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

Examining the effects of prenatal alcohol exposure on performance of the sustained attention to response task in children with an FASD

Prenatal alcohol exposure (PAE), the leading known cause of childhood developmental disability, has long-lasting effects extending throughout the lifespan. It is well documented that children prenatally exposed to alcohol have difficulties inhibiting behavior and sustaining attention. Thus, the Sustained Attention to Response Task (SART), a Go/No-go paradigm, is especially well suited to assess the behavioral and neural functioning characteristics of children with PAE. In this study, we utilized neuropsychological assessment, parent/guardian questionnaires, and magnetoencephalography during SART random and fixed orders to assess characteristics of children 8-12 years old prenatally exposed to alcohol compared to typically developing children. Compared to neurotypical control children, children with a Fetal Alcohol Spectrum Disorder (FASD) diagnosis had significantly decreased performance on neuropsychological measures, had deficiencies in task-based performance, were rated as having increased Attention-Deficit/Hyperactivity Disorder (ADHD) behaviors and as having lower cognitive functioning by their caretakers, and had decreased peak amplitudes in Broadmann's Area 44 (BA44) during SART. Further, MEG peak amplitude in BA44 was found to be significantly associated with neuropsychological test results, parent/guardian questionnaires, and task-based performance such that decreased amplitude was associated with poorer performance. In exploratory analyses, we also found significant correlations between total cortical volume and MEG peak amplitude indicating that the reduced amplitude is likely related in part to reduced overall brain volume often reported in children with PAE. These findings show that children 8-12 years old with an FASD diagnosis have decreased amplitudes in BA44 during SART random order, and that these deficits are associated with multiple behavioral measures.

Prenatal alcohol exposure and cognition at midlife: Evidence of fluid cognition deficits in two cohorts

BACKGROUND

Prenatal alcohol exposure (PAE) impacts cognition in childhood and early adulthood. Here we evaluate the cognitive abilities of middle-aged adults with and without a history of PAE.

METHODS

Participants (N = 200) were recruited from longitudinal cohorts in the Atlanta and Seattle metropolitan areas and completed measures comprising the National Institutes of Health Toolbox's Fluid Cognition Composite.

RESULTS

We found that individuals with PAE had lower Fluid Cognition Summary scores and lower Dimensional Change Card Sort and Flanker task subtest scores than non-PAE controls, after accounting for both potentially confounding demographic variables using propensity scores and the effects of study site. When we evaluated the effects of PAE with and without dysmorphic physical features, we found that middle-aged adults in both groups had lower fluid cognition scores than non-PAE controls. However, only the presence of PAE with dysmorphic features was associated with lower performance on the Dimensional Change Card Sort Test and Flanker tasks.

CONCLUSION

While all participants with PAE had lower fluid cognition, those with PAE and dysmorphic features also exhibited specific deficits in their performance on measures of inhibition, attention, and cognitive flexibility. Thus, PAE is associated with ongoing cognitive deficits in middle adulthood, which can be observed most clearly among individuals with dysmorphic features.

Inhibitory control in young adult women with fetal alcohol syndrome: Findings from a pilot functional magnetic resonance imaging study

BACKGROUND

Executive dysfunction, especially impaired inhibitory control, is a common finding in individuals with fetal alcohol syndrome (FAS). Previous research has mostly focused on neural correlates of inhibitory deficits in children and adolescents. We investigated inhibitory functions and underlying cerebral activation patterns in young adult women with FAS.

METHODS

Task performance and functional magnetic resonance imaging (fMRI) data were acquired during a Go/NoGo (GNG) inhibition task in 19 young adult women with FAS and 19 healthy female control subjects. Whole-brain activation and task performance analyses were supplemented by region of interest (ROI) analyses of fMRI data within a predefined cognitive control network (CCN).

RESULTS

Task performance did not differ significantly between groups on errors of commission, associated with inhibitory control. Similarly, overall activation within the preselected ROIs did not differ significantly between groups for the main inhibitory contrast NoGo > Go. However, whole-brain analyses revealed activation differences in the FAS group when compared to controls under inhibitory conditions. This included hyperactivations in the left inferior frontal, superior temporal, and supramarginal gyri in the FAS group. Likewise, lateralization tendencies toward right-hemispheric ROIs were weaker in FAS subjects. In contrast to comparable inhibitory performance, attention-related errors of omission were significantly higher in the FAS group. Correspondingly, FAS subjects had lower activity in attention-related temporal and parietal areas.

CONCLUSIONS

The known alterations of inhibitory functions associated with prenatal alcohol exposure in children and adolescents were not seen in this adult sample. However, differential brain activity was observed, reflecting potential compensatory mechanisms. Secondary results suggest that there is impaired attentional control in young adult women with FAS.

Prenatal Exposure to Tobacco and Alcohol Alters Development of the Neonatal Auditory System

Prenatal exposures to alcohol (PAE) and tobacco (PTE) are known to produce adverse neonatal and childhood outcomes including damage to the developing auditory system. Knowledge of the timing, extent, and combinations of these exposures on effects on the developing system is limited. As part of the physiological measurements from the Safe Passage Study, Auditory Brainstem Responses (ABRs) and Transient Otoacoustic Emissions (TEOAEs) were acquired on infants at birth and one-month of age. Research sites were in South Africa and the Northern Plains of the U.S. Prenatal information on alcohol and tobacco exposure was gathered prospectively on mother/infant dyads. Cluster analysis was used to characterize three levels of PAE and three levels of PTE. Repeated-measures ANOVAs were conducted for newborn and one-month-old infants for ABR peak latencies and amplitudes and TEOAE levels and signal-to-noise ratios. Analyses controlled for hours of life at test, gestational age at birth, sex, site, and other exposure. Significant main effects of PTE included reduced newborn ABR latencies from both ears. PTE also resulted in a significant reduction of ABR peak amplitudes elicited in infants at 1-month of age. PAE led to a reduction of TEOAE amplitude for 1-month-old infants but only in the left ear. Results indicate that PAE and PTE lead to early disruption of peripheral, brainstem, and cortical development and neuronal pathways of the auditory system, including the olivocochlear pathway.

Differential Cortical Pattern in Auditory Task Oddball Paradigm in Children Exposed to Alcohol during Pregnancy

The negative effects of fetal alcohol exposure on child development are well documented. This study investigated the electrophysiological processing of cortical level acoustic signals in a group of 21 children prenatally exposed to alcohol. Participants aged 13-14 years at the time of the study were recruited from a longitudinal cohort sample. The study employed an observational, cross-sectional blind design and participants were divided into two groups: with and without fetal exposure to alcohol. Neurophysiological measures recorded N1, P2, N2, P3, P3a, and P3b components using the Oddball paradigm. Our results showed that the mothers' sociodemographic conditions at the time of birth, as well as the children's birth weights were homogeneous between the groups, though the Apgar score was lower in the exposed group (EG). The neurophysiological components that showed different results in the groups were P2 and P3a. P2 amplitude was higher in the midline central electrode (Cz) compared to the midline parietal electrode (Pz), demonstrating a group interaction for exposed children. For P3a there was an interaction of group and electrode position, and the EG showed higher amplitudes in Cz compared to the unEG. However, the Apgar score did not influence these results. In conclusion, children who had fetal exposure to alcohol presented electrophysiological recordings distinct from the control group. These differences occurred both in the P2 component - which reflects a bottom-up mechanism of auditory processing - as well as the P3a component, which may reflect the participation of supra-modal hearing mechanisms.

A review of studies exploring fetal alcohol spectrum disorders through eye tracking measures

The widespread cognitive and cerebral consequences of prenatal alcohol exposure have been established during the last decades, through the exploration of fetal alcohol spectrum disorders (FASD) using neuropsychological and neuroscience tools. This research field has recently benefited from the emergence of innovative measures, among which eye tracking, allowing a precise measure of the eye movements indexing a large range of cognitive functions. We propose a comprehensive review, based on PRISMA guidelines, of the eye tracking studies performed in populations with FASD. Studies were selected from the PsycINFO, PubMed and Scopus databases, and were evaluated through a standardized methodological quality assessment. Studies were classified according to the eye tracking indexes recorded (saccade characteristics, initial fixation, number of fixations, dwell time, gaze pattern) and the process measured (perception, memory, executive functions). Eye tracking data showed that FASD are mostly associated with impaired ocular perceptive/motor abilities (i.e., altered eye movements, centrally for saccade initiation), lower accuracy as well as increased error rates in saccadic eye movements involving working memory abilities, and reduced inhibitory control on saccades. After identifying the main limitations presented by the reviewed studies, we propose guidelines for future research, underlining the need to increase the standardization of diagnosis and evaluation tools, and to improve the methodological quality of eye tracking measures.

Fetal Alcohol Spectrum Disorders: A Review of the Neurobehavioral Deficits Associated With Prenatal Alcohol Exposure

In utero alcohol exposure can disrupt the development of the fetal brain and result in a wide range of neurobehavioral outcomes collectively known as fetal alcohol spectrum disorders (FASD). This paper provides a comprehensive review of the cognitive and behavioral outcomes of prenatal alcohol exposure, including domains of general intelligence, executive functioning, language development, learning and memory, adaptive functioning, academic performance, and concurrent psychopathology. In addition, the current status of the neurobehavioral profile of FASD and its potential as a diagnostic tool will be discussed.

Amplitude by Peak Interaction but No Evidence of Auditory Mismatch Response Deficits to Frequency Change in Preschool-Aged Children with Fetal Alcohol Spectrum Disorders

BACKGROUND

Prior studies indicate that the auditory mismatch response is sensitive to early alterations in brain development in multiple developmental disorders. Prenatal alcohol exposure is known to impact early auditory processing. The current study hypothesized alterations in the mismatch response in young children with fetal alcohol spectrum disorders (FASD).

METHODS

Participants in this study were 9 children with a FASD and 17 control children (Control) aged 3 to 6 years. Participants underwent magnetoencephalography and structural magnetic resonance imaging scans separately. We compared groups on neurophysiological mismatch negativity (MMN) responses to auditory stimuli measured using the auditory oddball paradigm. Frequent (1,000 Hz) and rare (1,200 Hz) tones were presented at 72 dB.

RESULTS

There was no significant group difference in MMN response latency or amplitude represented by the peak located ~200 ms after stimulus presentation in the difference time course between frequent and infrequent tones. Examining the time courses to the frequent and infrequent tones separately, repeated measures analysis of variance with condition (frequent vs. rare), peak (N100m and N200m), and hemisphere as within-subject factors and diagnosis and sex as the between-subject factors showed a significant interaction of peak by diagnosis (p = 0.001), with a pattern of decreased amplitude from N100m to N200m in Control children and the opposite pattern in children with FASD. However, no significant difference was found with the simple effects comparisons. No group differences were found in the response latencies of the rare auditory evoked fields.

CONCLUSIONS

The results indicate that there was no detectable effect of alcohol exposure on the amplitude or latency of the MMNm response to simple tones modulated by frequency change in preschool-aged children with FASD. However, while discrimination abilities to simple tones may be intact, early auditory sensory processing revealed by the interaction between N100m and N200m amplitude indicates that auditory sensory processing may be altered in children with FASD.

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.