Neurofeedback is widely applied as non-pharmacological intervention aimed at reducing symptoms of ADHD, even though efficacy has not been unequivocally established. Neuronal changes during the... Show moreNeurofeedback is widely applied as non-pharmacological intervention aimed at reducing symptoms of ADHD, even though efficacy has not been unequivocally established. Neuronal changes during the neurofeedback intervention that resemble learning can provide crucial evidence for the feasibility and specificity of this intervention. A total of 38 children (aged between 7 and 13 years) with a DSM-IV-TR diagnosis of ADHD, completed on average 29 sessions of theta (4–8 Hz)/beta (13–20 Hz) neurofeedback training. Dependent variables included training-related measures as well as theta and beta power during baseline and training runs for each session. Learning effects were analyzed both within and between sessions. To further specify findings, individual learning curves were explored and correlated with behavioral changes in ADHD symptoms. Over the course of the training, there was a linear increase in participants’ mean training level, highest obtained training level and the number of earned credits (range b = 0.059, −0.750, p < 0.001). Theta remained unchanged over the course of the training, while beta activity increased linearly within training sessions (b = 0.004, 95% CI = [0.0013–0.0067], p = 0.005) and over the course of the intervention (b = 0.0052, 95% CI = [0.0039–0.0065], p < 0.001). In contrast to the group analyses, significant individual learning curves were found for both theta and beta over the course of the intervention in 39 and 53%, respectively. Individual learning curves were not significantly correlated with behavioral changes. This study shows that children with ADHD can gain control over EEG states during neurofeedback, although a lack of behavioral correlates may indicate insufficient transfer to daily functioning, or to confounding reinforcement of electromyographic activity. Clinical Trials Registration: This trial is registered at the US National Institutes of Health (ClinicalTrials.gov, ref. no: NCT01363544); https://clinicaltrials.gov/show/NCT01363544. Show less
One of the most striking features of the brain is that it is modular; it consists of often highly specialized areas. This modular organization requires efficient communication in order to integrate... Show moreOne of the most striking features of the brain is that it is modular; it consists of often highly specialized areas. This modular organization requires efficient communication in order to integrate the information that is represented in distinct brain areas. In my thesis, I studied the neural basis of this communication. With various brain imaging techniques (fMRI, EEG), I found support for the idea that fast communication is omnipresent in the brain and that cognitive control processes can influence this communication. Using a method (neurofeedback) with which subjects were trained to enhance a particular type of brain activity (gamma band activity, or ‘GBA’), I demonstrated that enhanced GBA resulted in an increase of performance on tasks measuring short-term and long-term memory of associated information and fluid intelligence. These findings suggest that GBA underlies the control of associated information, presumably originating from frontal brain regions. Show less
