Endogenous spike discharges as conditioned stimuli in man

Neurofeedback in ADHD and insomnia: vigilance stabilization through sleep spindles and circadian networks

In this review article an overview of the history and current status of neurofeedback for the treatment of ADHD and insomnia is provided. Recent insights suggest a central role of circadian phase delay, resulting in sleep onset insomnia (SOI) in a sub-group of ADHD patients. Chronobiological treatments, such as melatonin and early morning bright light, affect the suprachiasmatic nucleus. This nucleus has been shown to project to the noradrenergic locus coeruleus (LC) thereby explaining the vigilance stabilizing effects of such treatments in ADHD. It is hypothesized that both Sensori-Motor Rhythm (SMR) and Slow-Cortical Potential (SCP) neurofeedback impact on the sleep spindle circuitry resulting in increased sleep spindle density, normalization of SOI and thereby affect the noradrenergic LC, resulting in vigilance stabilization. After SOI is normalized, improvements on ADHD symptoms will occur with a delayed onset of effect. Therefore, clinical trials investigating new treatments in ADHD should include assessments at follow-up as their primary endpoint rather than assessments at outtake. Furthermore, an implication requiring further study is that neurofeedback could be stopped when SOI is normalized, which might result in fewer sessions.

Control of chronic experimental focal epilepsy by feedback caudatum stimulations

The effects of feedback caudate nucleus (CN) stimulations (5 cycles/s, 0.3 ms, 1-5 V, 1-3 s) on the interictal spiking activity of epileptic foci automatically detected by a neuroanalyzer were followed in adult cats during 2-3 weeks of training. Spike depression occurred instantly after the onset of feedback stimulation, became stable after 3-4 days of operant training, and persisted with very little current reinforcement in a daily training schedule. No comparable effects were obtained either by random CN stimulation or by contingent stimulations of other subcortical structures such as the thalamus, the mesencephalic reticular formation, or the hypothalamus. A recovery of recurrent inhibitory caudate-cortical loops is presumed to contribute to the progressive normalization of cortical excitability obtained by training.

Reduction of seizures and normalization of the EEG in a severe epileptic following sensorimotor biofeedback training: preliminary study

Sensorimotor rhythm (SMR) biofeedback training was attempted in a 13-year-old male with frequent epileptic seizures. Prior to training the subject was averaging almost eight clinical seizures an hour. The SMR filter was tuned sharply to 12 plus or minus 1 Hz. Feedback was conducted over approximately six months and continues to the present. In that time the subject's percentage of SMR increased from about 10%, prior to training, to 65% after the 34th training session. Correspondingly, his rate of clinical seizures decreased by a factor of 10 and a significant reduction in percentage of epileptiform discharges was noted. Beginning with trial 35, the subject was provided feedback of epileptiform activity in combination with 12 Hz activity. The combined effect of these two treatment variables was to reduce the trial-to-trial variance in the dependent variables of interest.