillatory activity seem to be correlated to a dynamic decision‐making process within specific cortical networks. In particular, theta activity showed a valence dependent development between 150 and 350 ms post‐feedback onset. Differently from previous studies (Cohen, Elger & Ranganath, 2007; Marco‐Pallares, Cucurell, Cunillera et al., 2008), we did not find any valence effect in beta range. However, our data are consistent with Christie and Tata (2009) , probably due to the nature of the gambling task used in both studies. In conclusion, our data, in line with some prior findings showed that the feedback related response is correlated to a complex pattern of cortical activation probably mediated by theta and delta activity.     

轻度认知功能障碍患者工作记忆中 脑电能量及皮质联络功能的变化特征

探讨轻度认知功能障碍患者（MCI）工作记忆状态下脑电能量及皮质联络功能的变化特征。被试为从社区选取的35名轻度认知功能障碍患者和34名健康志愿者。采用简单计算回忆方法,结果发现工作记忆加工过程中会引起4.0~18.0Hz范围内功率值的改变,且MCI组高于正常对照组;MCI患者在中央、顶、颞叶的半球间相干系数均显著高于正常对照组。研究结果提示MCI患者可能存在中央、顶、颞叶皮层的功能减退,工作记忆状态下通过代偿机制仍能维持加工的有效性     

Validity and reliability of electroencephalographic frontal alpha asymmetry and frontal midline theta as biomarkers for depression

Electroencephalographic (EEG) frontal alpha asymmetry (FAA) and frontal midline (FM) theta have been suggested as biomarkers for depression and anxiety, but have mostly been assessed in small and non‐clinical studies. In a clinical sample of 79 adults with depression (ICD‐10: F32), resting EEG and scales of depression (MADRS) and anxiety (HADS‐A) were measured at intake and after 3 months. FAA and FM theta values were referenced to a normative population database. Internal consistency, test‐retest reliability, and correlations with psychiatric tests were examined. Reliability was sufficient. However, FAA and FM theta values were close to the general population, and correlations with psychiatric tests were mostly small and non‐significant, with the exception of FAA on F7–F8 z‐scores and HADS‐A. We conclude that the validity of FAA and FM theta and therefore their potential as biomarkers for depression and anxiety remain unclear.     

Interindividual differences in alpha and theta power reflect memory performance

Previous research from our laboratory has shown that phasic or event-related changes in alpha and theta band power are related to memory performance. In this study, we test the hypothesis, whether tonic or ‘baseline’ power too is related to memory performance. The ongoing EEG was analyzed for a sample of 60 subjects during five experimental conditions: eyes closed, eyes open, memorizing words and counting backward in steps of 3 and 7. The results show that subjects with good memory performance have significantly larger upper alpha, but less theta and lower alpha power. In contrast to memory, good calculation performers have more beta and theta power than bad performers. These findings were obtained during actual task performance, but in a similar way also during the resting conditions eyes closed and open.     

Differences in EEG alpha activity related to giftedness

In three experiments, differences in EEG alpha activity between gifted (mean IQ = 137) and average (mean IQ = 105) individuals were investigated. EEG activity was monitored over 16 scalp locations. A fast Fourier transform was performed on 15 artifact-free 2-second chunks of data to derive a spectral power average in the alpha band (7.5–13 Hz). In the first experiment, EEG of gifted and average individuals during two relaxation phases—eyes closed and eyes open—was recorded. Gifted individuals showed higher EEG alpha power only while resting with eyes open. In the second experiment, gifted and average individuals solved two problems that were divided into phases of problem solving and preparing for problem solving (reading, making a plan of how to solve the problem). Significant differences were obtained only for the problem-solving stages. Gifted individuals in comparison with average ones showed higher alpha power (less mental effort) while solving the two problems. The third experiment investigated whether the lower mental activity displayed by gifted individuals was related to their ability to form more abstract schemata. For that purpose EEG was recorded while gifted and average individuals memorized lists of words and pictures that either allowed, or did not allow, for classification into more abstract categories. For both types of lists, gifted individuals displayed higher alpha power than average ones. The results obtained confirm the hypothesis that the higher EEG alpha power during information processing displayed by gifted individuals may derive from the nonuse of many brain areas not required for the problem at hand.     

The importance of maternal state of mind regarding attachment and infant age at placement to foster mothers' representations of their foster infants

Previous research has found that foster mother state of mind with respect to attachment and infant age at placement into foster care influence the developing foster mother–foster child relationship (Dozier, Albus, Stovall, & Bates, 2000; Stovall & Dozier, 2000). This study extends prior research by assessing factors related to foster mothers' representations of their foster infants. Participants were 48 foster mother–foster infant dyads in two mid‐Atlantic cities. We expected that foster mothers' states of mind and infant age at placement would be associated with foster mothers' acceptance of infants, commitment to infants, and belief in their influence on infants' development. Consistent with hypotheses, foster mothers' states of mind interacted with infant age at placement in predicting foster mothers' acceptance of their babies, and the extent to which foster mothers believed they could influence their infants' development. Specifically, autonomous foster mothers of babies placed before 12 months of age were more accepting and more likely to believe they could influence their infants' development compared to autonomous foster mothers of babies placed after 12 months of age, a pattern not seen for nonautonomous foster mothers. These results converge with other findings suggesting that timing of placement in foster care, and foster mothers' states of mind, are important to the developing foster mother–child relationship. ©2002 Michigan Association for Infant Mental Health.     

Reduced electroencephalographic coherence asymmetry in the Chernobyl accident survivors

An electroencephalograph (EEG) study was carried out from 1990 to 2006, using power spectra, averaged coherence, and integral EEG coherence asymmetry coefficients to compare 189 clean-up workers of the Chernobyl accident with 63 age-matched healthy controls. Most of the Chernobyl workers showed three abnormal EEG patterns, as indicated by EEG power mapping. The higher power, most prominent in slow alpha and theta bands, or in fast alpha frequencies, were observed in persons 3-5 years after the clean-up works (the early stage). The lower EEG power in alpha band was found in Chernobyl workers 10 or more years after the accident (the late stage). EEG coherence analysis revealed the existence of two stages in EEG alterations following the Chernobyl clean-up. In the early stage, an increase of EEG coherence in the central brain areas was observed, whereas at the later stage, a decrease of EEG coherence, most prominent in the frontal brain areas, and reduced brain asymmetry prevailed. These results allow us to propose that the described EEG signs may be a reflection of radiation-induced brain dysfunction at the late period after the Chernobyl clean-up and were similar to the EEG markers of brain ageing. The results, in comparison to data of the literature, provide additional support to the premature brain ageing hypothesis in Chernobyl survivors as a result of the radiation brain damage after-effect.