The Sensorium: Psychophysiological Evaluation of Responses to a Multimodal Neurofeedback Environment

Mindfulness-based Neurofeedback: A Systematic Review of EEG and fMRI studies

Neurofeedback concurrent with mindfulness meditation may reveal meditation effects on the brain and facilitate improved mental health outcomes. Here, we systematically reviewed EEG and fMRI studies of mindfulness meditation with neurofeedback (mbNF) and followed PRISMA guidelines. We identified 10 fMRI reports, consisting of 177 unique participants, and 9 EEG reports, consisting of 242 participants. Studies of fMRI focused primarily on downregulating the default-mode network (DMN). Although studies found decreases in DMN activations during neurofeedback, there is a lack of evidence for transfer effects, and the majority of studies did not employ adequate controls, e.g. sham neurofeedback. Accordingly, DMN decreases may have been confounded by general task-related deactivation. EEG studies typically examined alpha, gamma, and theta frequency bands, with the most robust evidence supporting the modulation of theta band activity. Both EEG and fMRI mbNF have been implemented with high fidelity in clinical populations. However, the mental health benefits of mbNF have not been established. In general, mbNF studies would benefit from sham-controlled RCTs, as well as clear reporting (e.g. CRED-NF).

Cortical and autonomic responses during staged Taoist meditation: Two distinct meditation strategies

Meditation is a consciousness state associated with specific physiological and neural correlates. Numerous investigations of these correlates reported controversial results which prevented a consistent depiction of the underlying neurophysiological processes. Here we investigated the dynamics of multiple neurophysiological indicators during a staged meditation session. We measured the physiological changes at rest and during the guided Taoist meditation in experienced meditators and naive subjects. We recorded EEG, respiration, galvanic skin response, and photoplethysmography. All subjects followed the same instructions split into 16 stages. In the experienced meditators group we identified two subgroups with different physiological markers dynamics. One subgroup showed several signs of general relaxation evident from the changes in heart rate variability, respiratory rate, and EEG rhythmic activity. The other subgroup exhibited mind concentration patterns primarily noticeable in the EEG recordings while no autonomic responses occurred. The duration and type of previous meditation experience or any baseline indicators we measured did not explain the segregation of the meditators into these two groups. These results suggest that two distinct meditation strategies could be used by experienced meditators, which partly explains the inconsistent results reported in the earlier studies evaluating meditation effects. Our findings are also relevant to the development of the high-end biofeedback systems.

Skin Conductance Feedback Meditation: Evaluation of a Novel Physiology-Assisted Meditation Style

<b><i>Background:</i></b> Mindfulness meditation (MM) can be regarded as a practice for calming the mind, while the focus on their breathing can help meditators maintain a state of mindful presence. We have developed and evaluated an alternative method for reaching conscious states of pure being without the aid of a focus of attention. <b><i>Methods:</i></b> Skin conductance feedback was provided in real-time during meditation sessions (SCFM) and the practicability of this novel approach was evaluated. 30 participants - 15 meditation experts and 15 non-meditators - attended 6 sessions of meditation over the course of 3 days; 4 SCFM and 2 ordinary MM sessions were conducted. Each session was evaluated with physiological measures and a feedback questionnaire assessing subjective changes in body-related, emotional, and mental self-perception. <b><i>Results:</i></b> On average, 78.3% of the participants felt more integrated and connected, 84.2% perceived themselves as more calm and balanced, and 50% felt vitalized after SCFM sessions, while only 5% or less felt more agitated or depressed after the sessions. SCFM was not significantly different from MM. The positive effect of SCFM correlated positively with mindfulness self-ratings. <b><i>Conclusion:</i></b> The study demonstrates that SCFM is a viable method for performing a satisfying and consciousness-expanding meditation session.