Auditory event-related potentials (ERPs) and mismatch negativity (MMN) in healthy children and those with attention-deficit or tourette/tic symptoms

Automatic sensory change processing in adults with attention deficit and hyperactivity disorder: a visual mismatch negativity study

In addition to higher-order executive functions, underlying sensory processing ability is also thought to play an important role in Attention-Deficit/Hyperactivity Disorder (AD/HD). An event-related potential feature, the mismatch negativity, reflects the ability of automatic sensory change processing and may be correlated with AD/HD symptoms and executive functions. This study aims to investigate the characteristics of visual mismatch negativity (vMMN) in adults with AD/HD. Twenty eight adults with AD/HD and 31 healthy controls were included in this study. These two groups were matched in age, IQ and sex. In addition, both groups completed psychiatric evaluations, a visual ERP task used to elicit vMMN, and psychological measures about AD/HD symptoms and day-to-day executive functions. Compared to trols, the late vMMN (230-330 ms) was significantly reduced in the AD/HD group. Correlation analyses showed that late vMMN was correlated with executive functions but not AD/HD symptoms. However, further mediation analyses showed that different executive functions had mediated the relationships between late vMMN and AD/HD symptoms. Our findings indicate that the late vMMN, reflecting automatic sensory change processing ability, was impaired in adults with AD/HD. This impairment could have negative impact on AD/HD symptoms via affecting day-to-day executive functions.

Auditory P3a response to native and foreign speech in children with or without attentional deficit

The aim of this study was to investigate the attentional mechanism in speech processing of native and foreign language in children with and without attentional deficit. For this purpose, the P3a component, cognitive neuromarker of the attentional processes, was investigated in a two-sequence two-deviant oddball paradigm using Finnish and English speech items via event-related potentials (ERP) technique. The difference waves reflected the temporal brain dynamics of the P3a response in native and foreign language contexts. Cluster-based permutation tests evaluated the group differences over the P3a time window. A correlation analysis was conducted between the P3a response and the attention score (ATTEX) to evaluate whether the behavioral assessment reflected the neural activity. The source reconstruction method (CLARA) was used to investigate the neural origins of the attentional differences between groups and conditions. The ERP results showed a larger P3a response in the group of children with attentional problems (AP) compared to controls (CTR). The P3a response differed statistically between the two groups in the native language processing, but not in the foreign language. The ATTEX score correlated with the P3a amplitude in the native language contrasts. The correlation analyses hint at some hemispheric brain activity difference in the frontal area. The group-level CLARA reconstruction showed activation in the speech perception and attention networks over the frontal, parietal, and temporal areas. Differences in activations of these networks were found between the groups and conditions, with the AP group showing higher activity in the source level, being the origin of the ERP enhancement observed on the scalp level.

Effects of methylphenidate on mismatch negativity and P3a amplitude of initially psychostimulant-naïve, adult ADHD patients

BACKGROUND

Deficient information processing in ADHD theoretically results in sensory overload and may underlie the symptoms of the disorder. Mismatch negativity (MMN) and P3a amplitude reflect an individual's detection and subsequent change in attention to stimulus change in their environment. Our primary aim was to explore MMN and P3a amplitude in adult ADHD patients and to examine the effects of methylphenidate (MPH) on these measures.

METHODS

Forty initially psychostimulant-naïve, adult ADHD patients without comorbid ASD and 42 matched healthy controls (HC) were assessed with an MMN paradigm at baseline. Both groups were retested after 6 weeks, in which patients were treated with MPH.

RESULTS

Neither significant group differences in MMN nor P3a amplitude were found at baseline. Although 6-week MPH treatment significantly reduced symptomatology and improved daily functioning of the patients, it did not significantly affect MMN amplitude; however, it did significantly reduce P3a amplitude compared to the HC. Furthermore, more severe ADHD symptoms were significantly associated with larger MMN amplitudes in the patients, both at baseline and follow-up.

CONCLUSION

We found no evidence for early information processing deficits in patients with ADHD, as measured with MMN and P3a amplitude. Six-week treatment with MPH decreased P3a but not MMN amplitude, although more severe ADHD-symptoms were associated with larger MMN amplitudes in the patients. Given that P3a amplitude represents an important attentional process and that glutamate has been linked to both ADHD and MMN amplitude, future research should investigate augmenting MPH treatment of less responsive adults with ADHD with glutamatergic antagonists.

P3b Amplitude and Latency in Tic Disorders: A Meta-Analysis

P3b is an event-related potential (ERP) that may be abnormal in patients with tic disorders (TD), but evidence has been inconsistent. Given the possible association between P3b and TD and the need for biomarkers for TD, the primary objective of this meta-analysis was to characterize P3b in patients with TD in comparison to healthy controls (HCs).

METHODS

By searching PubMed, Embase, Web of Science, SCOPUS, Medline, and Google Scholar, we identified studies that compared P3b between TD patients and HCs. The amplitude and latency of P3b were then analyzed. Subgroup analyses were conducted to investigate the influence of different experimental factors on P3b indices.

RESULT

Overall, 19 articles involving 388 cases and 414 controls were evaluated. There were no significant abnormalities in P3b amplitude and latency in TD patients. The P3b amplitude of the TD patients was significantly decreased during the oddball task, and the P3b amplitude of the adult TD patients was also significantly decreased.

CONCLUSION

TD patients may have an abnormal P3b compared to HCs under specified conditions.

Long Latency Auditory Evoked Responses in the Identification of Children With Central Auditory Processing Disorders: A Scoping Review

PURPOSE

The long latency auditory evoked responses (LLAERs), originating in the auditory cortex, are often considered a biomarker for maturity in the central auditory system and may therefore be useful in the evaluation of children with central auditory processing disorder (CAPD). However, the characteristics of the LLAERs elicited in this population have not been widely described, and clinical applications remain unclear. The goal of this scoping review was to investigate if LLAERs can be used to identify children with CAPD.

METHOD

A systematic search strategy was used to identify studies that analyzed the latencies and amplitudes of P1, N1, P2, and N2 waveforms of the LLAERs. The online databases, including Embase, Web of Science, MEDLINE, PubMed, ProQuest, and CINAHL, as well as the gray literature were searched for papers published in English and French between January 1980 and May 2021.

RESULTS

Seventeen papers met the eligibility criteria and were included in the study. Four papers had pre- and posttraining study designs, and the remaining studies were cross-sectional. Several studies reported significant differences in LLAERs between children with CAPD and their normal-hearing peers, and the results tended toward longer latencies and smaller amplitudes regardless of LLAER waves considered. N1 and/or N2 results were most likely to reveal significant differences between children with CAPD and normal-hearing controls and could potentially be considered a biomarker for CAPD.

CONCLUSIONS

It seems that LLAER assessments, especially waves N1 and N2, might assist in better identification of CAPD children. However, considering heterogeneity in the methodology among the included studies, the results should be interpreted with caution. Well-designed studies on children with confirmed CAPD using standard diagnostic and assessment protocols are suggested.

Mismatch negativity and P3a in drug-naive adults with attention-deficit hyperactivity disorder

BACKGROUND

Individuals with attention-deficit hyperactivity disorder (ADHD) often display over-response to stimuli that are irrelevant to the ongoing task, and their attentional abilities disproportionately worsen in the presence of competing stimuli. Auditory event-related potentials (ERPs) such as mismatch negativity (MMN) and P3a using the passive oddball paradigm have been studied in children and adolescents with ADHD. Still, there is no such data for adults with ADHD. This study aimed to compare the MMN and P3a and their clinical and neurocognitive correlations between drug-naive adults with ADHD and control adults.

METHODS

We recruited 52 adults with ADHD (26.5 ± 6.2 years), and 62 age-matched controls (25.6 ± 5.6 years). They received the psychiatric interviews, auditory ERP, the Conners' continuous performance test (CCPT), and the Cambridge gambling test (CGT). They also completed the questionnaires about ADHD symptoms and real-world executive functions. MMN and P3a were assessed during a passive duration-deviant auditory oddball paradigm from the midline electrodes Cz.

RESULTS

Adults with ADHD demonstrated smaller Cz MMN amplitude, more severe ADHD symptoms, poorer attention profiles (CCPT), and a wide range of executive dysfunctions than controls. As for the correlates, Cz peak amplitude of MMN correlated with inattention symptoms, executive dysfunctions, attentional vigilance (CCPT), and decision-making (CGT) in ADHD adults but only with decision-making in controls.

CONCLUSIONS

Our findings that smaller amplitude of MMN and its differential associated pattern with inattention, real-world executive dysfunction, and decision-making, in drug-naive adults with ADHD from adult controls, provide evidence to support the potential electrophysiological biomarker for adult ADHD.

Sensory hypersensitivity in Tourette syndrome: A review

Tourette syndrome (TS) is a neurodevelopmental disorder defined by tics, but most patients also experience bothersome sensory phenomena, in the form of premonitory urges and/or sensory hypersensitivity. Whereas premonitory urges are temporally paired with tics, sensory hypersensitivity is a constant, heightened awareness of external and/or internal stimuli. The intensity of sensory hypersensitivity does not strongly correlate with the severity of tics or premonitory urges, suggesting it is a dissociable clinical phenomenon. At least 80% of TS patients report subjectively enhanced perception of various sensory stimuli. These same patients demonstrate normal static detection thresholds. However, individuals with TS habituate abnormally to repetitive stimuli, indicating incapacity to appropriately filter redundant sensory input, i.e. impaired sensory gating. Physiologic support for this hypothesis is provided by abnormal pre-pulse inhibition (PPI) and event-related potential (ERP) investigations. Preclinical data implicates parvalbumin-positive (PV+) interneuron dysfunction in altered sensory gating in TS and other neurodevelopment disorders. Studies probing TS sensory hypersensitivity must methodically account for comorbid psychiatric conditions, namely obsessive compulsive disorder (OCD), attention deficit hyperactivity disorder (ADHD), and autism spectrum disorder (ASD), as these entities appear to involve pathophysiologic processes shared with TS. The presence of psychiatric comorbidities in TS is associated with even more profound sensory processing dysfunction. A deepened understanding of TS sensory hypersensitivity will afford novel insights into disease mechanisms, clinical phenotype, and therapeutic management.

Event-Related Potentials in ADHD Associated With Tuberous Sclerosis Complex: A Possible Biomarker of Symptoms Severity?

Background and Aim: Tuberous sclerosis complex (TSC) is associated with a high rate of attention deficit-hyperactivity disorder (ADHD), usually with more severe symptoms than in idiopathic cases. Event-related potentials have been used in idiopathic ADHD, and they have been proposed as a possible biomarker of symptoms severity. Aim of this study was to investigate event-related potential (ERP) characteristics in patients with ADHD secondary to TSC, compared to patients with drug-naive idiopathic ADHD and healthy controls (HCs), to investigate whether (1) distinct clinical features can be due to different pathophysiological mechanisms, and (2) ERPs may reliably predict ADHD symptoms severity in TSC.

Materials and Methods: We enrolled 13 patients with idiopathic ADHD (iADHD), 6 patients with ADHD associated with TSC (tscADHD), and 14 age-matched HCs (7–17 years). All of them underwent ERP recording, with mismatch negativity (MMN) preceding the P300 recording. All patients underwent neurocognitive evaluations.

Results: Mismatch negativity latency was shorter in iADHD (P = 0.04) and tscADHD (P = 0.06) than in HC, with no difference between patients' groups. Mismatch negativity amplitude was significantly higher in patients (both iADHD and tscADHD) than in HC. The P300 amplitude was significantly lower in iADHD patients than in both tscADHD patients (P = 0.03) and HCs (P < 0.001). No difference was found between tscADHD patients and HCs (P = 0.2).

Conclusion: While patients with iADHD present lower P300 amplitude than HC, in tscADHD patients P300 amplitude was not different from that in HC, suggesting that in TSC P300 amplitude does not really reflect symptom severity.

The electrophysiology correlation of the cognitive bias in anxiety under uncertainty

The intolerance of uncertainty (IU) model holds that excessive emotional response under uncertain conditions is conducive to the maintenance of anxiety, and individuals with a high anxiety level may exhibit a negative bias and experience anxiety when processing uncertain information. However, the dynamic electrophysiological correlation of this negative bias is not clear. Therefore, we used an adapted study–test paradigm to explore the changes in the electroencephalography (EEG) of subjects when processing uncertain cues and certain cues (certain neutral and certain threatening) and correlated the differences with anxiety level. The behavioral results showed that there was a significant positive correlation between the trait anxiety score and β value under the threatening condition, which indicated that individuals with high trait anxiety take a more conservative approach in the face of negative stimuli. The results of EEG showed that during the test stage, the components N1 and P2, which are related to early perception, had significant conditional main effects. Meanwhile, under uncertain conditions, the N1 peak was positively correlated with the state anxiety score. In the study stage, we found that the N400 component was significantly larger in the early study stage than in the late study stage under uncertain conditions. In sum, individuals with high anxiety levels had a negative bias in the early cue processing of the test stage, and anxiety did not affect the study stage.

Associations between the Mismatch-negativity Potential and Symptom Severity in Medication-naïve Children and Adolescents with Symptoms of Attention Deficit/hyperactivity Disorder

OBJECTIVE

The mismatch negativity (MMN) event-related potential is an index of the pre-attentive stage of neural auditory information processing and an electrophysiological signal indicative of the integrity of auditory information processing with regard to the attention deficit symptom of attention deficit hyperactivity disorder (ADHD). We investigated the association between the MMN amplitude and latency in frontal brain regions and symptom severity in children with ADHD and subclinical ADHD symptoms.

METHODS

This study included 29 children: 16 (10 boys; mean age, 13.06 ± 3.67 years) with ADHD (ADHD group) and 13 (eight boys; mean age, 13.40 ± 3.31 years) with sub-clinical ADHD symptoms (subclinical ADHD group). We performed the following assessments: Korean ADHD rating scale-IV (K-ARS-IV), children depression inventory, state/trait anxiety inventory for children, and MMN (measured at Fz, FCz, Cz, and CPz).

RESULTS

There were no sex or mean age differences between the groups (χ2 = -0.01, p = 0.958; Z = -1.88, p = 0.060, respectively). The ADHD group had a significantly higher mean K-ARS-IV score (26.13 ± 9.56 vs. 17.15 ± 11.73, Z = -2.11, p = 0.035). Significant differences were found according to symptom severity in the MMN amplitude at FCz (Z = -2.11, p = 0.035) and MMN latency at Fz and FCz (Z = -2.48, p = 0.013; Z = -2.57, p = 0.010). The K-ARS-IV, K-ARS inattention subscale, and K-ARS hyperactivity-impulsivity subscale scores in the ADHD group correlated significantly with the MMN amplitude at Cz and CPz.

CONCLUSION

This study found differences in the MMN amplitude and latency according to the severity of ADHD symptoms and identified MMN as a potential adjunct to the diagnosis of ADHD.

Interaction of Background Noise and Auditory Hallucinations on Phonemic Mismatch Negativity (MMN) and P3a Processing in Schizophrenia

Auditory hallucinations (AHs) are among the cardinal symptoms of schizophrenia (SZ). During the presence of AHs aberrant activity of auditory cortices have been observed, including hyperactivation during AHs alone and hypoactivation when AHs are accompanied by a concurrent external auditory competitor. Mismatch negativity (MMN) and P3a are common ERPs of interest within the study of SZ as they are robustly reduced in the chronic phase of the illness. The present study aimed to explore whether background noise altered the auditory MMN and P3a in those with SZ and treatment-resistant AHs.

METHODS

MMN and P3a were assessed in 12 hallucinating patients (HPs), 11 non-hallucinating patients (NPs) and 9 healthy controls (HCs) within an auditory oddball paradigm. Standard (P = 0.85) and deviant (P = 0.15) stimuli were presented during three noise conditions: silence (SL), traffic noise (TN), and wide-band white noise (WN).

RESULTS

HPs showed significantly greater deficits in MMN amplitude relative to NPs in all background noise conditions, though predominantly at central electrodes. Conversely, both NPs and HPs exhibited significant deficits in P3a amplitude relative to HCs under the SL condition only.

SIGNIFICANCE

These findings suggest that the presence of AHs may specifically impair the MMN, while the P3a appears to be more generally impaired in SZ. That MMN amplitudes are specifically reduced for HPs during background noise conditions suggests HPs may have a harder time detecting changes in phonemic sounds during situations with external traffic or "real-world" noise compared to NPs.

Association between fat-soluble nutrient status and auditory and visual related potentials in newly diagnosed non-screened infants with cystic fibrosis: A case-control study

Nutritional deficiencies often precede the diagnosis of cystic fibrosis (CF) in infants, and occur at a stage where the rapidly developing brain is more vulnerable to insult. We aim to compare fat-soluble nutrient status of newly diagnosed non-screened infants with CF to that of healthy infants, and explore the association with neurodevelopment evaluated by electroencephalography (EEG). Our results show that CF infants had lower levels of all fat-soluble vitamins and docosahexaenoic acid (DHA) compared to controls. The auditory evoked potential responses were higher in CF compared to controls whereas the visual components did not differ between groups. DHA levels were correlated with auditory evoked potential responses. Although resting state frequency power was similar between groups, we observed a negative correlation between DHA levels and low frequencies. This study emphasizes the need for long-term neurodevelopmental follow-up of CF infants and pursuing intervention strategies in the future.

Event-Related Potential Analysis of ADHD and Control Adults During a Sustained Attention Task

Background. Event-related potentials (ERPs) of attention deficit hyperactivity disorder (ADHD) population have been extensively studied using the time-domain representation of signals but time-frequency domain techniques are less explored. Although, adult ADHD is a proven disorder, most of the electrophysiological studies have focused only on children with ADHD. Methods. ERP data of 35 university students with ADHD and 35 control adults were recorded during visual continuous performance task (CPT). Gray level co-occurrence matrix-based texture features were extracted from time-frequency (t-f) images of event-related EEG epochs. Different ERP components measures, that is, amplitudes and latencies corresponding to N1, N2, and P3 components were also computed relative to standard and target stimuli. Results. Texture analysis has shown that the mean value of contrast, dissimilarity, and difference entropy is significantly reduced in adults with ADHD than in control adults. The mean correlation and homogeneity in adults with ADHD were significantly increased as compared with control adults. ERP components analysis has reported that adults with ADHD have reduced N1 amplitude to target stimuli, reduced N2 and P3 amplitude to both standard and target stimuli than controls. Conclusions. The differences in texture features obtained from t-f images of ERPs point toward altered information processing in adults with ADHD during a cognitive task. Findings of reduction in N1, N2, and P3 components highlight deficits of early sensory processing, stimulus categorization, and attentional resources, respectively, in adults with ADHD.

Disrupted Executive Function and Aggression in Individuals With a History of Adverse Childhood Experiences: An Event-Related Potential Study

Here, we explored the functional and neural mechanisms underlying aggression related to adverse childhood experiences. We assessed behavioral performance and event-related potentials during a go/no-go and N-back paradigm. The participants were 15 individuals with adverse childhood experiences and high aggression (ACE + HA), 13 individuals with high aggression (HA), and 14 individuals with low aggression and no adverse childhood experiences (control group). The P2 latency (initial perceptual processing) was longer in the ACE + HA group for the go trials. The HA group had a larger N2 (response inhibition) than controls for the no-go trials. Error-related negativity (error processing) in the ACE + HA and HA groups was smaller than that of controls for false alarm go trials. Lastly, the ACE + HA group had shorter error-related negativity latencies than controls for false alarm trials. Overall, our results reveal the neural correlates of executive function in aggressive individuals with ACEs.

Left and right reaction time differences to the sound intensity in normal and AD/HD children

OBJECTIVES

Right hemisphere, which is attributed to the sound intensity discrimination, has abnormality in people with attention deficit/hyperactivity disorder (AD/HD). However, it is not studied whether the defect in the right hemisphere has influenced on the intensity sensation of AD/HD subjects or not. In this study, the sensitivity of normal and AD/HD children to the sound intensity was investigated.

METHODS

Nineteen normal and fourteen AD/HD children participated in the study and performed a simple auditory reaction time task. Using the regression analysis, the sensitivity of right and left ears to various sound intensity levels was examined.

RESULTS

The statistical results showed that the sensitivity of AD/HD subjects to the intensity was lower than the normal group (p < 0.0001). Left and right pathways of the auditory system had the same pattern of response in AD/HD subjects (p > 0.05). However, in control group the left pathway was more sensitive to the sound intensity level than the right one (p = 0.0156).

CONCLUSIONS

It can be probable that the deficit of the right hemisphere has influenced on the auditory sensitivity of AD/HD children. The possible existent deficits of other auditory system components such as middle ear, inner ear, or involved brain stem nucleuses may also lead to the observed results. The development of new biomarkers based on the sensitivity of the brain hemispheres to the sound intensity has been suggested to estimate the risk of AD/HD. Designing new technique to correct the auditory feedback has been also proposed in behavioral treatment sessions.

Mismatch negativity and P3a amplitude in young adolescents with first-episode psychosis: a comparison with ADHD

BACKGROUND

Deficient mismatch negativity (MMN) has been proposed as a candidate biomarker in schizophrenia and may therefore be potentially useful in early identification and intervention in early onset psychosis. In this study we explored whether deficits in the automatic orienting and reorienting responses, measured as MMN and P3a amplitude, are present in young adolescents with first-episode psychosis (FEP) and whether findings are specific to psychosis compared to young adolescents with attention deficit hyperactivity disorder (ADHD).

METHOD

MMN and P3a amplitude were assessed in young adolescents (age 12-17 years) with either FEP (N = 27) or ADHD (N = 28) and age- and gender-matched healthy controls (N = 43). The MMN paradigm consisted of a four-tone auditory oddball task with deviant stimuli based on frequency, duration and their combination.

RESULTS

Significantly less MMN was found in patients with psychosis compared to healthy controls in response to frequency and duration deviants. MMN amplitudes in the group of patients with ADHD were not significantly different from patients with psychosis or healthy controls. No significant group differences were found on P3a amplitude.

CONCLUSION

Young adolescents with FEP showed impaired MMN compared to healthy controls while intermediate and overlapping levels of MMN were observed in adolescents with ADHD. The findings suggest that young FEP patients already exhibit pre-attentive deficits that are characteristic of schizophrenia albeit expressed on a continuum shared with other neuropsychiatric disorders.

Executive function and neural activation in adults with β-thalassemia major: an event-related potentials study

In recent years, there has been growing interest in understanding the involvement of the nervous system and neurological complications in β-thalassemia major (β-TM). Several reports have demonstrated β-TM-related neurological abnormalities, and these have been postulated to be responsible for impaired cognitive and neuropsychological functioning. We investigated neural correlates of cognitive function in adults with β-TM and healthy controls using scalp-recorded event-related potentials (ERPs). To date, there have been no ERP studies in β-TM adult patients. We identified ERP correlates of executive function by using a complex task-switching paradigm in which participants have to quickly and effectively switch between two different task sets. The results indicated poorer cognitive performance of β-TM patients, resulting in overall higher error rates, longer response times, and increased switch costs compared with controls. Hemoglobin levels were negatively correlated with error rates and response times. Electrophysiological results indicated significant alterations in peak amplitudes of the ERP components P1, N1, and P2 in β-TM patients relative to controls. P2 amplitude correlated with hemoglobin levels. This novel investigation of executive function and related brain mechanisms and dynamics in adults with β-TM underscores the usefulness of ERP methodology as a sensitive measure for the study of neurocognitive processes in β-TM.

Possible Effects of Copper and Ceruloplasmin Levels on Auditory Event Potentials in Boys with Attention Deficit Hyperactivity Disorder

INTRODUCTION

The aims of the present study were to investigate the relationship between levels of plasma copper (Cu) and ceruloplasmin (Cp) and amplitudes and latencies of P1, N2, and P3 in the parietal and frontal areas of children with attention deficit hyperactivity disorder (ADHD) as well as to compare these Cu levels and event-related potentials (ERPs) indices in controls.

METHODS

Boys (n=41) with ADHD were divided into two subgroups according to a median split of plasma Cu and Cp levels, separately. ERP indices from the parietal and frontal regions were recorded in children with ADHD and 24 normal boys (control group) using an auditory oddball paradigm.

RESULTS

Parietal P3 latency was significantly longer, and parietal P3 amplitude, frontal P3 amplitude, and frontal N2 amplitudes were smaller in children with ADHD than in controls (all p values <0.017). Parietal P1 and frontal P1 latencies were significantly shorter in the higher Cu group than in the lower Cu group (both p values <0.017). Decreased latency of parietal P1 was dependent on plasma levels of Cu (p<0.05). Frontal N2 and parietal N2 amplitudes were significantly lower in the ADHD group with lower Cp levels than in the ADHD group with higher Cp levels (both p values <0.017). Decreased frontal N2 and parietal N2 amplitudes were dependent on plasma levels of Cp (both p values <0.05).

CONCLUSION

Plasma Cu and Cp levels may have an effect on ERPs in ADHD, thus indicating the existence of effects on information processing. Cu levels may have a negative effect on the neuronal encoding of sound, whereas Cp levels may have a positive effect on the processes of cognitive control, conflict monitoring, and stimulus discrimination in children with ADHD.

The Influence of Gestational Diabetes on Neurodevelopment of Children in the First Two Years of Life: A Prospective Study

OBJECTIVE

Analyze the relation of gestational diabetes and maternal blood glucose levels to early cognitive functions in the first two years of life.

METHODS

In a prospective Singaporean birth cohort study, pregnant women were screened for gestational diabetes at 26-28 weeks gestation using a 75-g oral glucose tolerance test. Four hundred and seventy three children (n = 74 and n = 399 born to mothers with and without gestational diabetes respectively) underwent neurocognitive assessments at 6, 18, and/or 24 month, including electrophysiology during an attentional task and behavioral measures of attention, memory and cognition.

RESULTS

Gestational diabetes is related to left hemisphere EPmax amplitude differences (oddball versus standard) at both six (P = 0.039) and eighteen months (P = 0.039), with mean amplitudes suggesting offspring of mothers with gestational diabetes exhibit greater neuronal activity to standard stimuli and less to oddball stimuli. Associations between 2-hour maternal glucose levels and the difference in EPmax amplitude were marginal at 6 months [adjusted β = -0.19 (95% CI: -0.42 to +0.04) μV, P = 0.100] and significant at 18 months [adjusted β = -0.27 (95% CI: -0.49 to -0.06) μV, P = 0.014], and the EPmax amplitude difference (oddball-standard) associated with the Bayley Scales of Infant and toddler Development-III cognitive score at 24 months [β = 0.598 (95% CI: 0.158 to 1.038), P = 0.008].

CONCLUSION

Gestational diabetes and maternal blood glucose levels are associated with offspring neuronal activity during an attentional task at both six and eighteen months. Such electrophysiological differences are likely functionally important, having been previously linked to attention problems later in life.

Event-Related Potentials and Emotion Processing in Child Psychopathology

In recent years there has been increasing interest in the neural mechanisms underlying altered emotional processes in children and adolescents with psychopathology. This review provides a brief overview of the most up-to-date findings in the field of event-related potentials (ERPs) to facial and vocal emotional expressions in the most common child psychopathological conditions. In regards to externalizing behavior (i.e., ADHD, CD), ERP studies show enhanced early components to anger, reflecting enhanced sensory processing, followed by reductions in later components to anger, reflecting reduced cognitive-evaluative processing. In regards to internalizing behavior, research supports models of increased processing of threat stimuli especially at later more elaborate and effortful stages. Finally, in autism spectrum disorders abnormalities have been observed at early visual-perceptual stages of processing. An affective neuroscience framework for understanding child psychopathology can be valuable in elucidating underlying mechanisms and inform preventive intervention.

Performance Monitoring in Medication-Naïve Children with Tourette Syndrome

Background: Tourette syndrome (TS) is a childhood-onset neurodevelopmental disorder and its impact on cognitive development needs further study. Evidence from neuropsychological, neuroimaging and electrophysiological studies suggests that the decline in tic severity and the ability to suppress tics relate to the development of self-regulatory functions in late childhood and adolescence. Hence, tasks measuring performance monitoring might provide insight into the regulation of tics in children with TS.

Method: Twenty-five children with TS, including 14 with comorbid Attention-deficit/ hyperactivity disorder (ADHD), 39 children with ADHD and 35 typically developing children aged 8–12 years were tested with a modified Eriksen-Flanker task during a 34-channel electroencephalography (EEG) recording. Task performance, as well as stimulus-locked and response-locked event-related potentials (ERP) were analyzed and compared across groups.

Results: Participants did not differ in their behavioral performance. Children with TS showed higher amplitudes of an early P3 component of the stimulus-locked ERPs in ensemble averages and in separate trial outcomes, suggesting heightened orienting and/or attention during stimulus evaluation. In response-locked averages, children with TS had a slightly higher positive complex before the motor response, likely also reflecting a late P3. Groups did not differ in post-response components, particularly in the error-related negativity (ERN) and error-related positivity (Pe).

Conclusions: These findings suggest that children with TS may employ additional attentional resources as a compensatory mechanism to maintain equal behavioral performance.

The Impact of a Cognitive-Behavioral Therapy on Event-Related Potentials in Patients with Tic Disorders or Body-Focused Repetitive Behaviors

CONTEXT

Tic disorders (TD) are characterized by the presence of non-voluntary contractions of functionally related groups of skeletal muscles in one or multiple body parts. Patients with body-focused repetitive behaviors (BFRB) present frequent and repetitive behaviors, such as nail biting or hair pulling. TD and BFRB can be treated with a cognitive-behavioral therapy (CBT) that regulates the excessive amount of sensorimotor activation and muscular tension. Our CBT, which is called the cognitive-psychophysiological (CoPs) model, targets motor execution and inhibition, and it was reported to modify brain activity in TD. However, psychophysiological effects of therapy are still poorly understood in TD and BFRB patients. Our goals were to compare the event-related potentials (ERP) of TD and BFRB patients to control participants and to investigate the effects of the CoPs therapy on the P200, N200, and P300 components during a motor and a non-motor oddball task.

METHOD

Event-related potential components were compared in 26 TD patients, 27 BFRB patients, and 27 control participants. ERP were obtained from 63 EEG electrodes during two oddball tasks. In the non-motor task, participants had to count rare stimuli. In the motor task, participants had to respond with a left and right button press for rare and frequent stimuli, respectively. ERP measures were recorded before and after therapy in both patient groups.

RESULTS

CoPs therapy improved symptoms similarly in both clinical groups. Before therapy, TD and BFRB patients had reduced P300 oddball effect during the non-motor task, in comparison with controls participants. An increase in the P300 oddball effect was observed posttherapy. This increase was distributed over the whole cortex in BFRB patients, but localized in the parietal area in TD patients.

DISCUSSION

These results suggest a modification of neural processes following CoPs therapy in TD and BFRB patients. CoPs therapy seems to impact patients' attentional processes and context updating capacities in working memory (i.e., P300 component). Our results are consistent with a possible role of the prefrontal cortex and corpus callosum in mediating interhemispheric interference in TD.

Electrocortical Dynamics in Children with a Language-Learning Impairment Before and After Audiovisual Training

Detecting and discriminating subtle and rapid sound changes in the speech environment is a fundamental prerequisite of language processing, and deficits in this ability have frequently been observed in individuals with language-learning impairments (LLI). One approach to studying associations between dysfunctional auditory dynamics and LLI, is to implement a training protocol tapping into this potential while quantifying pre- and post-intervention status. Event-related potentials (ERPs) are highly sensitive to the brain correlates of these dynamic changes and are therefore ideally suited for examining hypotheses regarding dysfunctional auditory processes. In this study, ERP measurements to rapid tone sequences (standard and deviant tone pairs) along with behavioral language testing were performed in 6- to 9-year-old LLI children (n = 21) before and after audiovisual training. A non-treatment group of children with typical language development (n = 12) was also assessed twice at a comparable time interval. The results indicated that the LLI group exhibited considerable gains on standardized measures of language. In terms of ERPs, we found evidence of changes in the LLI group specifically at the level of the P2 component, later than 250 ms after the onset of the second stimulus in the deviant tone pair. These changes suggested enhanced discrimination of deviant from standard tone sequences in widespread cortices, in LLI children after training.

Avaliação eletrofisiológica do sistema auditivo em indivíduos com gagueira desenvolvimental persistente

RESUMO: Objetivo: descrever os achados dos exames eletrofisiológicos de indivíduos com gagueira e comparar com indivíduos com desenvolvimento típico. Métodos: participaram desta pesquisa 34 indivíduos, de ambos aos gêneros, com idade entre 7 e 31 anos. O grupo pesquisa foi constituído por 13 crianças (G1a) e 4 adultos (G1b) diagnosticadas com gagueira e o grupo controle por 13 crianças (G2a) com bom desempenho acadêmico e 4 adultos (G2b) com desenvolvimento típico. Foi realizada a avaliação dos potenciais auditivos, na varredura de frequência e de duração. Resultado: quando comparados os grupos de crianças gagas e controle, foi observado que as crianças gagas apresentaram na varredura de frequência, aumento da latência dos componentes P2, N2 em Cz na orelha direita e N2 e P3 em Fz na orelha esquerda, e diferença na amplitude de P2 e P3 em Cz na orelha direita. Na varredura de duração, houve redução da amplitude dos componentes N2 em Cz e P3 em Fz na orelha direita. Já no grupo de adultos gagos, observou-se na varredura de frequência, aumento da latência no componente P3 em Cz e Fz na orelha direita e amplitude reduzida no P3 em Cz na orelha esquerda, e na varredura de duração, aumento de latência de N2 e P3 em Cz na orelha direita e N2 em Cz na orelha esquerda, quando comparados ao grupo controle. Conclusão: há diferenças entre os exames eletrofisiológicos de indivíduos com gagueira comparados aqueles com desenvolvimento típico. No entanto, novos estudos neste âmbito ainda são necessários para que os achados aqui apresentados possam ser confirmados.

Resting EEG and ERPs findings in methadone-substituted opiate users: a review

Methadone has been used to treat opiate dependence since the mid-1960s. Despite its clinical effectiveness there is evidence from neuropsychological studies demonstrating that its long-term use might have negative effects on cognition. Nevertheless, it remains uncertain whether the observed cognitive impairments in patients undertaking methadone maintenance treatment (MMT) are solely attributable to the pharmacological effects of methadone, as suggested by some researchers. Determining the effects of MMT on neuropsychological function using electroencephalography (EEG) combined with event-related potentials (ERP) has been used infrequently. However EEG and ERP provide a means of closely examining information processing to determine whether MMT induces any deficits. The purpose of this review was to investigate whether psychophysiological evidence supports cognitive impairment in association with MMT by focusing on research using EEG and ERPs. The findings of EEG studies to date appear not support the notion that cognitive impairments are attributable to the specific pharmacological effects of methadone suggested by some neuropsychological studies. However, due to the methodological deficits and limited number of the studies, any conclusion based on the findings of the existing EEG studies should be avoided.

A meta-analysis of mismatch negativity in children with attention deficit-hyperactivity disorders

Mismatch negativity (MMN) is an optimal neurophysiological signal to assess the integrity of auditory sensory memory and involuntary attention switch. The generation of MMN is independent of overt behavioral requirements, concentration or motivation, and thus serves as a suitable tool to study the perceptual function in children with attention deficit-hyperactivity disorders (ADHD). It remains unclear whether ADHD children showed altered MMN responses. Therefore we performed a meta-analysis of peer-reviewed MMN studies that had targeted both typically developed and ADHD children to examine the pooled effect size. The published articles between 1990 and 2014 were searched in PubMed, Medline, Cochrane, and CINAHL. The mean effect size and a 95% confidence interval (CI) were estimated. Six studies, consisting of 10 individual investigations, were included in the final analysis. A significant effect size of 0.28 was found (p=0.028, 95% CI at 0.03-0.53). These results were also free from publication bias or heterogeneity. In conclusion, our meta-analysis results suggest ADHD children demonstrated a reduced MMN amplitude compared to healthy controls.

Auditory event-related potentials in methadone substituted opiate users

The effects of methadone maintenance treatment (MMT) on neurophysiological function are unclear. Using an auditory oddball paradigm, event-related potential (ERP) amplitudes and latencies were measured in 32 patients undertaking MMT, 17 opiate users who were addicted but not receiving substitution treatment and 25 healthy control subjects. Compared with healthy control subjects, the MMT and opiate user groups showed an increased P200 amplitude in response to target stimuli. The opiate user group also exhibited a decreased amplitude and an increased latency of N200, and a greater number of task-related errors than either healthy control subjects or patients undertaking MMT. There were no significant group differences in the P300 amplitude. However, it is noteworthy that the frontal P300 amplitude of the MMT group was greater than that of opiate users or healthy controls. Our findings suggest that altered sensory information processing associated with a history of opiate use remains in patients undertaking MMT. However, there are less marked ERP abnormalities in those receiving MMT than in active opiate users. The deficits in information processing associated with illicit opiate use are likely to be reduced during MMT.

Attention deficits revealed by passive auditory change detection for pure tones and lexical tones in ADHD children

Inattention (IA) has been a major problem in children with attention deficit/hyperactivity disorder (ADHD), accounting for their behavioral and cognitive dysfunctions. However, there are at least three processing steps underlying attentional control for auditory change detection, namely pre-attentive change detection, involuntary attention orienting, and attention reorienting for further evaluation. This study aimed to examine whether children with ADHD would show deficits in any of these subcomponents by using mismatch negativity (MMN), P3a, and late discriminative negativity (LDN) as event-related potential (ERP) markers, under the passive auditory oddball paradigm. Two types of stimuli-pure tones and Mandarin lexical tones-were used to examine if the deficits were general across linguistic and non-linguistic domains. Participants included 15 native Mandarin-speaking children with ADHD and 16 age-matched controls (across groups, age ranged between 6 and 15 years). Two passive auditory oddball paradigms (lexical tones and pure tones) were applied. The pure tone oddball paradigm included a standard stimulus (1000 Hz, 80%) and two deviant stimuli (1015 and 1090 Hz, 10% each). The Mandarin lexical tone oddball paradigm's standard stimulus was /yi3/ (80%) and two deviant stimuli were /yi1/ and /yi2/ (10% each). The results showed no MMN difference, but did show attenuated P3a and enhanced LDN to the large deviants for both pure and lexical tone changes in the ADHD group. Correlation analysis showed that children with higher ADHD tendency, as indexed by parents' and teachers' ratings on ADHD symptoms, showed less positive P3a amplitudes when responding to large lexical tone deviants. Thus, children with ADHD showed impaired auditory change detection for both pure tones and lexical tones in both involuntary attention switching, and attention reorienting for further evaluation. These ERP markers may therefore be used for the evaluation of anti-ADHD drugs that aim to alleviate these dysfunctions.

Electrophysiology of facilitation priming in obsessive-compulsive and panic disorders

OBJECTIVE

Repeated experience with stimuli often primes faster, more efficient neuronal and behavioural responses. Exaggerated repetition priming effects have previously been reported in obsessive-compulsive disorder (OCD), however little is known of their underlying neurobiology or disorder-specificity, hence we investigated these factors.

METHODS

We examined event-related potentials (ERPs) and behaviour while participants with OCD, panic disorder and healthy controls (20 per group) performed a Go/NoGo task which manipulated target repetition sequences.

RESULTS

Both clinical groups showed stronger reaction time (RT) priming than HCs, which in OCD was greater in a checking, than washing, subgroup. Both clinical groups had similar RT deficits and ERP anomalies across several components, which correlated with psychopathology and RT priming. In OCD alone, N1 latency tended to increase to repeated stimuli, correlated with O-C symptoms, whereas it decreased in other groups. OCD-checkers had smaller target P2 amplitude than all other groups.

CONCLUSIONS

Enhanced neural priming is not unique to OCD and may contribute to salient sensory-cognitive experiences in anxiety generally. These effects are related to symptom severity and occur to neutral stimuli and in the context of overall RT impairment, suggesting they may be clinically relevant and pervasive. The results indicate overlapping information-processing and neurobiological factors across disorders, with indications of OCD-specific trends and subgroup differences.

SIGNIFICANCE

This first electrophysiological investigation of OCD priming in OCD to include anxious controls and OCD subgroups allows for differentiation between overlapping and OCD-specific phenomena, to advance neurobiological models of OCD.

[Differential effects of attention deficit/hyperactivity disorder subtypes in event-related potentials]

BACKGROUND

To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD.

METHODS

A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons.

RESULTS

ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects.

CONCLUSIONS

The results show differences in the event-related potentials between combined and inattentive ADHD subjects.

Atypical neural responses to vocal anger in attention-deficit/hyperactivity disorder

BACKGROUND

Deficits in facial emotion processing, reported in attention-deficit/hyperactivity disorder (ADHD), have been linked to both early perceptual and later attentional components of event-related potentials (ERPs). However, the neural underpinnings of vocal emotion processing deficits in ADHD have yet to be characterised. Here, we report the first ERP study of vocal affective prosody processing in ADHD.

METHODS

Event-related potentials of 6-11-year-old children with ADHD (n = 25) and typically developing controls (n = 25) were recorded as they completed a task measuring recognition of vocal prosodic stimuli (angry, happy and neutral). Audiometric assessments were conducted to screen for hearing impairments.

RESULTS

Children with ADHD were less accurate than controls at recognising vocal anger. Relative to controls, they displayed enhanced N100 and attenuated P300 components to vocal anger. The P300 effect was reduced, but remained significant, after controlling for N100 effects by rebaselining. Only the N100 effect was significant when children with ADHD and comorbid conduct disorder (n = 10) were excluded.

CONCLUSION

This study provides the first evidence linking ADHD to atypical neural activity during the early perceptual stages of vocal anger processing. These effects may reflect preattentive hyper-vigilance to vocal anger in ADHD.

Event related potentials study of aberrations in voice control mechanisms in adults with attention deficit hyperactivity disorder

OBJECTIVE

The present study was designed to test for neural signs of impulsivity related to voice motor control in young adults with ADHD using EEG recordings in a voice pitch perturbation paradigm.

METHODS

Two age-matched groups of young adults were presented with brief pitch shifts of auditory feedback during vocalization. Compensatory behavioral and corresponding bioelectrical brain responses were elicited by the pitch-shifted voice feedback.

RESULTS

The analysis of bioelectrical responses showed that the ADHD group had shorter peak latency and onset time of motor-related bioelectrical brain responses as compared to the controls.

CONCLUSIONS

These results were interpreted to suggest differences in executive functions between ADHD and control participants.

SIGNIFICANCE

We hypothesize that more rapid motor-related bioelectrical responses found in the present study may be a manifestation of impulsiveness in adults with ADHD at the involuntary level of voice control.

How specific are inhibitory deficits to obsessive-compulsive disorder? A neurophysiological comparison with panic disorder

OBJECTIVE

Impaired inhibition may perpetuate repetitive symptoms in obsessive-compulsive disorder (OCD), however OCD-specific deficits have yet to be established. We investigated neural correlates of inhibition in OCD vs. healthy and anxious controls.

METHODS

ERPs and reaction times (RTs) were compared between participants with OCD (n=20), panic disorder (PD; n=20) and healthy controls (HCs; n=20) during an adapted Go/NoGo task, which manipulated inhibitory difficulty.

RESULTS

A classic P3 NoGo anteriorisation effect occurred across groups. Both clinical groups showed RT impairment, and similar topographical anomalies of several (P2, N2 and P3) ERP components. Notably, both clinical groups lacked the strong frontally maximal N2 component topography seen in the HCs, across stimuli. Additionally, with increasing inhibitory difficulty, N2 latency increased in HCs but not in the clinical groups.

CONCLUSIONS

Unexpectedly, ERP and behavioural anomalies during inhibition in OCD were not qualitatively different to those in PD, but were generally more severe. Common general and inhibitory deficits may underlie intrusive mental phenomena in both conditions.

SIGNIFICANCE

This first ERP response inhibition study in OCD to include anxious controls disconfirmed hypotheses regarding OCD-specific inhibitory deficits, indicating the importance of comparing OCD to other conditions, to evaluate neurobiological models.

Automatic processing of duration in children with attention-deficit/hyperactivity disorder

Individuals with attention-deficit/hyperactivity disorder (ADHD) often exhibit deficits in processing information about time. Most studies, however, have required participants to perform active tasks and consequently it is unclear if performance deficits are due to impaired processing of temporal information, attentional deficits, or to impairments at a later stage of decision-making. This study used mismatch negativity (MMN) to examine automatic processing of temporal information in children with ADHD. The sample consisted of 11 children with typical development (8 boys; mean age/SD = 9.3/0.6 years) and 12 with ADHD (10 boys; mean age/SD = 8.9/0.8 years). Using the MMN paradigm, responses to standards and four deviants (hard/easy frequency, hard/easy duration) were elicited during the same sequence. The children's ability to actively discriminate each deviant was also assessed. Both groups exhibited MMNs to all deviants suggesting successful automatic discrimination. Furthermore, amplitude and latency measures were roughly comparable across groups. No group differences were seen on the active discrimination task, but performance was worse for duration than for frequency deviants. These results suggest that children with ADHD are able to automatically process temporal information, so deficits reported in active discrimination paradigms are likely due to deficits in subjective perception or usage of temporal information.

Magnetoencephalography reveals altered auditory information processing in youth with obsessive-compulsive disorder

Patients with obsessive-compulsive disorder (OCD) often report sensory intolerances which may lead to significant functional impairment. This study used auditory evoked fields (AEFs) to address the question of whether neural correlates of sensory auditory information processing differ in youth with OCD compared with healthy comparison subjects (HCS). AEFs, recorded with a whole head 275-channel magnetoencephalography system, were elicited in response to binaural auditory stimuli from 10 pediatric subjects with OCD (ages 8-13, mean 11 years, 6 males) and 10 age- and gender-matched HCS. Three major neuromagnetic responses were studied: M70 (60-80 ms), M100 (90-120 ms), and M150 (130-190 ms). When compared with HCS, subjects with OCD demonstrated delayed latency of the M100 response. In subjects with OCD the amplitude of the M100 and M150 responses was significantly greater in the right hemisphere compared with the left hemisphere. Current results suggest that when compared with HCS, subjects with OCD have altered auditory information processing, evident from the delayed latency of the M100 response, which is thought to be associated with the encoding of physical stimulus characteristics. Interhemispheric asymmetry with increased M100 and M150 amplitudes over the right hemisphere compared with the left hemisphere was found in young OCD subjects. These results should be interpreted with caution due to the high variability rate of responses in both HCS and OCD subjects, as well as the possible effect of medication in OCD subjects.

Excitatory versus inhibitory impairments in insomnia patients: an ERP study

According to the neurocognitive perspective on insomnia, conditioned arousal results in impairment of information processing, as such interfering with normal sleep processes. In the present study, evening event-related potentials N100 and P200 were evaluated to assess hyperarousal in patients with insomnia and controls. 13 patients (mean age = 40.8) with polysomnographically verified sleep disruptions and 11 good sleepers (mean age = 45.4) were included. An auditory oddball paradigm was administered the evening of the polysomnography. N100 and P200 mean amplitudes and peak latencies at Fz and Cz were analyzed as a measure of respectively general arousability and inhibition of information processing. Patients experiencing insomnia were characterized by decreased P200 amplitudes compared to good sleepers. No significant differences were found for N100 amplitudes and latencies of both ERP waves. These results suggest that this group of patients with objectified insomnia is characterized by an arousal impairment. However, there was no evidence of hyperarousal, considering the normal N100 amplitudes. On the other hand, the inhibition of information processing was distorted. As such, the impairment of de-arousal or de-activation in insomnia is put forward as an additional factor within the arousal model.

Abnormal centroparietal ERP response in predominantly medication-naive adolescent boys with ADHD during both response inhibition and execution

Abnormal event-related potential (ERP) responses have been reported in children and adolescents with attention deficit hyperactivity disorder (ADHD) and a medication history compared with in healthy controls during tasks of response control and conflict inhibition. This study reports neurophysiologic correlates of a task dependent on these cognitive functions in a large, predominantly medication naive, group of adolescents with ADHD compared with that in healthy age- and intelligence quotient (IQ)-matched controls using area-under-the-curve (AUC) analysis. Fifty-four adolescents with ADHD and 55 healthy comparisons completed a hybrid conflict and response inhibition Go/NoGo ERP task. The performance data showed that children with ADHD compared with controls had deficits in both the inhibitory measures (higher commission errors) and the Go process of the task (slower reaction times and enhanced omission errors). The ERP data showed significant impairments in brain function in the ADHD relative to the control group for late, endogenous ERPs (N2, P3a, and P3b), whereas no group differences were found for the earlier P200. All findings remained when a minority of children with medication history was excluded. Furthermore, deficits were not specific to the inhibitory processes of the task but were equally observed during the execution functions. Group differences were particularly pronounced over central and centroparietal sites across all time points, presumably reflecting the midline attention system mediated by anterior and posterior cingulate that is important for generic, condition-independent visual-spatial attention and response selection processes. The findings demonstrate that adolescents with ADHD have abnormal ERP responses not only during inhibitory, but also execution-related processes and, furthermore, that these deficits are independent from medication history.

Attention in children with obstructive sleep apnoea: an event-related potentials study

BACKGROUND

Obstructive sleep apnoea (OSA) in children has been causally implicated in neurobehavioural and cognitive dysfunction. Consequently, the American Academy of Paediatrics highlighted the need to study pertinent functional cognitive outcomes before and after treatment. However, neurocognitive function has thus far only been assessed by caregiver-completed questionnaires, which can be labour intensive and time consuming, such that the need for complementary and more objective measures has emerged.

OBJECTIVE

The study aimed to identify electrophysiological correlates of neurocognitive alterations in children with OSA and investigate utility as a predictive tool.

PATIENTS AND METHODS

Twenty-eight children (14 OSA and 14 matched controls) underwent overnight sleep studies and neurocognitive testing, as well as the oddball attention task while event-related potentials (ERPs) were recorded. ERPs were analysed using temporal principal components and source analyses that provided dependent variables for the subsequent repeated measures analysis of variance (ANOVA) and multiple regressions. Time-locked waveforms formed spatial models that localised electrical activity in the brain. ERP differences between groups were then correlated to neurocognitive outcomes.

RESULTS

OSA children exhibited significantly altered ERP patterns of neural activation and impaired neurocognitive performance. Specific ERP variables exhibited accurate predictive ability regarding performance on neurobehavioural measures.

CONCLUSION

Specific ERP events during a single attention task can reliably identify the presence of OSA-associated cognitive dysfunction. Electrophysiological approaches during specific cognitive tasks may serve as simple, complementary, and reliable reporters of cognitive dysfunction associated with OSA in children.