Mindfulness Meditators Show Enhanced Working Memory Performance Concurrent with Different Brain Region Engagement Patterns During Recall

Mindfulness meditation has been shown to improve working memory (WM). However, the altered brain activity underpinning these improvements is underexplored. In non-meditating individuals, modulation of theta and alpha oscillations and 1/f aperiodic activity during WM has been found to be related to WM performance. Resting theta and alpha oscillations have been found to differ in meditators, but WM related oscillation changes and 1/f aperiodic activity have not yet been examined. Additionally, WM event-related-potentials (ERPs) are modulated by attention, which is also enhanced by meditation, so these neural measures are candidates for exploring neural activity underpinning WM improvement in meditators. We recorded EEG from 29 controls and 29 meditators during a modified Sternberg WM task and compared theta, alpha, and 1/f aperiodic activity during the WM delay, and ERPs time-locked to the WM probe. Meditators responded more accurately (p = 0.008, Cohen’s d = 0.688). Meditators also showed different ERP distributions with earlier left-temporal activation and more frontal distribution of activity (FDR-p = 0.0186, η2 = 0.0903), as well as a reduction in overall neural response strength (FDR-p = 0.0098, η2 = 0.1251). While a higher proportion of meditators showed theta oscillations during the WM delay, no other differences in theta, alpha or 1/f aperiodic activity were present. These results suggest that increased WM performance in meditators might not be the result of higher amplitudes of typical WM activity, but instead due to an alternative neural strategy during WM decision making, which may allow more accurate responses with less neural activation. Highlights * Abbreviations : WM : Working Memory EEG : Electroencephalography MBSR : Mindfulness Based Stress Reduction MBCT : Mindfulness Based Cognitive Therapy FMI : Freiburg Mindfulness Inventory FFMQ : Five Facet Mindfulness Questionnaire ACC : Anterior Cingulate Cortex DLPFC : Dorsolateral Prefrontal Cortex ADHD : Attention-Deficit Hyperactivity Disorder BAI : Beck Anxiety Inventory BDI-II : Beck Depression Inventory II ICA : Independent Component Analysis AMICA : Adaptive Mixture Independent Component Analysis RAGU : Randomisation Graphical User Interface TCT : Topographical Consistency Test TANOVA : Topographical Analysis of Variance GFP : Global Field Potential RMS : Root Mean Squared FFT : Fast Fourier Transform FN400 : Frontal Negativity occurring ∼400 ms after probe stimuli in a working memory task Parietal old/new effect : Positive activity in parietal regions occurring ∼600 ms after probe stimuli in a working memory task P3 : Midline parietal positivity occurring 300 to 600 ms after stimuli in many different tasks