1. EEG Correlates of Mindfulness and Expanded Self Experience
through Guided Subtraction Meditation
Scheiner, Grayson1; Soghoyan, Greg1; Gougelet, Robert1; Vahid,Ana2; Pineda, Jaime A.1
1Department of Cognitive Science, University of California San Diego; 2 Department of Psychology, University of California San Diego
Introduction
The World in One’s Mind
EEG Correlates of Mindful Perception
Neural Correlate of Ego Dissolution
EEG Changes
Using non-normalized, but cleaned and pruned EEG datasets from the resting baseline condition, we found a significant interaction between time and the meditation practice in global Alpha power increases. (p < 0.05 using parametric statistics and FDRs correction)
The world, as we see it, is a picture that lies flat on our retina. The mind perceptually fills in the world with complex generative mental models. Within this mental model, there exist conceptions of one’s self, one’s life, one’s human relationships, one’s body and the features of the world.
We administered an altered states of consciousness(5D-ASC) metric to practitioners at their 3rd and final time point.
We grouped those who scored over 2 standard deviations from the mean on the Dread of Ego Dissolution Subscale into a ‘Ego Dissolution’ group.
Using this grouping, we ran a 2x3 RM ANOVA and found an interaction between ego dissolution and relative hypo activation of the right Temporoparietal Junction(rTPJ) over time (F = 7.531, p=0.023).   
Background
We investigated the effects of the Guided Subtraction Meditation(GSM) practice, a new and unique meditation practice originating from South Korea.
This practice focuses on dissociating from the egoic mind through a method they call subtraction.
In this method, practitioners recall images and thoughts pertaining to past, present, and future experiences and mindfully observe them to realize that they are simply mental representations and not true reality.
The focus is then on discarding or ‘letting go,’ of these thoughts and images the purpose of waking up to the true reality and true self that exist behind these mental schema.
Minfulness: Mindfulness is about increasing active present awareness and seeing and accepting the world as it is. This is achieved through the Subtraction methodology by dissociating from and discarding the mentally generated model of the world and ego living in that world.
RESULTS
Behavioral
Significant increases in mindful awareness and mindful acceptance over the course of treatment for the Subtraction Meditation group.
The Subtraction method involves actively bringing up, dissociating from, and discarding thoughts and images of the human mind. This practice of mental cleansing increased the participants self reported awareness and acceptance on the Philadelphia Mindfulness Inventory.
Design
Summary and Conclusions
Guided Subtraction Meditation appears to be an effective method of meditation for increasing mindful acceptance and awareness.
These behavioral changes are accompanied by changes in the EEG which are most significant in the Alpha(8-13Hz) frequency bandwidth
These EEG changes are global, but specific features of the EEG correlate to specific behavioral changes.
We believe that the hypoactivation of the rTPJ for the ‘ego dissolution’ group is representative of inhibitory activity of parts of the DMN that account for perceptions of the embodied self.
We hope to continue research on this practice with more subjects and more advanced imaging techniques so that we can more deeply understand and verify the validity of neural correlates related to changes in self experience.
EEG Correlates of Mindfulness
There were significant correlations between Mindful Awareness and Occipital Alpha power increases(r = .558, p = 0.02) and Occipital Alpha increases and level of meditation practice(r=0.604, p = 0.005).
Subjects
Time 0-1 N = 22; 9 Meditators(6 Female), 13 Controls(6 Female)
Time 1-2 N = 12; 5 Meditators(4 Females), 7 Controls(5 Female)
EEG Data Collection and Analysis Methods
We recorded with a 32 channel BioSemi Active 2 EEG system.
Three conditions were recorded, an eyes closed resting baseline, a meditation task, and a ‘stillness’ task where practitioners were asked to keep their mind free of thoughts for 2 minutes.
Data was band pass filtered between 0.5 and 58 Hz, referenced to average, and inspected manually for artefactual epochs and channels.
After this, we concatenated all three condition files for each participant at each time point and performed SOBI ICA decomposition on this large file. Noisy components were then removed from the datasets through manual inspection.
We then interpolated missing electrodes and computed spectra for each 3 conditions separately using the well cleaned ICA data.
Spectral data was normalized across subjects so that it could be more stably used for between subject comparison. To do this, we subtracted each individuals eyes closed baseline spectrum from their other conditions’ power spectra.
EEG features were extracted from these normalized spectral power matrices using Matlab and analyzed then analyzed using SPSS.
Scalp topographies were obtained for visualization using EEGLAB’s STUDY function.
Meditation Group Power Spectrum
Time 1
Time 2
REFERENCES
Cahn, B. R., and Polich, J. (2006). Meditation states and traits: EEG, ERP, and neuroimaging studies. Psychol. Bull. 132, 180–211.
Snyder, A. C., and Foxe, J. J. (2010). Anticipatory attentional suppression of visual features indexed by oscillatory alpha-band power increases: a high-density electrical mapping study. J. Neurosci. 30, 4024–4032.
Oberman, L. M., Hubbard, E. M., McCleery, J. P., Altschuler, E. L., Ramachandran, V. S., & Pineda, J. a. (2005). Brain research. Cognitive brain research, 24(2), 190–8.
Iacoboni, M. (1999). Cortical Mechanisms of Human Imitation. Science, 286(5449), 2526–2528.
The above figure shows the average meditation group spectral power between time points 1 and 2 (n = 9). Using the normalized EEG data features, a 2X2 RM ANOVA indicated that there was an interaction between Alpha power increases, treatment and time
(F = 4.63, *p = corrected).
For reprints and communications,
Time 1
Time 2
Time 3