Fig 1.
Eye movement-related Independent Components' scalp maps.
The scalp maps of two sample Independent Components (ICs) extracted from EEG data, isolating activity generated by vertical (left) and horizontal (right) eye movements.
Fig 2.
Example of ocular activity extracted through ICA algorithm.
A. Vertical eye movements (some of which are marked by red arrows) are recorded on EOG channel, influence activity of Fp1, Fp2 fronto-polar electrodes (top panel) and are isolated into an Independent Component (bottom panel). B. Horizontal eye movements (one of which is marked by blue arrows) are recorded on EOG channel, influence activity of F7, F8 fronto-lateral electrodes (top panel) and are isolated into an Independent Component (bottom panel). In all plots: time is depicted on the abscissa in seconds and voltage on the ordinate in microVolts.
Fig 3.
Power spectra of ocular activity.
Power spectra of vertical (top plot) and horizontal (bottom plot) Independent Components of ocular activity, for a sample participant. The areas around 50 and 100 Hz have been removed from the plots and have been omitted from the analysis due to line noise harmonics.
Table 1.
The log-transformed power in band during the two tasks (FAM = Focused Attention Meditation on the breath; IMW = Instructed Mind-Wandering) for the Vertical Eye Movement (VEM) and Horizontal Eye Movement (HEM) Independent Components, and for EOG (electrooculogram) data. Values are expressed as mean ± standard deviation.
Fig 4.
Power in band of eye movements ICs during the two tasks.
Power in band relative to the two tasks (FAM = Focused Attention Meditation on the breath; IMW = Instructed Mind-Wandering) for the ICs that record activity of eye movements in the vertical (left panel) and horizontal axis (right panel). Circles represent average power across subjects, with vertical error bars for standard error of the mean. * indicates a significant difference between means for the corresponding band.
Fig 5.
Participants' Vertical Eye Movement ICs delta power as a function of their expertise in meditation.
Power in delta band (1–4 Hz) of individuals' Vertical Eye Movement Independent Component during the two tasks (FAM = Focused Attention Meditation on the breath; IMW = Instructed Mind-Wandering) as a function of individuals’ meditation expertise. Expertise in meditation Index was calculated for each subject as the product between amount of weekly meditation practice (in minutes) and time spent since attendance of the Mindfulness-Oriented Meditation course (in years).