  Neurofeedback is a promising approach for non-invasive modulation of human
brain activity with applications for treatment of mental disorders and
enhancement of brain performance. Neurofeedback techniques are commonly based
on either electroencephalography (EEG) or real-time functional magnetic
resonance imaging (rtfMRI). Advances in simultaneous EEG-fMRI have made it
possible to combine the two approaches. Here we report the first implementation
of simultaneous multimodal rtfMRI and EEG neurofeedback (rtfMRI-EEG-nf). It is
based on a novel system for real-time integration of simultaneous rtfMRI and
EEG data streams. We applied the rtfMRI-EEG-nf to training of emotional
self-regulation in healthy subjects performing a positive emotion induction
task based on retrieval of happy autobiographical memories. The participants
were able to simultaneously regulate their BOLD fMRI activation in the left
amygdala and frontal EEG power asymmetry in the high-beta band using the
rtfMRI-EEG-nf. Our proof-of-concept results demonstrate the feasibility of
simultaneous self-regulation of both hemodynamic (rtfMRI) and
electrophysiological (EEG) activity of the human brain. They suggest potential
applications of rtfMRI-EEG-nf in the development of novel cognitive
neuroscience research paradigms and enhanced cognitive therapeutic approaches
for major neuropsychiatric disorders, particularly depression.
