Pro- and antisaccades in children elicited by visual and acoustic targets - does modality matter?

Background: Children are able to inhibit a prepotent reaction to suddenly arising visual stimuli, although this skill is not yet as pronounced as it is in adulthood. However, up to now the inhibition mechanism to acoustic stimuli has been scarcely investigated

Methods: Reflexive (prosaccade) and inhibitory (antisaccade) responses to visual and acoustic targets were examined with an eye tracker system in 31 children between seven and twelve years of age using a gap-overlap task and two target eccentricities.

Results: Acoustically cued saccades had longer reaction times than visually cued saccades.

Reduced mismatch negativity and increased variability of brain activity in schizophrenia.

Objectives: Schizophrenia patients commonly exhibit smaller amplitudes of mismatch negativity (MMN) than in controls. It remains unclear whether this results from deficient processes indexed by MMN or 'normally' though more variable processing. The present magnetoencephalographic study addressed this question by analyzing intra-individual trial-by-trial variability and MMN amplitude.

Medio-frontal and anterior temporal abnormalities in children with attention deficit hyperactivity disorder (ADHD) during an acoustic antisaccade task as revealed by electro-cortical source reconstruction.

Background: Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent disorders in children and adolescence. Impulsivity is one of three core symptoms and likely associated with inhibition difficulties. To date the neural correlate of the antisaccade task, a test of response inhibition, has not been studied in children with (or without) ADHD.

Hippocampal activity during the transverse patterning task declines with cognitive competence but not with age.

Background: The hippocampus is a brain region that is particularly affected by age-related morphological changes. It is generally assumed that a loss in hippocampal volume results in functional deficits that contribute to age-related cognitive decline. In a combined cross-sectional behavioural and magnetoencephalography (MEG) study we investigated whether hippocampal-associated neural current flow during a transverse patterning task - which requires learning relational associations between stimuli - correlates with age and whether it is modulated by cognitive competence.

Localization of the magnetic equivalent of the ERN and induced oscillatory brain activity.

It has been found in numerous electroencephalographic (EEG) studies that a negative potential arises following an erroneous response (so-called Error-Related Negativity, ERN). This typical component of the EEG has, however, proven more difficult to identify when transferring analogous paradigms to magnetoencephalography (MEG). The aim of this study was to devise and apply a paradigm to elicit erroneous responses and using MEG to measure both the error-related evoked brain activity (mERN) as well as accompanying induced oscillatory activity.

Concurrent sound segregation based on inharmonicity and onset asynchrony.

To explore the neural processes underlying concurrent sound segregation, auditory evoked fields (AEFs) were measured using magnetoencephalography (MEG). To induce the segregation of two auditory objects we manipulated harmonicity and onset synchrony. Participants were presented with complex sounds with (i) all harmonics in-tune (ii) the third harmonic mistuned by 8% of its original value (iii) the onset of the third harmonic delayed by 160 ms compared to the other harmonics.