EEG used to be a first-line method of diagnosis for tumors, stroke and other focal brain disorders, but this use has decreased with the advent of high-resolution anatomical imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT). It is also used to diagnose sleep disorders, depth of anesthesia, coma, encephalopathies, and brain death. The latter analyses the type of neural oscillations (popularly called "brain waves") that can be observed in EEG signals in the frequency domain.ĮEG is most often used to diagnose epilepsy, which causes abnormalities in EEG readings.
The former investigates potential fluctuations time locked to an event, such as 'stimulus onset' or 'button press'. Diagnostic applications generally focus either on event-related potentials or on the spectral content of EEG. Clinically, EEG refers to the recording of the brain's spontaneous electrical activity over a period of time, as recorded from multiple electrodes placed on the scalp. Electrocorticography, involving invasive electrodes, is sometimes called intracranial EEG.ĮEG measures voltage fluctuations resulting from ionic current within the neurons of the brain. It is typically non-invasive, with the electrodes placed along the scalp. Overall, our findings offer novel supporting evidence implicating alpha oscillations in inhibitory control, as well as their potential role in the homeostatic regulation of cortical excitatory/inhibitory balance.Electroencephalography ( EEG) is a method to record an electrogram of the electrical activity on the scalp that has been shown to represent the macroscopic activity of the surface layer of the brain underneath. reduced commission errors) only in the ADHD group. Importantly, the degree of post-NFB alpha normalization during the Go/NoGo task correlated with individual improvements in motor inhibition (i.e. rebound) in the ADHD group, which restored alpha power towards levels of the normal population. Interestingly, we observed a post-NFB increase in resting-state alpha (i.e. Both groups demonstrated a significant and targeted reduction of alpha power during NFB. Firstly, we found that relative alpha power was attenuated in our ADHD cohort compared to control subjects at baseline and across experimental conditions, suggesting a signature of cortical hyper-activation. Alpha power was compared across conditions and groups, and the effects of NFB were statistically assessed by comparing behavioral and EEG measures pre-to-post NFB. Twenty-five adult ADHD patients and 22 healthy controls underwent a 64-channel EEG-recording at resting-state and during a Go/NoGo task, before and after a 30 min-NFB session designed to reduce (desynchronize) the power of the alpha rhythm. In the present study, we asked adult ADHD patients to self-regulate their own alpha rhythm using neurofeedback (NFB), in order to examine the modulation of alpha oscillations on attentional performance and brain plasticity. In particular, the alpha rhythm (8–12 Hz), known to be modulated during attention, has previously been considered as candidate biomarker for ADHD.
Abnormal patterns of electrical oscillatory activity have been repeatedly described in adult ADHD.
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