Thermographic evaluation of mindfulness meditation using dynamic IR imaging

Meditation is a mental health training which helps to overwhelm the negative mental states. So far, many studies have shown the successful role of electrophysiological and neuroimaging techniques in the evaluation of meditation's effects on the functional and structural attributes of the brain. But the recording procedures of these techniques might be uncomfortable for the meditators. Unlike, the infrared thermography (IRT) is a highly noninvasive and human-friendly technique which requires minimal settings for data acquisition without violating the meditation procedure. The paper presents an IRT based approach to analyse the effect of mindfulness meditation on the autonomic activity characterized by thermal profile of forehead region. Moreover, the proposed approach enables the automatic extraction of forehead region which further automates the process of thermal data processing and analysis. In this study, the total of 18 subjects (9 meditators and 9 non-meditators) were involved in the imaging trail of dynamic facial thermography. To validate the study results, the obtained thermal data have been analysed (a) subjectively, based on the amplitude of normalized energy; and (b) objectively, by performing the one-way ANOVA test. Consequently, the objective analysis showed that the thermal profiles of both the groups are significantly different at probability, rho = 0.00074. In meditator group, the positive values of normalized energy have indicated that the mean temperature of forehead region increases during the meditation as a resultant of increased blood flow in the cerebral cortex of the brain and cutaneous vessels of the face. Meanwhile, in the case of non-meditators, the negative or small values of normalized energy have indicated that the forehead temperature either decreases or fluctuates around the baseline temperature. The findings of both the analysis indicate that the thermal profiles of meditator group are significantly different from those of non-meditators, except the subjects m6, n3 and n5. Hence, the facial IRT can be used as a bio-trainer and biofeedback system which assists both the meditators and novices to sustain and monitor the meditation performance quantitatively.