Long-range parietal-occipital gamma-band desynchronisation underlies meditation-induced stabilisation of perception
Bistable perceptual tasks such as binocular rivalry demonstrate that human perception continuously fluctuates, with limited ability to control it. Previous behavioural studies have shown that long-term mental training through meditation practice enables a reduction of such fluctuations, thus stabilising perception. Using EEG, we investigated the neural bases of perceptual stabilisation in long-term meditators and age-matched meditation-naïve control participants. We measured binocular rivalry alternations before and after participants practiced meditation. We expected that perceptual stabilisation through meditation could occur via one of two neurocognitive mechanisms, greater attentional control or a disengaged/non-evaluative style of perception, corresponding to an increase or decrease in long-range phase synchronisation between sensory and higher-level visual regions respectively. Our results showed that long-term meditators perceived significantly longer mixed rivalry following concentrative meditation practice, indicating a stabilised non-evaluative perceptual state. The increase in mixed rivalry across individuals was strongly correlated with reduced parieto-occipital gamma-band (30–50 Hz) phase-synchrony. Our results show that perception can be stabilised through a non-evaluative stance that involves disabling communication within the visual hierarchy.