Behavioral effects of neurofeedback in adolescents with ADHD: a randomized controlled trial.

Neurofeedback has been proposed as a potentially effective intervention for reducing Attention Deficit Hyperactivity Disorder (ADHD) symptoms. However, it remains unclear whether neurofeedback is of additional value to treatment as usual (TAU) for adolescents with clinical ADHD symptoms. Using a multicenter parallel-randomized controlled trial design, adolescents with ADHD symptoms were randomized to receive either a combination of TAU and neurofeedback (NFB + TAU, n = 45) or TAU-only (n = 26). Randomization was computer generated and stratified for age group (ages 12 through 16, 16 through 20, 20 through 24). Neurofeedback treatment consisted of approximately 37 sessions of theta/sensorimotor rhythm (SMR)-training on the vertex (Cz). Primary behavioral outcome measures included the ADHD-rating scale, Youth Self Report, and Child Behavior Checklist all assessed pre- and post-intervention. Behavioral problems decreased equally for both groups with medium to large effect sizes, range of partial η2 = 0.08-0.31, p < 0.05. Hence, the combination of NFB + TAU was not more effective than TAU-only on the behavioral outcome measures. In addition, reported adverse effects were similar for both groups. On behavioral outcome measures, the combination of neurofeedback and TAU was as effective as TAU-only for adolescents with ADHD symptoms. Considering the absence of additional behavioral effects in the current study, in combination with the limited knowledge of specific treatment effects, it is questionable whether theta/SMR neurofeedback for adolescents with ADHD and comorbid disorders in clinical practice should be used. Further research is warranted to investigate possible working mechanisms and (long-term) specific treatment effects of neurofeedback.

Neurocognitive effects of neurofeedback in adolescents with ADHD: a randomized controlled trial.

OBJECTIVE: Neurofeedback aims to reduce symptoms of attention-deficit/hyperactivity disorder (ADHD), mainly attention problems. However, the additional influence of neurofeedback over treatment as usual (TAU) on neurocognitive functioning for adolescents with ADHD remains unclear. METHOD: By using a multicenter parallel randomized controlled trial (RCT) design, male adolescents with a DSM-IV-TR diagnosis of ADHD (mean age = 16.1 years; range, 12-24) were randomized to receive either a combination of TAU and neurofeedback (n = 45) or TAU (n = 26). Randomization was computer generated and stratified by age group (ages 12 through 15, 16 through 20, and 21 through 24 years). The neurofeedback intervention consisted of approximately 37 sessions over a period of 25 weeks of theta/sensorimotor rhythm training on the vertex (Cz). Primary neurocognitive outcomes included performance parameters derived from the D2 Test of Attention, the Digit Span backward, the Stroop Color-Word Test and the Tower of London, all assessed preintervention and postintervention. Data were collected between December 2009 and July 2012. RESULTS: At postintervention, outcomes of attention and/or motor speed were improved, with faster processing times for both intervention conditions and with medium to large effect sizes (range, ηp2 = .08-.54; P values < .023). In both groups, no improvements for higher executive functions were observed. Results might partly resemble practice effects. CONCLUSIONS: Although neurocognitive outcomes improved in all adolescents receiving treatment for ADHD, no additional value for neurofeedback over TAU was observed. Hence, this study does not provide evidence for using theta/sensorimotor rhythm neurofeedback to enhance neurocognitive performance as additional intervention to TAU for adolescents with ADHD symptoms. TRIAL REGISTRATION: Trialregister.nl identifier: 1759.

The time-course of alpha neurofeedback training effects in healthy participants.

The time-course of alpha neurofeedback training (NFT) was investigated in 18 healthy participants who received 15 sessions of training (eyes open), each consisting of three training periods (data are from Van Boxtel et al., 2012). Here we report on the within- and between-session training effects using multilevel analyses. Over sessions, total alpha power (8-12 Hz) increased up to the tenth session, after which low alpha power (8-10 Hz) remained at the same level, while high alpha power (10-12 Hz) decreased. Within each training session, total alpha power increased from the first to the second period, and then decreased again. This decrease, however, was caused by a decrease in high alpha power only; low alpha power remained up to the end of training. These effects are discussed in terms of attention and motivation, and suggest different trainability for low and high alpha power.

A novel self-guided approach to alpha activity training.

Fifty healthy participants took part in a double-blind placebo-controlled study in which they were either given auditory alpha activity (8-12Hz) training (N=18), random beta training (N=12), or no training at all (N=20). A novel wireless electrode system was used for training without instructions, involving water-based electrodes mounted in an audio headset. Training was applied approximately at central electrodes. Post-training measurement using a conventional full-cap EEG system revealed a 10% increase in alpha activity at posterior sites compared to pre-training levels, when using the conventional index of alpha activity and a non-linear regression fit intended to model individual alpha frequency. This statistically significant increase was present only in the group that received the alpha training, and remained evident at a 3 month follow-up session, especially under eyes open conditions where an additional 10% increase was found. In an exit interview, approximately twice as many participants in the alpha training group (53%) mentioned that the training was relaxing, compared to those in either the beta (20%) or no training (21%) control groups. Behavioural measures of stress and relaxation were indicative of effects of alpha activity training but failed to reach statistical significance. These results are discussed in terms of a lack of statistical power. Overall, results suggest that self-guided alpha activity training using this novel system is feasible and represents a step forward in the ease of instrumental conditioning of brain rhythms.

How does a short history of spinal cord injury affect movement-related brain potentials?

Brain plasticity following spinal cord injury (SCI) has been studied by a wide range of neurofunctional techniques, which tend to have low temporal resolution or overlook cognitive preparatory processes. This study tried to overcome both limitations by recording the movement-related brain potentials using an experimental task somewhat similar to the contingent negative variation paradigm. The aim was to look for amplitude or topographic distribution changes at an early stage of the SCI. Hence, the brain electrical activity of patients who had a clinical history of less than 6 months of paraplegia was recorded and compared with that of two groups of healthy volunteers. None of the patients was able to move their toes, but they were asked to prepare to carry out this movement and to try to execute it in the same way as one of the control groups. The other control group was instructed to prepare to conduct the same movement but not to execute it. Results did not show significant differences in the readiness potential between patients with paraplegia and both controls. However, the readiness potential topography observed in patients was more similar to that of healthy participants who conducted the movement, whereas a greater similarity was found in the motor potential between patients and healthy participants who did not carry out the movement. These findings suggest that neurofunctional changes that take place in the brain after a SCI may be shown earlier by the motor potential than by the readiness potential.

What happens to the readiness potential when the movement is not executed?

The purpose of this study was to investigate and compare the movement-related brain potentials recorded from two groups of right-handed male study participants. One of the groups prepared for and conducted repetitive toe movements while the other prepared to carry out the same type of movement but finally did not execute it. The readiness potential, premotion positivity, motor potential and reafferent potential were recorded from 20 electroencephalogram electrodes. The most salient result was the greater readiness potential amplitude discovered in participants who ended up carrying out the movement, which indicates that the level of preparation in a repetitive task is greater when a final response is required. No group differences were found for the other potentials.