The effects of fetal alcohol syndrome on response execution and inhibition: an event-related potential study

Behavioral and electrophysiological indices of inhibitory control in maltreated adolescents and nonmaltreated adolescents

Early adverse experiences are believed to have a profound effect on inhibitory control and the underlying neural regions. In the current study, behavioral and event-related potential (ERP) data were collected during a go/no-go task from adolescents who were involved with the child welfare system due to child maltreatment (n = 129) and low-income, nonmaltreated adolescents (n = 102). The nonmaltreated adolescents were more accurate than the maltreated adolescents on the go/no-go task, particularly on the no-go trials. Paralleling the results with typically developing populations, the nonmaltreated adolescents displayed a more pronounced amplitude of the N2 during the no-go trials than during the go trials. However, the maltreated adolescents demonstrated a more pronounced amplitude of the N2 during the go trials than during the no-go trials. Furthermore, while the groups did not differ during the go trials, the nonmaltreated adolescents displayed a more negative amplitude of the N2 than the maltreated adolescents during no-go trials. In contrast, there was not a significant group difference in amplitude of the P3. Taken together, these results provide evidence that the early adverse experiences encountered by maltreated populations impact inhibitory control and the underlying neural activity in early adolescence.

The neurocognitive profiles of justice involved people with foetal alcohol spectrum disorder: A systematic review

Foetal alcohol spectrum disorder (FASD) is highly prevalent in criminal justice settings. Despite increased awareness of the neurocognitive deficits among justice-involved individuals with FASD, no systematic evaluation of the literature in the field has been conducted to date. We aimed to conduct a systematic review of the literature on the neurocognitive profiles of justice-involved individuals with FASD, by searching five key electronic databases, dissertations database, and Google scholar, up to January 2021. The findings indicate that when contrasted with comparison groups, justice-involved individuals with FASD display significant impairment in a greater number of neurocognitive domains including intellectual capacity, executive function, language, academic achievements, motor skills, and adaptive living skills. The relatively small number of the studies included in the review, along with the confounding effects of comorbidities among study participants, precludes drawing firm conclusions about the true extent and implications of neurocognitive deficits in this population. To advance the field further, there is an urgent need to conduct robust studies involving larger samples of justice-involved individuals with FASD and suitable comparison groups. Advancing knowledge in the field can have important implications for understanding of the antecedents of offending behaviour in this population, and informing strategies for early identification and intervention.

Altered Neural Oscillations During Multisensory Integration in Adolescents with Fetal Alcohol Spectrum Disorder

BACKGROUND

Children with fetal alcohol spectrum disorder (FASD), who were exposed to alcohol in utero, display a broad range of sensory, cognitive, and behavioral deficits, which are broadly theorized to be rooted in altered brain function and structure. Based on the role of neural oscillations in multisensory integration from past studies, we hypothesized that adolescents with FASD would show a decrease in oscillatory power during event-related gamma oscillatory activity (30 to 100 Hz), when compared to typically developing healthy controls (HC), and that such decrease in oscillatory power would predict behavioral performance.

METHODS

We measured sensory neurophysiology using magnetoencephalography (MEG) during passive auditory, somatosensory, and multisensory (synchronous) stimulation in 19 adolescents (12 to 21 years) with FASD and 23 age- and gender-matched HC. We employed a cross-hemisphere multisensory paradigm to assess interhemispheric connectivity deficits in children with FASD.

RESULTS

Time-frequency analysis of MEG data revealed a significant decrease in gamma oscillatory power for both unisensory and multisensory conditions in the FASD group relative to HC, based on permutation testing of significant group differences. Greater beta oscillatory power (15 to 30 Hz) was also noted in the FASD group compared to HC in both unisensory and multisensory conditions. Regression analysis revealed greater predictive power of multisensory oscillations from unisensory oscillations in the FASD group compared to the HC group. Furthermore, multisensory oscillatory power, for both groups, predicted performance on the Intra-Extradimensional Set Shift Task and the Cambridge Gambling Task.

CONCLUSIONS

Altered oscillatory power in the FASD group may reflect a restricted ability to process somatosensory and multisensory stimuli during day-to-day interactions. These alterations in neural oscillations may be associated with the neurobehavioral deficits experienced by adolescents with FASD and may carry over to adulthood.

Differential Recruitment of Brain Regions During Response Inhibition in Children Prenatally Exposed to Alcohol

BACKGROUND

Response inhibition is a distinct aspect of executive function that is frequently impaired in children with fetal alcohol spectrum disorders (FASD). We used a Go/NoGo (GNG) task in a functional MRI protocol to investigate differential activation of brain regions in the response inhibition network in children diagnosed with full or partial fetal alcohol syndrome (FAS/PFAS), compared with healthy controls.

METHODS

A rapid, event-related task with 120 Go and 60 NoGo trials was used to study children aged 8 to 12 years-8 with FAS/PFAS, 17 controls. Letters were projected sequentially, with Go and NoGo trials randomly interspersed across the task. BOLD signal in the whole brain was contrasted for the correct NoGo minus correct Go trials between the FAS/PFAS and control groups.

RESULTS

Compared to the FAS/PFAS group, controls showed greater activation of the inferior frontal and anterior cingulate network linked to response inhibition in typically developing children. By contrast, the FAS/PFAS group showed greater BOLD response in dorsolateral prefrontal cortex and other middle prefrontal regions, suggesting compensation for inefficient function of pathways that normally mediate inhibitory processing. All group differences were significant after control for potential confounding variables. None of the effects of prenatal alcohol exposure on activation of the regions associated with response inhibition were attributable to the effects of this exposure on IQ.

CONCLUSIONS

This is the first FASD GNG study in which all participants in the exposed group met criteria for a diagnosis of full FAS or PFAS. Although FASD is frequently comorbid with attention deficit hyperactivity disorder, the pattern of brain activation seen in these disorders differs, suggesting that different neural pathways mediate response inhibition in FASD and that different interventions for FASD are, therefore, warranted.

An ERP Study of Response Inhibition in the Auditory Domain in Children with Fetal Alcohol Spectrum Disorders

BACKGROUND

Previous event-related potential (ERP) studies of response inhibition in children with fetal alcohol spectrum disorder (FASD) have used a visual Go/NoGo task to study the impact of prenatal alcohol exposure on response inhibition. No studies exist using auditory versions of the task; thus, it is unclear how the deficits observed in visual tasks translate into the auditory domain.

METHODS

This study examined ERPs using an auditory Go/NoGo paradigm in a sample of 35 school-age children-18 with heavy prenatal alcohol exposure and 17 normally developing controls.

RESULTS

Alcohol-exposed children performed as well as controls in terms of inhibiting their responses; however, their reaction times were significantly slower under the Go condition. As in the ERP visual Go/NoGo task previously administered to these children, group differences were seen in early perceptual processing, specifically related to stimulus discrimination, with a decrease in P2 amplitude in the alcohol-exposed group. The control group exhibited greater N2 amplitude in the NoGo compared to the Go condition while the alcohol-exposed group did not, suggesting a group difference in the neural substrates underlying conflict monitoring. The alcohol-exposed group demonstrated longer latency P3 with reduced amplitude, suggesting poorer allocation of attention. The alcohol-exposed group also exhibited a late positive component (LPC) similar to the one observed in the previous visual ERP study. This LPC may indicate compensatory neurophysiological function related to resetting of attentional control networks in preparation for the next trial. None of the ERP outcomes in this study were related to potential confounders which included cognitive and socioeconomic measures as well as ADHD diagnosis.

CONCLUSIONS

The observed ERP group differences point to elements of perceptual and attentional processing likely to be involved in the performance deficits often observed in children with FASD. We also observed changes in ERPs related to conflict monitoring/response inhibition, highlighting fetal alcohol-related effects on how the brain responds when there is need to identify and respond to environmental cues by switching away from a prepotent motor response to an inhibited state.

Inattention and impulsivity associated with prenatal alcohol exposure in a prospective cohort study with 11-years-old Brazilian children

This paper aimed to examine prenatal alcohol exposure and neuropsychological parameters and its relationship to impulsivity and inattention. Longitudinal prospective case-control cohort study starting with the risk drinking assessment of 449 third-trimester pregnant women, and a follow-up phase with 56 mother-child pairs (28 alcohol-exposed versus 28 non-exposed), with 11-12 years old children. The cohort study was followed up for 11 years. Quantity-frequency structured questions as well as AUDIT and T-ACE questionnaires were used to assess maternal alcohol consumption. A comprehensive set of neuropsychological testing instruments was used, including d2 Test, RCFT, RAVLT, WISC-III, among others. To control low IQ effects and intellectual disability diagnoses, as well differences in school skills biasing the neuropsychological comparison assessment, children with IQ <70 or learning disabilities were excluded of the sample. The two groups showed to be very comparable regarding sex, age, schooling, global IQ, laterality and maternal and social risk factors. Significant statistical differences were found for higher speed processing, total errors, and number of omission errors in the d2 Test. Likewise, there were differences found on RCFT test (lower scores for copy, immediate and delayed recall), and on semantic verbal fluency tests with a lower score. Prenatal alcohol-exposed children seems to be more inattentive and impulsive; they have poorer skills in verbal fluency, visuospatial working memory, and executive processing when compared to non-exposed children who were part of the same cohort sample.

Event-related potential differences in children supplemented with long-chain polyunsaturated fatty acids during infancy

Long-chain polyunsaturated fatty acids (LCPUFA) have been shown to be necessary for early retinal and brain development, but long-term cognitive benefits of LCPUFA in infancy have not been definitively established. The present study sought to determine whether LCPUFA supplementation during the first year of life would result in group differences in behavior and event-related potentials (ERPs) while performing a task requiring response inhibition (Go/No-Go) at 5.5 years of age. As newborns, 69 children were randomly assigned to infant formulas containing either no LCPUFA (control) or formula with 0.64% of total fatty acids as arachidonic acid (ARA; 20:4n6) and various concentrations of docosahexaenoic acid (DHA; 22:6n3) (0.32%, 0.64% or 0.96%) for the first 12 months of life. At 5.5 years of age, a task designed to test the ability to inhibit a prepotent response (Go/No-Go) was administered, yielding both event-related potentials (ERPs) and behavioral data. Behavioral measures did not differ between groups, although reaction times of supplemented children were marginally faster. Unsupplemented children had lower P2 amplitude than supplemented children to both Go and No-Go conditions. N2 amplitude was significantly higher on No-Go trials than Go trials, but only for supplemented children, resulting in a significant Group × Condition interaction. Topographical analysis of the ERPs revealed that the LCPUFA-supplemented group developed a novel period of synchronous activation (microstate) involving wider anterior brain activation around 200 ms; this microstate was not present in controls. These findings suggest that LCPUFA supplementation during the first 12 months of life exerts a developmental programming effect that is manifest in brain electrophysiology. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=oM2leg4sevs.

Sex differences in the relationship between heavy alcohol use, inhibition and performance monitoring: Disconnect between behavioural and brain functional measures

Previous research has reported mixed evidence of sex differences in the relationship between heavy alcohol use and deficits in behavioural control. Here, we examine sex differences in behavioural and event-related potential (ERP) markers of deficient inhibition. Participants were 71 young adults aged 18-21, who either drank heavily regularly (i.e., four standard drinks on one occasion, at least once a month, n=33, 20 male) or drank heavily less often than this (including never, n=38, 21 male). They completed a stop-signal task while ERPs were recorded. Increases in stop-signal reaction time, the time required to stop a response, were related to heavy drinking only in female participants. P3 amplitude, ERN amplitude and ERN latency did not display a significant interaction between group and sex. Heavy drinkers, regardless of sex, displayed a marginally larger successful>failed effect for P3 amplitude, and a marginally smaller error-related negativity. An apparent disconnect exists in behavioural and psychophysiological measures of sex differences in the relationship between heavy alcohol consumption and inhibitory processing; male heavy drinkers display only psychophysiological but not behavioural deficits, while female heavy drinkers display both. Future research may determine whether sex differences are apparent for other substances besides alcohol.

Cortical miscommunication after prenatal exposure to alcohol

We report on the effects of prenatal alcohol exposure on resting-state brain activity as measured by magnetoencephalography (MEG). We studied 37 subjects diagnosed with fetal alcohol spectrum disorder in one of three categories: fetal alcohol syndrome, partial fetal alcohol syndrome, and alcohol-related neurodevelopmental disorder. For each subject, the MEG signal was recorded for 60 s during rest while subjects lay supine. Using time series analysis, we calculated the synchronous neural interactions for all pair-wise combinations of 248 MEG sensors resulting in 30,628 partial correlations for each subject. We found significant differences from control subjects in 6.19 % of the partial zero-lag crosscorrelations (synchronous neural interactions; Georgopoulos et al. in J Neural Eng 4:349-355, 2007), with these differences localized in the right posterior frontal, right parietal, and left parietal/posterior frontal regions. These results show that MEG can detect functional brain differences in the individuals affected by prenatal exposure to alcohol. Furthermore, these differences may serve as a biomarker for future studies linking symptoms and signs to specific brain areas. This may lead to new insights into the neuropathology of fetal alcohol spectrum disorders.

Research Review: Executive function deficits in fetal alcohol spectrum disorders and attention-deficit/hyperactivity disorder - a meta-analysis

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD)-like symptoms are common in fetal alcohol spectrum disorders (FASD). FASD and ADHD groups both display executive function impairments; however, there is ongoing debate whether the pattern and magnitude of executive function deficits differs between these two types of disorders.

METHODS

An electronic literature search was conducted (PubMed, PsychInfo; 1972-2013) to identify studies comparing the executive functioning of children with FASD with ADHD or control groups. FASD groups included those with and without dysmorphy (i.e., FAS, pFAS, ARND, and other FASD diagnoses). Effect sizes (Hedges' g, standardized mean difference) were calculated. Random effects meta-analytic models were performed using the metafor package for R.

RESULTS

Fifty-one studies met inclusion criteria (FASD N = 2,115; ADHD N = 453; controls N = 1,990). Children with FASD showed the strongest and most consistent deficits in planning, fluency, and set-shifting compared to controls (Hedges' g = -0.94, -0.78) and children with ADHD (Hedges' g = -0.72, -0.32). FASD was associated with moderate to large impairments in working memory, compared to controls (Hedges' g = -.84, -.58) and small impairments relative to groups with ADHD (Hedges' g = -.26). Smaller and less consistent deficits were found on measures of inhibition and vigilance relative to controls (Hedges' g = -0.52, -0.31); FASD and ADHD were not differentiated on these measures. Moderator analyses indicated executive dysfunction was associated with older age, dysmorphy, and larger group differences in IQ. Sex and diagnostic system were not consistently related to effect size.

CONCLUSIONS

While FASD is associated with global executive impairments, executive function weaknesses are most consistent for measures of planning, fluency, and set-shifting. Neuropsychological measures assessing these executive function domains may improve differential diagnosis and treatment of FASD.

Aberrant development of post-movement beta rebound in adolescents and young adults with fetal alcohol spectrum disorders

Dependent on maternal (e.g. genetic, age) and exposure (frequency, quantity, and timing) variables, the effects of prenatal alcohol exposure on the developing fetus are known to vary widely, producing a broad range of morphological anomalies and neurocognitive deficits in offspring, referred to as fetal alcohol spectrum disorders (FASD). Maternal drinking during pregnancy remains a leading risk factor for the development of intellectual disabilities in the US. While few functional findings exist today that shed light on the mechanisms responsible for the observed impairments in individuals with FASD, animal models consistently report deleterious effects of early alcohol exposure on GABA-ergic inhibitory pathways. The post-motor beta rebound (PMBR), a transient increase of 15-30 Hz beta power in the motor cortex that follows the termination of movement, has been implicated as a neural signature of GABA-ergic inhibitory activity. Further, PMBR has been shown to be a reliable predictor of age in adolescents. The present study sought to investigate any differences in the development of PMBR between FASD and control groups. Beta event-related de-synchronization (ERD) and movement-related gamma synchronization (MRGS), although not clearly linked to brain maturation, were also examined. Twenty-two participants with FASD and 22 age and sex-matched controls (12-22 years old) underwent magnetoencephalography scans while performing an auditory oddball task, which required a button press in response to select target stimuli. The data surrounding the button presses were localized to the participants' motor cortices, and the time courses from the locations of the maximally evoked PMBR were subjected to wavelet analyses. The subsequent analysis of PMBR, ERD, and MRGS revealed a significant interaction between group and age in their effects on PMBR. While age had a significant effect on PMBR in the controls, no simple effects of age were detected in the FASD group. The FASD group additionally displayed decreased overall ERD levels. No group or age effects on MRGS were detected. The described findings provide further evidence for broad impairments in inhibitory processes in adolescents with FASD, possibly related to aberrant development of GABA-ergic pathways.

Effects of Developmental Alcohol Exposure on Potentiation and Depression of Visual Cortex Responses

BACKGROUND

Neuronal plasticity deficits are thought to underlie abnormal neurodevelopment in fetal alcohol spectrum disorders and in animal models of this condition. Previously, we found that alcohol exposure during a period that is similar to the last months of gestation in humans disrupts ocular dominance plasticity (ODP), as measured in superficial cortical layers. We hypothesize that exposure to alcohol can differentially affect the potentiation and depression of responses that are necessary for activity-dependent sprouting and pruning of neuronal networks. ODP is an established paradigm that allows the assessment of activity-dependent depression and potentiation of responses in vivo.

METHODS

Mouse pups were exposed to 3.6 to 5 g/kg of ethanol in saline daily or every other day between postnatal days 4 and 9. Visual cortex plasticity was then assessed during the critical period for ODP using 2 techniques that separately record in layers 4 (visually evoked potentials [VEPs]) and 2/3 (optical imaging of intrinsic signals [OI]).

RESULTS

We discovered a layer-specific effect of early alcohol exposure. Recording of VEPs from layer 4 showed that while the potentiation component of ODP was disrupted in animals treated with alcohol when compared with saline controls, the depression component of ODP (Dc-ODP) was unaltered. In contrast, OI from layers 2/3 showed that Dc-ODP was markedly disrupted in alcohol-treated animals when compared with controls.

CONCLUSIONS

Combined with our previous work, these findings strongly suggest that developmental alcohol exposure has a distinct and layer-specific effect on the potentiation and depression of cortical responses after monocular deprivation.

Reduced Efficiency and Capacity of Cognitive Control in Autism Spectrum Disorder

Cognitive control constrains mental operations to prioritize information that reaches conscious awareness and is essential to flexible, adaptive behavior under conditions of uncertainty. Cognitive control can be compromised by neurodevelopmental disorders such as autism spectrum disorder (ASD), which is characterized by the presence of social and communicative deficits, and restricted interests/repetitive behaviors. Although prior investigations have attempted to elucidate the nature of cognitive control in ASD, whether there is an underlying information processing deficit associated with cognitive control remains unclear. This study challenged cognitive control in 15 high-functioning adults with ASD and 15 typically developing (TD) controls using three novel tasks designed to systematically manipulate uncertainty. We aimed to investigate the efficiency of cognitive control in sequential information processing, cognitive control of nonsequential information processing across a range of cognitive loads and cognitive control capacity under time constraint. Results demonstrated that the ASD group performed less efficiently on sequential and nonsequential information processing, and had reduced cognitive control capacity under time constraint relative to the TD group. These findings suggest that inefficient cognitive control of information processing may be a fundamental deficit in ASD.

Executive Functioning in Children and Adolescents Prenatally Exposed to Alcohol: A Meta-Analytic Review

Prenatal alcohol exposure is associated with a constellation of adverse physical, neurocognitive and behavior outcomes, which comprise a continuum of disorders labeled Fetal Alcohol Spectrum Disorders (FASD). Extant research has consistently identified executive functions (EF) as a central impairment associated with FASD. Despite this, heterogeneity exists regarding the strength of the association between FASD and different EF, and this association has not yet been quantitatively synthesized. The current meta-analysis reviews 46 studies that compare children and adolescents with FASD to participants without FASD, on a variety of EF measures. In accordance with Miyake et al. Cognitive Psychology, 41, 49-100 (2000) three-factor model of EF, findings for the primary EF domains of working memory, inhibition, and set shifting are reviewed. Results indicate that children and adolescents with FASD demonstrate significant deficits across these EF, although the magnitude of effects diverged between EF, with working memory and inhibition yielding medium effects and set shifting yielding large effects. These results were moderated by sample characteristics, type of FASD diagnosis, and EF methodology. This quantitative synthesis offers novel future research directions.

An fMRI study of behavioral response inhibition in adolescents with and without histories of heavy prenatal alcohol exposure

Heavy prenatal alcohol exposure results in a range of deficits, including both volumetric and functional changes in brain regions involved in response inhibition such as the prefrontal cortex and striatum. The current study examined blood oxygen level-dependent (BOLD) response during a stop signal task in adolescents (ages 13-16 y) with histories of heavy prenatal alcohol exposure (AE, n=21) and controls (CON, n=21). Task performance was measured using percent correct inhibits during three difficulty conditions: easy, medium, and hard. Group differences in BOLD response relative to baseline motor responding were examined across all inhibition trials and for each difficulty condition separately. The contrast between hard and easy trials was analyzed to determine whether increasing task difficulty affected BOLD response. Groups had similar task performance and demographic characteristics, except for full scale IQ scores (AE<CON). The AE group demonstrated greater BOLD response in frontal, sensorimotor, striatal, and cingulate regions relative to controls, especially as task difficulty increased. When contrasting hard vs. easy inhibition trials, the AE group showed greater medial/superior frontal and cuneus BOLD response than controls. Results were unchanged after demographics and FAS diagnosis were statistically controlled. This was the first fMRI study to utilize a stop signal task, isolating fronto-striatal functioning, to assess response inhibition and the effects task difficulty in adolescents with prenatal alcohol exposure. Results suggest that heavy prenatal alcohol exposure disrupts neural function of this circuitry, resulting in immature cognitive processing and motor-association learning and neural compensation during response inhibition.

Prenatal tobacco exposure and response inhibition in school-aged children: an event-related potential study

Prenatal cigarette smoke exposure (PCSE) has been linked to problems in behavioral inhibition and attention deficit hyperactivity disorder in children in several epidemiological studies. We used event-related potentials (ERPs) to examine the effects of PCSE on neural correlates of inhibitory control of behavior. In a prospective longitudinal study on child development in the Canadian Arctic, we assessed 186 Inuit children (mean age=11.3years) on a visual Go/No-go response inhibition paradigm. PCSE was assessed through maternal recall. Potential confounders were documented from a maternal interview, and exposure to neurotoxic environmental contaminants was assessed from umbilical cord and child blood samples. PCSE was not related to behavioral performance on this simple response inhibition task. Nevertheless, this exposure was associated with smaller amplitudes of the N2 and P3 components elicited by No-go stimuli, suggesting an impairment in the neural processes underlying response inhibition. Amplitude of the No-go P3 component was also inversely associated with behavioral measures of externalizing problems and hyperactivity/impulsivity in the classroom. This study is the first to report neurophysiological evidence of impaired response inhibition in school-aged children exposed to tobacco smoke in utero. Effects were found on ERP components associated with conflict processing and inhibition of a prepotent response, indicating neurophysiological deficits that may play a critical role in the attention and behavior problems observed in children with PCSE.

Neurobehavioral, neurologic, and neuroimaging characteristics of fetal alcohol spectrum disorders

Alcohol consumption during pregnancy can have deleterious consequences for the fetus, including changes in central nervous system development leading to permanent neurologic alterations and cognitive and behavioral deficits. Individuals affected by prenatal alcohol exposure, including those with and without fetal alcohol syndrome, are identified under the umbrella of fetal alcohol spectrum disorders (FASD). While studies of humans and animal models confirm that even low to moderate levels of exposure can have detrimental effects, critical doses of such exposure have yet to be specified and the most clinically significant and consistent consequences occur following heavy exposure. These consequences are pervasive, devastating, and can result in long-term dysfunction. This chapter summarizes the neurobehavioral, neurologic, and neuroimaging characteristics of FASD, focusing primarily on clinical research of individuals with histories of heavy prenatal alcohol exposure, although studies of lower levels of exposure, particularly prospective, longitudinal studies, will be discussed where relevant.

Self-esteem modulates the time course of self-positivity bias in explicit self-evaluation

Researchers have suggested that certain individuals may show a self-positivity bias, rating themselves as possessing more positive personality traits than others. Previous evidence has shown that people evaluate self-related information in such a way as to maintain or enhance self-esteem. However, whether self-esteem would modulate the time course of self-positivity bias in explicit self-evaluation has never been explored. In the present study, 21 participants completed the Rosenberg self-esteem scale and then completed a task where they were instructed to indicate to what extent positive/negative traits described themselves. Behavioral data showed that participants endorsed positive traits as higher in self-relevance compared to the negative traits. Further, participants’ self-esteem levels were positively correlated with their self-positivity bias. Electrophysiological data revealed smaller N1 amplitude and larger late positive component (LPC) amplitude to stimuli consistent with the self-positivity bias (positive-high self-relevant stimuli) when compared to stimuli that were inconsistent with the self-positivity bias (positive-low self-relevant stimuli). Moreover, only in individuals with low self-esteem, the latency of P2 was more pronounced in processing stimuli that were consistent with the self-positivity bias (negative-low self-relevant stimuli) than to stimuli that were inconsistent with the self-positivity bias (positive-low self-relevant stimuli). Overall, the present study provides additional support for the view that low self-esteem as a personality variable would affect the early attentional processing.

Deficits in response inhibition correlate with oculomotor control in children with fetal alcohol spectrum disorder and prenatal alcohol exposure

Children with fetal alcohol spectrum disorder (FASD) or prenatal alcohol exposure (PAE) frequently exhibit impairment on tasks measuring inhibition. The objective of this study was to determine if a performance-based relationship exists between psychometric tests and eye movement tasks in children with FASD. Participants for this dataset were aged 5-17 years and included those diagnosed with an FASD (n=72), those with PAE but no clinical FASD diagnosis (n=21), and typically developing controls (n=139). Participants completed a neurobehavioral test battery, which included the NEPSY-II subtests of auditory attention, response set, and inhibition. Each participant completed a series of saccadic eye movement tasks, which included the antisaccade and memory-guided tasks. Both the FASD and the PAE groups performed worse than controls on the subtest measures of attention and inhibition. Compared with controls, the FASD group made more errors on the antisaccade and memory-guided tasks. Among the combined FASD/PAE group, inhibition and switching errors were negatively correlated with direction errors on the antisaccade task but not on the memory-guided task. There were no significant correlations in the control group. These data suggests that response inhibition deficits in children with FASD/PAE are associated with difficulty controlling saccadic eye movements which may point to overlapping brain regions damaged by prenatal alcohol exposure. The results of this study demonstrate that eye movement control tasks directly relate to outcome measures obtained with psychometric tests that are used during FASD diagnosis, and may therefore help with early identification of children who would benefit from a multidisciplinary diagnostic assessment.

Development of auditory event-related potentials in infants prenatally exposed to methadone

Developmental features of the P2 auditory ERP in a change detection paradigm were examined in infants prenatally exposed to methadone. Opiate dependent pregnant women maintained on methadone replacement therapy were recruited during pregnancy (N = 60). Current and historical alcohol and substance use, SES, and psychiatric status were assessed with a maternal interview during the third trimester. Medical records were used to collect information regarding maternal medications, monthly urinalysis, and breathalyzer to confirm comorbid drug and alcohol exposures. Between birth and 4 months infant ERP change detection performance was evaluated on one occasion with the oddball paradigm (.2 probability oddball) using pure-tone stimuli (standard = 1 kHz and oddball = 2 kHz frequency) at midline electrode sites, Fz, Cz, Pz. Infant groups were examined in the following developmental windows: 4-15, 16-32, or 33-120 days PNA. Older groups showed increased P2 amplitude at Fz and effective change detection performance at P2 not seen in the newborn group. Developmental maturation of amplitude and stimulus discrimination for P2 has been reported in developing infants at all of the ages tested and data reported here in the older infants are consistent with typical development. However, it has been previously reported that the P2 amplitude difference is detectable in neonates; therefore, absence of a difference in P2 amplitude between stimuli in the 4-15 days group may represent impaired ERP performance by neonatal abstinence syndrome or prenatal methadone exposure.

Effect of predictive cuing on response inhibition in children with heavy prenatal alcohol exposure

BACKGROUND

Heavy prenatal exposure to alcohol leads to widespread cognitive deficits, including problems with attention and response inhibition. This study examined blood oxygen level-dependent response in children with and without histories of heavy prenatal alcohol exposure during a task of response inhibition consisting of cued and noncued trials.

METHODS

Children and adolescents (ages 8 to 18 years) with (alcohol-exposed [AE] = 20) and without (control [CON] = 15) histories of heavy prenatal exposure to alcohol underwent functional magnetic resonance imaging while performing a go/no-go task. Unbeknownst to subjects, a predictive cue preceded the no-go stimulus in 87% of trials.

RESULTS

Groups were matched on demographic variables and did not differ on most measures of task performance. However, following cued stimuli, the AE group demonstrated a lower hit rate to go stimuli and more conservative response bias than the CON group. AE participants demonstrated more activation during no-go trials (inhibition) relative to go trials in the left precuneus, cingulate gyrus, anterior cingulate, and right medial frontal gyrus. During cue-dependent response inhibition, the AE group demonstrated less activation in the left precentral and postcentral gyrus compared to the CON group.

CONCLUSIONS

Consistent with previous studies of response inhibition, the AE group demonstrated greater frontal and parietal activation when attempting to inhibit prepotent responses than the CON group, despite similar rates of commission errors. This study further demonstrated that the AE group had impaired behavioral performance on cued trials and demonstrated less activation in precentral and postcentral gyri relative to the CON group on these trials. This investigation provides evidence of impaired behavioral and neural processing of sequential information in fetal alcohol spectrum disorders, which can help improve inhibition in typical populations.

An auditory Go/No-Go study of event-related potentials in children with fetal alcohol spectrum disorders

In this study event-related potentials (ERPs) were used to investigate the effects of prenatal alcohol exposure on response inhibition identified during task performance. ERPs were recorded during a auditory Go/No Go task in two groups of children with mean age of 12.8 years (11 years to 14.7 years): one diagnosed with fetal alcohol syndrome (FAS) or partial FAS (FAS/PFAS; n = 12) and a control group of children of same age whose mothers abstained from alcohol or drank minimally during pregnancy (n = 11). The children were instructed to push a button in response to the Go stimulus and not to press the button when the No Go stimulus were heard. Task performance accuracy did not differ between the two groups, however differences were observed in the ERP components: P2, N2, and P3. The P2 amplitude were larger for Go trials in both groups. The FAS/PFAS group showed slower N2 response to Go trials, suggesting a less efficient early classification of the stimulus. P3 showed larger amplitudes to No-Go vs. Go in both groups. The study has provided new evidence for inhibition deficits in FAS/PFAS subjects identified by ERPs.

Executive function predicts adaptive behavior in children with histories of heavy prenatal alcohol exposure and attention-deficit/hyperactivity disorder

BACKGROUND

Prenatal exposure to alcohol often results in disruption to discrete cognitive and behavioral domains, including executive function (EF) and adaptive functioning. In the current study, the relation between these 2 domains was examined in children with histories of heavy prenatal alcohol exposure, nonexposed children with a diagnosis of attention-deficit/hyperactivity disorder (ADHD), and typically developing controls.

METHODS

As part of a multisite study, 3 groups of children (8 to 18 years, M = 12.10) were tested: children with histories of heavy prenatal alcohol exposure (ALC, n = 142), nonexposed children with ADHD (ADHD, n = 82), and typically developing controls (CON, n = 133) who did not have ADHD or a history of prenatal alcohol exposure. Children completed subtests of the Delis-Kaplan Executive Function System (D-KEFS), and their primary caregivers completed the Vineland Adaptive Behavior Scales-II. Data were analyzed using regression analyses.

RESULTS

Analyses showed that EF measures were predictive of adaptive abilities, and significant interactions between D-KEFS measures and group were present. For the ADHD group, the relation between adaptive abilities and EF was more general, with 3 of the 4 EF measures showing a significant relation with adaptive score. In contrast, for the ALC group, this relation was specific to the nonverbal EF measures. In the CON group, performance on EF tasks did not predict adaptive scores over the influence of age.

CONCLUSIONS

These results support prior research in ADHD, suggesting that EF deficits are predictive of poorer adaptive behavior and extend this finding to include children with heavy prenatal exposure to alcohol. However, the relation between EF and adaptive ability differed by group, suggesting unique patterns of abilities in these children. These results provide enhanced understanding of adaptive deficits in these populations, as well as demonstrate the ecological validity of laboratory measures of EF.

Early adversity and neural correlates of executive function: implications for academic adjustment

Early adversity can negatively impact the development of cognitive functions, although little is known about whether such effects can be remediated later in life. The current study examined one facet of executive functioning - inhibitory control - among children who experienced institutional care and explored the impact of a foster care intervention within the context of the Bucharest Early Intervention Project (BEIP). Specifically, a go/nogo task was administered when children were eight years old and behavioral and event-related potential (ERP) measures were collected. Results revealed that children assigned to care as usual (i.e. institutional care) were less accurate and exhibited slower neural responses compared to children assigned to the foster care intervention and children who had never been institutionalized. However, children in both the care as usual and foster care groups exhibited diminished attention processing of nogo cues as assessed via P300 amplitude. Foster care children also showed differential reactivity between correct and error responses via the error-related negativity (ERN) as compared to children in the care as usual group. Combined, the results highlight perturbations in neural sources of behavioral and attention problems among children experiencing early adversity. Potential implications for academic adjustment in at risk children are discussed.

Auditory brainstem response (ABR) abnormalities across the life span of rats prenatally exposed to alcohol

BACKGROUND

Fetal alcohol syndrome (FAS) is a leading cause of neurodevelopmental impairments (NDIs) in developed countries. Sensory deficits can play a major role in NDI, yet few studies have investigated the effects of prenatal alcohol exposure on sensory function. In addition, there is a paucity of information on the lifelong effects of prenatal alcohol exposure. Thus, we sought to investigate the effects of prenatal alcohol exposure on auditory function across the life span in an animal model. Based on prior findings with prenatal alcohol exposure and other forms of adverse prenatal environments, we hypothesized that animals prenatally exposed to alcohol would show an age-dependent pattern of (i) hearing and neurological abnormalities as postweanling pups, (ii) a substantial dissipation of such abnormalities in young adulthood, and (iii) a resurgence of such abnormalities in middle-aged adulthood.

METHODS

Pregnant rats were randomly assigned to an untreated control (CON), a pair-fed control (PFC), or an alcohol-treated (ALC) group. The ALC dams were gavaged with 6 mg/kg alcohol daily from gestation day (GD) 6 to 21. The PFC dams were gavaged daily from GD6 to GD21 with an isocaloric and isovolumetric water-based solution of maltose-dextrins and pair-fed to the ALC dams. The CON dams were the untreated group to which the ALC and CON groups were compared. Hearing and neurological functions in the offspring were assessed with the auditory brainstem response (ABR) at the postnatal ages of 22, 220, and 520 days.

RESULTS

In accord with our hypothesis, ABR abnormalities were first observed in the postweanling pups, largely dissipated in young adulthood, and then resurged in middle-aged adulthood. This age-related pattern suggests that the ALC pups had a developmental delay that dissipated in young adulthood and an enhanced age-related deterioration that occurred in middle-aged adulthood. Such a pattern is consistent with the fetal programming hypothesis of adult-onset diseases (the Barker hypothesis).

CONCLUSIONS

Our findings have important clinical implications for the assessment and management of (i) childhood hearing disorders and their comorbidities (i.e., speech-and-language, learning, and attention deficit disorders) and (ii) enhanced age-related hearing and neurological degeneration in middle-aged adulthood that can result from prenatal alcohol exposure. We recommend hearing evaluation be a part of any long-term follow-up for FAS patients and patients exposed to any adverse prenatal environment.

Fetal alcohol spectrum disorders: neuropsychological and behavioral features

Heavy prenatal alcohol exposure can cause alterations to the developing brain. The resulting neurobehavioral deficits seen following this exposure are wide-ranging and potentially devastating and, therefore, are of significant concern to individuals, families, communities, and society. These effects occur on a continuum, and qualitatively similar neuropsychological and behavioral features are seen across the spectrum of effect. The term fetal alcohol spectrum disorders (FASD) has been used to emphasize the continuous nature of the outcomes of prenatal alcohol exposure, with fetal alcohol syndrome (FAS) representing one point on the spectrum. This paper will provide a comprehensive review of the neuropsychological and behavioral effects of heavy prenatal alcohol exposure, including a discussion of the emerging neurobehavioral profile. Supporting studies of lower levels of exposure, brain-behavior associations, and animal model systems will be included when appropriate.

Functional neuroimaging in the examination of effects of prenatal alcohol exposure

Functional neuroimaging offers the opportunity to understand the effect of prenatal alcohol exposure on the activities of the brain as well as providing a window into the relationship between neural activation and the behavioral outcomes that have been described in affected individuals. Several different methodologies have been used to examine the neurophysiological signal changes associated with different brain functions in prenatally exposed individuals and those diagnosed with fetal alcohol syndrome (FAS) or other fetal alcohol spectrum disorders (FASD). These include electroencephalography (EEG), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI). These studies demonstrate that it is feasible to use these technologies with this clinical population and that the damage to the central nervous system associated with prenatal alcohol exposure has widespread functional implications; however, currently, the literature in these areas is limited and unsystematic. Functional MRI with this clinical population has just begun to explore the implications of prenatal alcohol exposure with the first paper published in 2005. Other methodologies are similarly limited in scope. Nonetheless, these functional neuroimaging studies suggest that prenatal alcohol exposure, or a diagnosis of FAS, may lead to restrictions in neural efficiency or a global decrement in processing resources.

The effects of maternal binge drinking during pregnancy on neural correlates of response inhibition and memory in childhood

BACKGROUND

Although an extensive literature has documented a broad range of cognitive performance deficits in children with prenatal alcohol exposure, little is known about how the neurophysiological processes underlying these deficits may be affected. Event-related potentials (ERPs), which reflect task-specific changes in brain electrical activity, provide a method for examining multiple constituents of cognitive processing at the neural level.

METHODS

We recorded ERPs in 217 children from Inuit communities in Arctic Quebec (M age = 11.3 years) during 2 different tasks-Go/No-go response inhibition and continuous recognition memory. Children were classified as either alcohol-exposed (ALC) or controls (CON) depending on whether the mother reported binge drinking during pregnancy.

RESULTS

Both groups performed comparably in terms of accuracy and reaction time on the tasks, and both tasks elicited the expected effects on ERPs when responses were compared across conditions. However, the ALC group showed slower P2 latencies on Go/No-go, suggesting an altered neurophysiological response associated with initial visual processing of the stimuli. On the memory task, the ALC group showed reduced FN400 amplitude to New items, known as the familiarity effect, and reduced amplitude for the late positive component, possibly reflecting impairment in memory retrieval.

CONCLUSIONS

These findings show that, even in tasks in which alcohol-exposed children exhibit behavioral performance that is comparable to controls, fetal alcohol exposure is associated with altered neurophysiological processing of response inhibition and recognition memory. The data suggest that fetal alcohol exposure is associated with reduced efficiency in the initial extracting of the meaning of a stimulus, reduced allocation of attention to the task, and poorer conscious, explicit recognition memory processing.

A Proposed Model Standard for Forensic Assessment of Fetal Alcohol Spectrum Disorders

A model protocol is proposed for multidisciplinary assessment of Fetal Alcohol Spectrum Disorders (FASD) in the forensic context. Used effectively on both sides of the courtroom in the United States in criminal and post-conviction matters in state and federal courts, the model relies on the FASD literature and best-practice standards of care in terms of clinical as well as forensic evaluation. It is suggested that FASD diagnostic criteria for older adolescents and adults in the criminal system may need different emphasis if facial features have diminished with age and confirmation of prenatal exposure is impossible.

Effects of prenatal tobacco, alcohol and marijuana exposure on processing speed, visual-motor coordination, and interhemispheric transfer

Deficits in motor control are often reported in children with prenatal alcohol exposure (PAE). Less is known about the effects of prenatal tobacco exposure (PTE) and prenatal marijuana exposure (PME) on motor coordination, and previous studies have not considered whether PTE, PAE, and PME interact to affect motor control. This study investigated the effects of PTE, PAE, and PME as well as current drug use on speed of processing, visual-motor coordination, and interhemispheric transfer in 16-year-old adolescents. Data were collected as part of the Maternal Health Practices and Child Development Project. Adolescents (age 16, n=320) participating in a longitudinal study of the effects of prenatal substance exposure on developmental outcomes were evaluated in this study. The computerized Bimanual Coordination Test (BCT) was used to assess each domain of function. Other important variables, such as demographics, home environment, and psychological characteristics of the mother and adolescent were also considered in the analyses. There were significant and independent effects of PTE, PAE, and PME on processing speed and interhemispheric transfer of information. PTE and PME were associated with deficits in visual-motor coordination. There were no interactions between PAE, PTE, and PME. Current tobacco use predicted deficits in speed of processing. Current alcohol and marijuana use by the offspring were not associated with any measures of performance on the BCT.

An event-related potential study of response inhibition in ADHD with and without prenatal alcohol exposure

BACKGROUND

The attention and cognitive problems seen in individuals with a history of prenatal alcohol exposure often resemble those associated with attention deficit hyperactivity disorder (ADHD), but few studies have directly assessed the unique influence of each on neurobehavioral outcomes.

METHODS

We recorded event-related potentials (ERPs) during a Go/No-go response inhibition task in young adults with prospectively obtained histories of prenatal alcohol exposure and childhood ADHD.

RESULTS

Regardless of prenatal alcohol exposure, participants with childhood ADHD were less accurate at inhibiting responses. However, only the ADHD group without prenatal alcohol exposure showed a markedly diminished P3 difference between No-go and Go, which may reflect a more effortful strategy related to inhibitory control at the neural processing level.

CONCLUSION

This finding supports a growing body of evidence suggesting that the manifestation of idiopathic ADHD symptoms may stem from a neurophysiologic process that is different from the ADHD symptomatology associated with prenatal alcohol exposure. Individuals who have been prenatally exposed to alcohol and present with ADHD symptomatology may represent a unique endophenotype of the disorder, which may require different treatment approaches from those found to be effective with idiopathic ADHD.

Cognitive Event-Related Potentials and Alcoholism

The discipline of neuropsychiatry tries to bridge the gap between neurology and psychiatry in order to gain insight into the biological bases of psychiatric disorders. A principal tool is electrophysiological assessments, as, for instance, event-related potentials (ERPs). In this paper, we will review the current main findings concerning the status of cognitive ERPs in a specific psychiatric disease, i.e., chronic alcoholism. First, delayed P300 latency and reduced P300 amplitude are a common and robust finding in chronic alcoholics. Our aim will be to insert this empirical finding into the growing knowledge of molecular actions of alcohol and genetic patterns of alcohol dependence together with a more precise identification of alcohol-influenced neuronal and psychopathological processes. We will show how this may help us to reach a better understanding of this pathology. Second, an important set of data also pointed out that earlier ERP components, such as the N100, the mismatch negativity (MMN), the P100, and the N170, were also affected by chronic consumption of alcohol. Therefore, as the entire information-processing system seemed to be altered, these results deserved to be discussed, at least concerning their main clinical implications. Finally, although long term consequences of alcohol abuse have been extensively described, little is known about the detrimental effect on neural and cognitive processes of massive alcohol intake over a short period of time (e.g., binge drinking). Recent data on this new and challenging issue will be outlined.