EEG Alpha-Rhythm-Related Changes in BOLD fMRI Signal in Neurofeedback Training.

Interaction of EEG and BOLD brain activity was studied in subjects during EEG-biofeedback training course (20 sessions). Healthy male subjects aged 20-35 underwent a training course of sound-reinforced upregulation of alpha- (20 participants) or beta-activity (9 participants). Pretraining, intermediate (after 10 sessions), and post-training fMRI-EEG recordings were conducted in resting state and during the participants' attempts to upregulate the power of target EEG activity. Regression analysis was carried out on three sessions in total; the main changes in BOLD signal connected with alpha rhythm power were related to the subjects who performed alpha training "good enough" (were able to increase alpha power at least at one stage). Maximum changes in BOLD response connected with alpha rhythm power were observed in the form of deactivation at T8 lead in the right hemisphere, and at F7 in the left hemisphere, and involved middle frontal gyrus, triangular part of inferior frontal gyrus, superior temporal gyrus, parietal lobule, and insula. The identified areas correspond to the executive control network (ECN) and anterior salience network (ASN).

Prospects of Synchronous fMRI-EEG Recording as the Basis for Neurofeedback (Exemplified on Patient with Stroke Sequelae).

Synchronous fMRI-EEG mapping of cerebral activity in stroke patients made it possible to implement neurofeedback, a novel and promising therapeutic technology. This method integrates a real-time monitoring of cerebral activity by EEG and fMRI signals and training of the patients to control this activity simultaneously or alternatively via neurofeedback. The targets of such cerebral stimulation are cortical regions controlling arbitrary movements (Brodmann area 4), whereas its aim is optimization of activity in these regions in order to achieve better rehabilitation of stroke patients. The paper discusses the methodical details, advantages, and promise of bimodal neurofeedback treatment.

Dynamics of fMRI and EEG Parameters in a Stroke Patient Assessed during a Neurofeedback Course Focused on Brodmann Area 4 (M1).

A course of interactive stimulation of primary motor cortex (Brodmann area 4) in the brain of a stroke patient resulted in recovery of locomotion volume in the paretic extremities and in improvement of general health accompanied with diverse changes in cerebral activity. During the training course, the magnitude of response in the visual fields of Brodmann areas 17 and 18 decreased; in parallel, the motor areas were supplemented with other ones such as area 24 (the ventral surface of anterior cingulate gyrus responsible for self-regulation of human brain activity and implicated into synthesis of tactile and special information) in company with Brodmann areas 40, 41, 43, 44, and 45. EEG data showed that neurofeedback sessions persistently increased the θ rhythm power in Brodmann areas 7, 39, 40, and 47, while the corresponding powers progressively decreased during a real motion. Both real motion and its virtual sibling constructed by interactive stimulation via neurofeedback were characterized with decreasing powers of the EEG ß rhythm in Brodmann areas 6 and 8. The neurofeedback course decreased the coherence between the left Brodmann area 6 and some other ones examined in α and θ ranges. In the context of real motions, the coherence assessed in the EEG ß range generally increased. Overall, the EEG and fMRI parameters attest to growing similarity between the moieties of functional communications effected in real and imaginary movements during neurofeedback course. The data open the vista for interactive stimulation to rehabilitate stroke patients; they highlight the important role of Brodmann areas in rearrangement of the brain in such patients; finally, the present results revealed the "common nervous pathway" that can be used to restore the capability for imaginary and real movements by a neurofeedback course after stroke.

Dynamics of Interaction of Neural Networks in the Course of EEG Alpha Biofeedback.

Brain EEG-fMRI activity was studied in subjects, who had successfully completed the EEG alpha stimulating training course (20 sessions): for 14 healthy men (20-35 years) three records were obtained in the feedback loop (biofeedback with EEG alpha rhythm with sound reinforcement): in the beginning, middle and at the end of the course. During alpha training, increased functional connectivity was revealed between precuneus network and anterior salience network, left executive control network, default mode network, primary visual network; anterior salience network and executive control network, visual-spatial network. The most prominent changes were found for precuneus network and anterior salience network, which could be due to their key role in the biofeedback phenomenon. Significant changes in functional connectivity were recorded for anterior salience network and precuneus network (synchronicity increased from the first to the third trial) and right and left executive control networks (weakening from the first to the second session.

[Experience of the Continuous Real Time fMRI Biofeedback of the Primary Motor Cortex Using a 1.5 T MR Scanner].

The neurofeedback based on the motor areas fMRI signal may be a promising treatment for improving motor impairment in post-stroke conditions and Parkinson's disease. In the majority of the studies has been conducted using the 3 T MR machines, and the region of interest has been placed to the secondary motor areas. The current study attempted to perform an fMRI neurofeeback based on response of the right hand projection locus within primary motor cortex utilizing the 1.5 T MR scanner and using the optimal parameters for the named magnetic field strength. The subjects were 16 healthy participants who underwent a 30-minute imaging session comprised 1) individual func- tional localization of the region of interest (using the hand clinging task) and attempts to control its activity with 2) motor imagery and 3) any cognitive strategy chosen by participant. In both self-regulation conditions subjects activated G. precentralis, G. cinguli anterior, G. frontalis superior, G. parietalis inferior, and 6-th Brodman area. Activation maps for these two tasks didn't differ one from another significantly, and the involved area had only a few overlays with the region of interest map which signifies that training was unsucessful. The limitations of the study and factors influenc- ing the biofeedback efficacy negatively are discussed.

EEG-fMRI Study of Alpha-Stimulation Neurobiofeedback Training Course.

fMRI-EEG dynamics of brain activity in volunteers was studied during the course of EEG alpha-stimulation training (20 sessions). Twenty-three healthy men (20-35 years) were subjected to 3-fold mapping in a feedback loop (EEG alpha-rhythm biofeedback with acoustic reinforcement). This procedure was performed at the beginning, middle, and end of the course. During the first neurofeedback training session, deactivation (p<0.001) was found in the right angular gyrus, supramarginal, and superior temporal gyri, Brodmann area 39, and cerebellum. Activation (p<0.001) was observed in the medial frontal and cingulate gyri, motor areas of both hemispheres, and Brodmann area 32. During final (third) neurofeedback training session, we observed strong deactivation (p<0.05 with FDR) of zones responsible for spatial thinking and motor functions: left medial frontal and left medial temporal gyri; right postcentral, lingual, and superior frontal gyri; insula and right side of the cerebellum; and precuneus and cuneus (Brodmann areas 6, 9, 7, 31, 8, 13, and 22). Changes in the alpha wave power were most pronounced in the primary and secondary somatosensory cortex of the left hemisphere (Brodmann areas 2L and 5L).