[Cognitive evoked potentials in children: normal and abnormal development]

Auditory-Perceptual and Auditory-Motor Timing Abilities in Children with Developmental Coordination Disorder: A Scoping Review

Developmental coordination disorder (DCD) remains largely underdiagnosed and masked by other co-occurring conditions. The aim of this study was to (1) provide the first review of research regarding auditory-motor timing and synchronization abilities in children with DCD and (2) examine whether reduced motor performance may be associated with difficulties in auditory perceptual timing. The scoping review was carried out across five major databases (MEDLINE, Embase, PsycINFO, CINAHL, and Scopus) in accordance with the PRISMA-ScR guidelines. Studies were screened by two independent reviewers against the inclusion criteria, without publication date restrictions. From an initial return of 1673 records, 16 articles were included in the final review and synthesized based on the timing modality studied (i.e., auditory-perceptual, motor, or auditory-motor). Results suggest that children with DCD have difficulties with rhythmic movements both with and without external auditory cues and further indicate that variability in and slowness of motor response are key characteristics of DCD, regardless of the experimental task. Importantly, our review highlights a significant gap in the literature regarding auditory perceptual abilities in DCD. In addition to testing auditory perception, future studies should compare the performance of children with DCD on paced and unpaced tasks to determine whether auditory stimuli contribute to a more or less stable performance. This knowledge may inform future therapeutic interventions.

Auditory ERPs in Children with Developmental Coordination Disorder

The present study aims to investigate and compare the auditory attention performance of children with developmental coordination disorder (DCD) and normally developing children (NDC) using cognitive evoked potentials (ERPs) in passive conditions. ERPs data showed that children with DCD have less ability to detect small physical differences between acoustic stimuli (no MMN response in DCD children) and have a reduced attentional engagement and stimulus evaluation of salient stimuli (a reduction of P3 amplitude in DCD children). The results of our study suggest that children with DCD do not only suffer from a visuospatial attention deficit as previous studies reported but also have auditory attention deficit.

Renewal of the neurophysiology of language: functional neuroimaging

Functional neuroimaging methods have reached maturity. It is now possible to start to build the foundations of a physiology of language. The remarkable number of neuroimaging studies performed so far illustrates the potential of this approach, which complements the classical knowledge accumulated on aphasia. Here we attempt to characterize the impact of the functional neuroimaging revolution on our understanding of language. Although today considered as neuroimaging techniques, we refer less to electroencephalography and magnetoencephalography studies than to positron emission tomography and functional magnetic resonance imaging studies, which deal more directly with the question of localization and functional neuroanatomy. This review is structured in three parts. 1) Because of their rapid evolution, we address technical and methodological issues to provide an overview of current procedures and sketch out future perspectives. 2) We review a set of significant results acquired in normal adults (the core of functional imaging studies) to provide an overview of language mechanisms in the "standard" brain. Single-word processing is considered in relation to input modalities (visual and auditory input), output modalities (speech and written output), and the involvement of "central" semantic processes before sentence processing and nonstandard language (illiteracy, multilingualism, and sensory deficits) are addressed. 3) We address the influence of plasticity on physiological functions in relation to its main contexts of appearance, i.e., development and brain lesions, to show how functional imaging can allow fine-grained approaches to adaptation, the fundamental property of the brain. In closing, we consider future developments for language research using functional imaging.

Frontal, temporal and lateralized brain function in children with attention-deficit hyperactivity disorder: a psychophysiological and neuropsychological viewpoint on development

This article considers deficits in the selective aspects of perception underlying symptoms of impaired attention and impulsivity in children with attention-deficit hyperactivity syndrome (ADHD) in terms of frontal and temporal lobe function and cerebral asymmetry. Tomographic studies suggest a disturbed fronto-striatal function, but have neglected limbic contributions under activating conditions and are equivocal on the nature of apparent lateralized differences. Neuropsychological and psychophysiological studies suggest that early and late stages of information processing are affected in both the frontal and temporal lobes and imply impaired intercortical dialog. Given the evidence for a normal specialization in global processing in the right and the processing of details in the left hemisphere, the lateralized impairment may progress from situational ADHD (impaired selective aspects of perception on the right) to pervasive ADHD (additional impairment in decision-making on the left). Accordingly some ADHD children may experience an early negative neurodevelopmental influence that only appears as the brain region matures while others show a delayed development of CNS function.

Event-related potential negative shift in sons of polysubstance- and alcohol-use disorder fathers

Previous research has considered event-related potentials (ERPs) in relation to liability for alcohol and other substance use. This study explored ERPs in preadolescent boys at elevated risk for substance use due to paternal history of substance abuse or dependence. Sons (age 10-12) of fathers with an alcohol-use disorder (ALC, n = 29) were matched by age, IQ, education and parental alcohol use with sons of fathers with a polysubstance abuse or dependence diagnosis (POLY, n = 37). These two groups were matched with a low-risk comparison group (LOW, n = 29) of boys whose fathers had no substance-use disorder diagnosis. No boy in the study met criteria for a substance-use disorder. ERPs were collected from midline (Fz, Cz, Pz) and parietal (P3, P4) electrode leads during an auditory oddball task. ERPs of boys from the ALC and POLY groups showed a slow negative shift prominent at Cz and Pz. This negative shift, evident by 100 ms post-stimulus and lasting for the duration of the 1000-ms recording period, overlapped temporally with N1, N2 and P3 amplitude differences distinguishing the ALC and POLY groups from the LOW group. The ALC and POLY groups differed from each other in N2 amplitude at Cz, which was larger for ALC subjects. These findings offer a possible alternative explanation for previously observed amplitude anomalies noted in children at risk for substance-use disorders and suggest new avenues of inquiry.