bioRxiv (Cold Spring Harbor Laboratory), Feb 6, 2023
Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and... more Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and mental health. The objective was to study the information exchange between symmetric electrodes across the hemispheres during meditation using functional connectivity (FC) measures. We investigate the changes in the coherence between EEG electrode pairs during the meditation practiced by long-term Brahmakumaris Rajyoga meditators with open eyes and during listening to music by controls as the comparable task. Two distinct FC measures derived from coherency, namely, magnitude squared coherence (MSC) and imaginary part of coherency (ICoh) are used to study the changes in interhemispheric coherence. During baseline conditions, higher MSC is found in meditators in frontocentral and centroparietal regions and higher |ICoh| globally in higher beta and gamma bands than controls. Further, in meditators, the MSC significantly increases in higher theta and alpha bands in the frontal and parietal regions and |ICoh| significantly decreases across all regions and bands except in the alpha band during meditation. However, the control subjects with no knowledge of meditation show no change in theta or alpha MSC or |ICoh| during the music session. Distinct patterns of changes are observed with the two FC measures in different frequency bands during meditation in the meditators and music-listening session in the control subjects indicating varied information processing between the right and left hemispheres and differences in the FC measures used. We found increased MSC and decreased |ICoh| between the frontal electrodes implying increased self-awareness in meditators. The MSC between the occipital electrodes in meditators is less than the controls in baseline condition indicating a possible modified visual information processing in Rajyoga meditators due to the long-term practice of meditation with open eyes. Overall, the changes in MSC indicate increased functional integration during meditation supporting the hypothesis of cortical integration theory. .
It is of utmost importance to protect our health-care professionals, who are the most important r... more It is of utmost importance to protect our health-care professionals, who are the most important resources for any country today. The commitment behind this article and proposal is to ensure that we do not lose even one more doctor or nurse to COVID-19. In the opinion of the authors, the current design of most of the ICUs, where the air is recirculated through the airconditioning , is not suited for treating the highly infectious patients of COVID-19, and may be one of the causes of the thousands of infections among the healthcare workers, which has also led to the death of over 500 of them around the world. One is not sure whether this is the reason behind the unusual death rate of patients put on ventilators too. This article proposes a cost-effective redesign of the existing ICUs and suggestions for choosing the buildings intended to be converted to makeshift hospitals to take care of the patients infected by the corona virus. Also, where the personal protective equipment is in shortage, certain possible alternatives are suggested.
Effects of meditation on electroencephalographic (EEG) activity are still being investigated desp... more Effects of meditation on electroencephalographic (EEG) activity are still being investigated despite decades of research. Neurophysiological correlation during meditation has been empirically postulated using different time and frequency domain entropy features of EEG. EEG has been recorded from fifteen Rajayoga meditators practiced by Prajapita Brahmakumaris World Spiritual University. Most of the meditators have shown increase in time domain fuzzy based entropy in frontal region during meditation. We have compared the data recorded during the peace and angelic meditation practices. The mean of the entropy values in each state is used to study the meditation and non-meditation states. Analysis has been carried out region wise. The frontal region shows significant increase in the entropy values during the meditative states.
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Nov 1, 2021
Meditation practices are considered mental training and have increasingly received attention from... more Meditation practices are considered mental training and have increasingly received attention from the scientific community due to their potential psychological and physical health benefits. We compared the EEG data recorded from long-term rajayoga practitioners during different meditative and non-meditative periods. Minimum variance modified fuzzy entropy (MVMFE) is computed for each EEG band for all channels of a given lobe. The means across all the channel entropy values were obtained and compared during meditative and non-meditative states. Meditators showed higher frontal entropy in the lower gamma band (25-45Hz) during the meditative states. Independent component analysis was applied to ensure that muscle or eye artifacts did not contribute to the gamma activity. Our results extend previous findings on the changes in entropy observed in long-term meditators during rajayoga practice. Gamma band in EEG is implicated in cognitive processes requiring high-level processing such as attention, learning, memory control, and retrieval. Gamma activity is also suggested as a potential biomarker for therapeutic progress in patients with clinical depression. Based on our findings, there is an excellent possibility to utilize the practice of meditation as a training tool to strengthen the neural circuits, where age-related degeneration is making its pathological impact.
DOAJ (DOAJ: Directory of Open Access Journals), Jan 19, 2018
Rajyoga meditation is taught by Prajapita Brahmakumaris World Spiritual University (Brahmakumaris... more Rajyoga meditation is taught by Prajapita Brahmakumaris World Spiritual University (Brahmakumaris) and has been followed by more than one million followers across the globe. However, rare studies were conducted on physiological aspects of rajyoga meditation using electroencephalography (EEG). Band power and cortical asymmetry were not studied with Rajyoga meditators. This study aims to investigate the effect of regular meditation practice on EEG brain dynamics in low-frequency bands of long-term Rajyoga meditators. Subjects were matched for age in both groups. Lower frequency EEG bands were analyzed in resting and during meditation. Twenty-one male long-term meditators (LTMs) and same number of controls were selected to participate in study as par inclusion criteria. Semi high-density EEG was recorded before and during meditation in LTM group and resting in control group. The main outcome of the study was spectral power of alpha and theta bands and cortical (hemispherical) asymmetry calculated using band power. One-way ANOVA was performed to find the significant difference between EEG spectral properties of groups. Pearson's Chi-square test was used to find difference among demographics data. Results reveal high-band power in alpha and theta spectra in meditators. Cortical asymmetry calculated through EEG power was also found to be high in frontal as well as parietal channels. However, no correlation was seen between the experience of meditation (years, hours) practice and EEG indices. Overall findings indicate contribution of smaller frequencies (alpha and theta) while maintaining meditative experience. This suggests a positive impact of meditation on frontal and parietal areas of brain, involved in the processes of regulation of selective and sustained attention as well as provide evidence about their involvement in emotion and cognitive processing.
Meditation has a versatile nature to affect the cognitive functioning of human brain. Recent rese... more Meditation has a versatile nature to affect the cognitive functioning of human brain. Recent researches demonstrated its effects on white matter properties of the human brain. In this research, we aim to investigate white matter microstructure of corpus callosum (CC) in long-term meditators (LTM) of rajayoga meditation using diffusion tensor imaging (DTI). For this cross-sectional analysis, twenty-two LTM and seventeen control participants of age ranged (30-50 yrs.) were recruited. Results show high fractional anisotropy (FA) values with low mean diffusivity (MD) in whole as well as different segments of CC in LTM group. Also, the experience of meditation was correlated with white matter properties of CC tracts. Findings may suggest rajayoga meditation to bring potential changes in the microstructure of CC segments. Further studies are suggested in clinical population to check its validity and efficacy against disorders involved agenesis of white matter.
Objective: The objective is to analyze EEG recorded during Brahmakumaris Rajyoga meditation (BKRY... more Objective: The objective is to analyze EEG recorded during Brahmakumaris Rajyoga meditation (BKRYM) using eLORETA applied in the frequency domain for localizing sources during meditation vis-Ă -vis baseline condition. Unlike many other popular meditation practices, BKRYM is practiced with open eyes. To our knowledge, there has been no study of the changes in the brain's activity during the practice of BKRYM using source localization. Further, this seed-stage meditation goes through specific stages, and the corresponding changes in brain activity, including the different brain networks are explored. Method: EEG recorded during Brahmakumaris seed-stage meditation was studied in 52 long-term meditators. The meditation comprised three stages, namely focusing on peace, imagining being a soul, and communion with the Supreme soul. Brain electric source localization in the frequency domain was used on multichannel EEG recordings to establish activation differences between meditation and open-eyed, task-free resting. Additional exploratory analyses were performed for the differences between initial rest, meditation, and final rest. Results: After 5000 randomized statistical tests of significance (p<0.05), meditation showed reduced activity in the delta and increased activity in low alpha frequencies. The brain networks altered in their activation during meditation are the following: central executive network, mirroring network, task-positive, and task-negative networks. Conclusions: The observed changes in activity reflect the main cognitive-affective and behavioral specifics of seed-stage meditation: attention modulation, self-related processing, visual imagery, and extracorporeal experience. Future studies need to distinctly differentiate between the stages of meditation.
2020 IEEE Bangalore Humanitarian Technology Conference (B-HTC), Oct 8, 2020
It is of utmost importance to protect our healthcare professionals, who are the most important re... more It is of utmost importance to protect our healthcare professionals, who are the most important resources for any country today. The commitment behind this article and proposal is to ensure that we do not lose even one more doctor or nurse to COVID-19. In the opinion of the authors, the current design of most of the ICUs, where the air is recirculated through the airconditioning , is not suited for treating the highly infectious patients of COVID-19, and may be one of the causes of the thousands of infections among the healthcare workers, which has also led to the death of more than two thousands of them around the world. One is not sure whether this is the reason behind the unusual death rate of patients put on ventilators too. This article proposes a cost-effective redesign of the existing ICUs and suggestions for choosing the buildings intended to be converted to makeshift hospitals to take care of the patients infected by the corona virus. Also, where the personal protective equipment is in shortage, certain possible alternatives are suggested. There is also the need to revise the curricula for medicine and nursing to make them sufficiently aware of the risks posed by ICUs and also about lifestyle changes for positive health and prevention, rather than purely for patient care.
This work proposes improvements in the electroencephalogram (EEG) recording protocols for motor i... more This work proposes improvements in the electroencephalogram (EEG) recording protocols for motor imagery through the introduction of actual motor movement and/or somatosensory cues. The results obtained demonstrate the advantage of requiring the subjects to perform motor actions following the trials of imagery. By introducing motor actions in the protocol, the subjects are able to perform actual motor planning, rather than just visualizing the motor movement, thus greatly improving the ease with which the motor movements can be imagined. This study also probes the added advantage of administering somatosensory cues in the subject, as opposed to the conventional auditory/visual cues. These changes in the protocol show promise in terms of the aptness of the spatial filters obtained on the data, on application of the well-known common spatial pattern (CSP) algorithms. The regions highlighted by the spatial filters are more localized and consistent across the subjects when the protocol is augmented with somatosensory stimuli. Hence, we suggest that this may prove to be a better EEG acquisition protocol for detecting brain activation in response to intended motor commands in (clinically) paralyzed/locked-in patients.
The performance of functional connectivity metrics is investigated for electroencephalogram (EEG)... more The performance of functional connectivity metrics is investigated for electroencephalogram (EEG)-based biometrics using a support vector machine classifier. Experiments are conducted on a heterogeneous EEG dataset of 184 subjects formed by pooling three distinct datasets recorded with different systems and protocols. The identification accuracy is found to be higher for higher frequency EEG bands, indicating the enhanced uniqueness of the neural signatures in beta and gamma bands. Using all the 56 EEG channels common to the three databases, the best identification accuracy of 97.4% is obtained using phase locking value-based measures extracted from the gamma frequency band. When the number of channels is reduced to 21 from 56, there is a marginal reduction of 2.4% only in the identification accuracy. Additional experiments are conducted to study the effect of the cognitive state of the subject and mismatched train/test conditions on the system performance.
We present an end-to-end system for dichoptic stimuli presentation and response capture. The lowe... more We present an end-to-end system for dichoptic stimuli presentation and response capture. The lower bound for the inter-stimulus interval of the proposed system is approximately 17 ms. The efficiency of the proposed system is demonstrated using a match-to-sample (MTS) paradigm for measuring the reaction time of 29 males aged between 18 and 22 years and 29 females aged between 19 and 22 years in matching three unique hues, namely red, blue, and green. Using VR glasses ensures that the perception of the colours determined by the three attributes of hue, brightness, and saturation is precisely controlled across trials and subjects, independent of the ambient lighting. It is observed that males have around 16% shorter reaction time than females (p <0.001). Understanding sex differences in the time taken to match colours helps in a more accurate interpretation of results in studies on sex differences in cognition that use colours. It also helps better understand the disease process of neurological disorders affecting visual perception that manifest differently in males and females. The Android code for the entire system is available as open-source code.
By recording ECG and breath signals from 10 normal male subjects during symmetric breathing at co... more By recording ECG and breath signals from 10 normal male subjects during symmetric breathing at controlled rates, including breath hold to achieve low breathing rates, heart rate variability (HRV) and variations in the peak to peak amplitude of the R to S wave are analyzed. The subjects synchronized their breathing rate to an auditory metronome, which was programmed to generate two equispaced tones for every cycle, at rates of 60 down to 2 cycles per minute. The amplitude of the RS-wave varies negatively correlated to the respiratory signal. The respiration-inspired fluctuations in the heart rate continue during the breath-held intervals too, and the variations undergo two or three cycles in every respiration cycle for very low breathing rates. On the other hand, R-S amplitude does not change significantly during breath hold before or after inspiration. Thus, for very slow breathing, the RS-wave amplitude spectrum has a peak at the respiration rate mainly, whereas the HRV spectrum has significant peaks at the second and third harmonics of the respiration rate also.
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Nov 1, 2021
Phonemes are classified into different categories based on the place and manner of articulation. ... more Phonemes are classified into different categories based on the place and manner of articulation. We investigate the differences between the neural correlates of imagined nasal and bilabial consonants (distinct phonological categories). Mean phase coherence is used as a metric for measuring the phase synchronisation between pairs of electrodes in six cortical regions (auditory, motor, prefrontal, sensorimotor, somatosensory and premotor) during the imagery of nasal and bilabial consonants. Statistically significant difference at 95% confidence interval is observed in beta and lower-gamma bands in various cortical regions. Our observations are inline with the directions into velocities of articulators and dual stream prediction models and support the hypothesis that phonological categories not only exist in articulated speech but can also be distinguished from the EEG of imagined speech. Clinical relevance-Identification of neural correlates of imagined speech helps in developing better prompts for imagined speech based brain-computer interfaces (BCI) leading to improvements in both accuracy and degrees of freedom. BCIs play a significant role as technology aids for differently abled individuals and for patients with disorders of consciousness (DoC). It also helps in better understanding the neural correlates of psychotic disorders such as schizophrenia and paranoia where auditory hallucinations is a major symptom.
Electroencephalogram (EEG) is investigated for changes in the pattern of brain activity during me... more Electroencephalogram (EEG) is investigated for changes in the pattern of brain activity during meditation. Correlation between the neural activity in each region with those of other regions of the brain are studied. EEG recorded from fifteen practitioners of the peace and angelic meditations, being part of the Rajayoga meditation of Prajapita Brahmakumaris World Spiritual University is analyzed for this study. The mean and variance of the Frobenius norms of the difference matrices between the covariance matrices of successive epochs is used to study the meditative and non-meditative states. Analysis has been carried out region wise. The covariance matrices become more uniform during meditation, leading to decreased distance between matrices of successive epochs. The frontal region shows significantly decreased distances between the covariance matrices during meditation.
Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and... more Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and mental health. The objective was to study the information exchange between symmetric electrodes across the hemispheres during meditation using functional connectivity (FC) measures. We investigate the changes in the coherence between EEG electrode pairs during the meditation practiced by long-term Brahmakumaris Rajyoga meditators with open eyes and during listening to music by controls as the comparable task. Two distinct FC measures derived from coherency, namely, magnitude squared coherence (MSC) and imaginary part of coherency (ICoh) are used to study the changes in interhemispheric coherence. During baseline conditions, higher MSC is found in meditators in frontocentral and centroparietal regions and higher |ICoh| globally in higher beta and gamma bands than controls. Further, in meditators, the MSC significantly increases in higher theta and alpha bands in the frontal and parietal ...
2020 IEEE 17th India Council International Conference (INDICON), 2020
Effects of meditation on electroencephalographic (EEG) activity are still being investigated desp... more Effects of meditation on electroencephalographic (EEG) activity are still being investigated despite decades of research. Neurophysiological correlation during meditation has been empirically postulated using different time and frequency domain entropy features of EEG. EEG has been recorded from fifteen Rajayoga meditators practiced by Prajapita Brahmakumaris World Spiritual University. Most of the meditators have shown increase in time domain fuzzy based entropy in frontal region during meditation. We have compared the data recorded during the peace and angelic meditation practices. The mean of the entropy values in each state is used to study the meditation and non-meditation states. Analysis has been carried out region wise. The frontal region shows significant increase in the entropy values during the meditative states.
TENCON 2021 - 2021 IEEE Region 10 Conference (TENCON), 2021
This study proposes an approach to classify the EEG into meditation and non-meditation segments u... more This study proposes an approach to classify the EEG into meditation and non-meditation segments using a long short-term memory (LSTM) based deep neural network (DNN) framework. Inter-subject classification performance is assessed on EEG recorded from fourteen long-term Rajayoga meditators. Common spatial pattern is used for feature extraction, and linear discriminant analysis is used for dimensionality reduction. The sequence of features thus obtained is fed to a LSTM based DNN, which employs a fully connected layer for classification. We have achieved inter-subject classification accuracies of 79.1 %, 86.5%, 91.0%, and 94.1% with the respective use of the alpha, beta, lower-gamma, and higher-gamma bands for classification. To the best of our knowledge, this is the first work to employ deep learning to distinguish between the brain's electrical activity during meditation and at rest.
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC)
Meditation practices are considered mental training and have increasingly received attention from... more Meditation practices are considered mental training and have increasingly received attention from the scientific community due to their potential psychological and physical health benefits. We compared the EEG data recorded from long-term rajayoga practitioners during different meditative and non-meditative periods. Minimum variance modified fuzzy entropy (MVMFE) is computed for each EEG band for all channels of a given lobe. The means across all the channel entropy values were obtained and compared during meditative and non-meditative states. Meditators showed higher frontal entropy in the lower gamma band (25-45Hz) during the meditative states. Independent component analysis was applied to ensure that muscle or eye artifacts did not contribute to the gamma activity. Our results extend previous findings on the changes in entropy observed in long-term meditators during rajayoga practice. Gamma band in EEG is implicated in cognitive processes requiring high-level processing such as attention, learning, memory control, and retrieval. Gamma activity is also suggested as a potential biomarker for therapeutic progress in patients with clinical depression. Based on our findings, there is an excellent possibility to utilize the practice of meditation as a training tool to strengthen the neural circuits, where age-related degeneration is making its pathological impact.
bioRxiv (Cold Spring Harbor Laboratory), Feb 6, 2023
Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and... more Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and mental health. The objective was to study the information exchange between symmetric electrodes across the hemispheres during meditation using functional connectivity (FC) measures. We investigate the changes in the coherence between EEG electrode pairs during the meditation practiced by long-term Brahmakumaris Rajyoga meditators with open eyes and during listening to music by controls as the comparable task. Two distinct FC measures derived from coherency, namely, magnitude squared coherence (MSC) and imaginary part of coherency (ICoh) are used to study the changes in interhemispheric coherence. During baseline conditions, higher MSC is found in meditators in frontocentral and centroparietal regions and higher |ICoh| globally in higher beta and gamma bands than controls. Further, in meditators, the MSC significantly increases in higher theta and alpha bands in the frontal and parietal regions and |ICoh| significantly decreases across all regions and bands except in the alpha band during meditation. However, the control subjects with no knowledge of meditation show no change in theta or alpha MSC or |ICoh| during the music session. Distinct patterns of changes are observed with the two FC measures in different frequency bands during meditation in the meditators and music-listening session in the control subjects indicating varied information processing between the right and left hemispheres and differences in the FC measures used. We found increased MSC and decreased |ICoh| between the frontal electrodes implying increased self-awareness in meditators. The MSC between the occipital electrodes in meditators is less than the controls in baseline condition indicating a possible modified visual information processing in Rajyoga meditators due to the long-term practice of meditation with open eyes. Overall, the changes in MSC indicate increased functional integration during meditation supporting the hypothesis of cortical integration theory. .
It is of utmost importance to protect our health-care professionals, who are the most important r... more It is of utmost importance to protect our health-care professionals, who are the most important resources for any country today. The commitment behind this article and proposal is to ensure that we do not lose even one more doctor or nurse to COVID-19. In the opinion of the authors, the current design of most of the ICUs, where the air is recirculated through the airconditioning , is not suited for treating the highly infectious patients of COVID-19, and may be one of the causes of the thousands of infections among the healthcare workers, which has also led to the death of over 500 of them around the world. One is not sure whether this is the reason behind the unusual death rate of patients put on ventilators too. This article proposes a cost-effective redesign of the existing ICUs and suggestions for choosing the buildings intended to be converted to makeshift hospitals to take care of the patients infected by the corona virus. Also, where the personal protective equipment is in shortage, certain possible alternatives are suggested.
Effects of meditation on electroencephalographic (EEG) activity are still being investigated desp... more Effects of meditation on electroencephalographic (EEG) activity are still being investigated despite decades of research. Neurophysiological correlation during meditation has been empirically postulated using different time and frequency domain entropy features of EEG. EEG has been recorded from fifteen Rajayoga meditators practiced by Prajapita Brahmakumaris World Spiritual University. Most of the meditators have shown increase in time domain fuzzy based entropy in frontal region during meditation. We have compared the data recorded during the peace and angelic meditation practices. The mean of the entropy values in each state is used to study the meditation and non-meditation states. Analysis has been carried out region wise. The frontal region shows significant increase in the entropy values during the meditative states.
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Nov 1, 2021
Meditation practices are considered mental training and have increasingly received attention from... more Meditation practices are considered mental training and have increasingly received attention from the scientific community due to their potential psychological and physical health benefits. We compared the EEG data recorded from long-term rajayoga practitioners during different meditative and non-meditative periods. Minimum variance modified fuzzy entropy (MVMFE) is computed for each EEG band for all channels of a given lobe. The means across all the channel entropy values were obtained and compared during meditative and non-meditative states. Meditators showed higher frontal entropy in the lower gamma band (25-45Hz) during the meditative states. Independent component analysis was applied to ensure that muscle or eye artifacts did not contribute to the gamma activity. Our results extend previous findings on the changes in entropy observed in long-term meditators during rajayoga practice. Gamma band in EEG is implicated in cognitive processes requiring high-level processing such as attention, learning, memory control, and retrieval. Gamma activity is also suggested as a potential biomarker for therapeutic progress in patients with clinical depression. Based on our findings, there is an excellent possibility to utilize the practice of meditation as a training tool to strengthen the neural circuits, where age-related degeneration is making its pathological impact.
DOAJ (DOAJ: Directory of Open Access Journals), Jan 19, 2018
Rajyoga meditation is taught by Prajapita Brahmakumaris World Spiritual University (Brahmakumaris... more Rajyoga meditation is taught by Prajapita Brahmakumaris World Spiritual University (Brahmakumaris) and has been followed by more than one million followers across the globe. However, rare studies were conducted on physiological aspects of rajyoga meditation using electroencephalography (EEG). Band power and cortical asymmetry were not studied with Rajyoga meditators. This study aims to investigate the effect of regular meditation practice on EEG brain dynamics in low-frequency bands of long-term Rajyoga meditators. Subjects were matched for age in both groups. Lower frequency EEG bands were analyzed in resting and during meditation. Twenty-one male long-term meditators (LTMs) and same number of controls were selected to participate in study as par inclusion criteria. Semi high-density EEG was recorded before and during meditation in LTM group and resting in control group. The main outcome of the study was spectral power of alpha and theta bands and cortical (hemispherical) asymmetry calculated using band power. One-way ANOVA was performed to find the significant difference between EEG spectral properties of groups. Pearson&amp;amp;amp;amp;amp;amp;#39;s Chi-square test was used to find difference among demographics data. Results reveal high-band power in alpha and theta spectra in meditators. Cortical asymmetry calculated through EEG power was also found to be high in frontal as well as parietal channels. However, no correlation was seen between the experience of meditation (years, hours) practice and EEG indices. Overall findings indicate contribution of smaller frequencies (alpha and theta) while maintaining meditative experience. This suggests a positive impact of meditation on frontal and parietal areas of brain, involved in the processes of regulation of selective and sustained attention as well as provide evidence about their involvement in emotion and cognitive processing.
Meditation has a versatile nature to affect the cognitive functioning of human brain. Recent rese... more Meditation has a versatile nature to affect the cognitive functioning of human brain. Recent researches demonstrated its effects on white matter properties of the human brain. In this research, we aim to investigate white matter microstructure of corpus callosum (CC) in long-term meditators (LTM) of rajayoga meditation using diffusion tensor imaging (DTI). For this cross-sectional analysis, twenty-two LTM and seventeen control participants of age ranged (30-50 yrs.) were recruited. Results show high fractional anisotropy (FA) values with low mean diffusivity (MD) in whole as well as different segments of CC in LTM group. Also, the experience of meditation was correlated with white matter properties of CC tracts. Findings may suggest rajayoga meditation to bring potential changes in the microstructure of CC segments. Further studies are suggested in clinical population to check its validity and efficacy against disorders involved agenesis of white matter.
Objective: The objective is to analyze EEG recorded during Brahmakumaris Rajyoga meditation (BKRY... more Objective: The objective is to analyze EEG recorded during Brahmakumaris Rajyoga meditation (BKRYM) using eLORETA applied in the frequency domain for localizing sources during meditation vis-Ă -vis baseline condition. Unlike many other popular meditation practices, BKRYM is practiced with open eyes. To our knowledge, there has been no study of the changes in the brain&#39;s activity during the practice of BKRYM using source localization. Further, this seed-stage meditation goes through specific stages, and the corresponding changes in brain activity, including the different brain networks are explored. Method: EEG recorded during Brahmakumaris seed-stage meditation was studied in 52 long-term meditators. The meditation comprised three stages, namely focusing on peace, imagining being a soul, and communion with the Supreme soul. Brain electric source localization in the frequency domain was used on multichannel EEG recordings to establish activation differences between meditation and open-eyed, task-free resting. Additional exploratory analyses were performed for the differences between initial rest, meditation, and final rest. Results: After 5000 randomized statistical tests of significance (p&lt;0.05), meditation showed reduced activity in the delta and increased activity in low alpha frequencies. The brain networks altered in their activation during meditation are the following: central executive network, mirroring network, task-positive, and task-negative networks. Conclusions: The observed changes in activity reflect the main cognitive-affective and behavioral specifics of seed-stage meditation: attention modulation, self-related processing, visual imagery, and extracorporeal experience. Future studies need to distinctly differentiate between the stages of meditation.
2020 IEEE Bangalore Humanitarian Technology Conference (B-HTC), Oct 8, 2020
It is of utmost importance to protect our healthcare professionals, who are the most important re... more It is of utmost importance to protect our healthcare professionals, who are the most important resources for any country today. The commitment behind this article and proposal is to ensure that we do not lose even one more doctor or nurse to COVID-19. In the opinion of the authors, the current design of most of the ICUs, where the air is recirculated through the airconditioning , is not suited for treating the highly infectious patients of COVID-19, and may be one of the causes of the thousands of infections among the healthcare workers, which has also led to the death of more than two thousands of them around the world. One is not sure whether this is the reason behind the unusual death rate of patients put on ventilators too. This article proposes a cost-effective redesign of the existing ICUs and suggestions for choosing the buildings intended to be converted to makeshift hospitals to take care of the patients infected by the corona virus. Also, where the personal protective equipment is in shortage, certain possible alternatives are suggested. There is also the need to revise the curricula for medicine and nursing to make them sufficiently aware of the risks posed by ICUs and also about lifestyle changes for positive health and prevention, rather than purely for patient care.
This work proposes improvements in the electroencephalogram (EEG) recording protocols for motor i... more This work proposes improvements in the electroencephalogram (EEG) recording protocols for motor imagery through the introduction of actual motor movement and/or somatosensory cues. The results obtained demonstrate the advantage of requiring the subjects to perform motor actions following the trials of imagery. By introducing motor actions in the protocol, the subjects are able to perform actual motor planning, rather than just visualizing the motor movement, thus greatly improving the ease with which the motor movements can be imagined. This study also probes the added advantage of administering somatosensory cues in the subject, as opposed to the conventional auditory/visual cues. These changes in the protocol show promise in terms of the aptness of the spatial filters obtained on the data, on application of the well-known common spatial pattern (CSP) algorithms. The regions highlighted by the spatial filters are more localized and consistent across the subjects when the protocol is augmented with somatosensory stimuli. Hence, we suggest that this may prove to be a better EEG acquisition protocol for detecting brain activation in response to intended motor commands in (clinically) paralyzed/locked-in patients.
The performance of functional connectivity metrics is investigated for electroencephalogram (EEG)... more The performance of functional connectivity metrics is investigated for electroencephalogram (EEG)-based biometrics using a support vector machine classifier. Experiments are conducted on a heterogeneous EEG dataset of 184 subjects formed by pooling three distinct datasets recorded with different systems and protocols. The identification accuracy is found to be higher for higher frequency EEG bands, indicating the enhanced uniqueness of the neural signatures in beta and gamma bands. Using all the 56 EEG channels common to the three databases, the best identification accuracy of 97.4% is obtained using phase locking value-based measures extracted from the gamma frequency band. When the number of channels is reduced to 21 from 56, there is a marginal reduction of 2.4% only in the identification accuracy. Additional experiments are conducted to study the effect of the cognitive state of the subject and mismatched train/test conditions on the system performance.
We present an end-to-end system for dichoptic stimuli presentation and response capture. The lowe... more We present an end-to-end system for dichoptic stimuli presentation and response capture. The lower bound for the inter-stimulus interval of the proposed system is approximately 17 ms. The efficiency of the proposed system is demonstrated using a match-to-sample (MTS) paradigm for measuring the reaction time of 29 males aged between 18 and 22 years and 29 females aged between 19 and 22 years in matching three unique hues, namely red, blue, and green. Using VR glasses ensures that the perception of the colours determined by the three attributes of hue, brightness, and saturation is precisely controlled across trials and subjects, independent of the ambient lighting. It is observed that males have around 16% shorter reaction time than females (p <0.001). Understanding sex differences in the time taken to match colours helps in a more accurate interpretation of results in studies on sex differences in cognition that use colours. It also helps better understand the disease process of neurological disorders affecting visual perception that manifest differently in males and females. The Android code for the entire system is available as open-source code.
By recording ECG and breath signals from 10 normal male subjects during symmetric breathing at co... more By recording ECG and breath signals from 10 normal male subjects during symmetric breathing at controlled rates, including breath hold to achieve low breathing rates, heart rate variability (HRV) and variations in the peak to peak amplitude of the R to S wave are analyzed. The subjects synchronized their breathing rate to an auditory metronome, which was programmed to generate two equispaced tones for every cycle, at rates of 60 down to 2 cycles per minute. The amplitude of the RS-wave varies negatively correlated to the respiratory signal. The respiration-inspired fluctuations in the heart rate continue during the breath-held intervals too, and the variations undergo two or three cycles in every respiration cycle for very low breathing rates. On the other hand, R-S amplitude does not change significantly during breath hold before or after inspiration. Thus, for very slow breathing, the RS-wave amplitude spectrum has a peak at the respiration rate mainly, whereas the HRV spectrum has significant peaks at the second and third harmonics of the respiration rate also.
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Nov 1, 2021
Phonemes are classified into different categories based on the place and manner of articulation. ... more Phonemes are classified into different categories based on the place and manner of articulation. We investigate the differences between the neural correlates of imagined nasal and bilabial consonants (distinct phonological categories). Mean phase coherence is used as a metric for measuring the phase synchronisation between pairs of electrodes in six cortical regions (auditory, motor, prefrontal, sensorimotor, somatosensory and premotor) during the imagery of nasal and bilabial consonants. Statistically significant difference at 95% confidence interval is observed in beta and lower-gamma bands in various cortical regions. Our observations are inline with the directions into velocities of articulators and dual stream prediction models and support the hypothesis that phonological categories not only exist in articulated speech but can also be distinguished from the EEG of imagined speech. Clinical relevance-Identification of neural correlates of imagined speech helps in developing better prompts for imagined speech based brain-computer interfaces (BCI) leading to improvements in both accuracy and degrees of freedom. BCIs play a significant role as technology aids for differently abled individuals and for patients with disorders of consciousness (DoC). It also helps in better understanding the neural correlates of psychotic disorders such as schizophrenia and paranoia where auditory hallucinations is a major symptom.
Electroencephalogram (EEG) is investigated for changes in the pattern of brain activity during me... more Electroencephalogram (EEG) is investigated for changes in the pattern of brain activity during meditation. Correlation between the neural activity in each region with those of other regions of the brain are studied. EEG recorded from fifteen practitioners of the peace and angelic meditations, being part of the Rajayoga meditation of Prajapita Brahmakumaris World Spiritual University is analyzed for this study. The mean and variance of the Frobenius norms of the difference matrices between the covariance matrices of successive epochs is used to study the meditative and non-meditative states. Analysis has been carried out region wise. The covariance matrices become more uniform during meditation, leading to decreased distance between matrices of successive epochs. The frontal region shows significantly decreased distances between the covariance matrices during meditation.
Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and... more Meditation is a self-regulatory process practiced primarily to reduce stress, manage emotions and mental health. The objective was to study the information exchange between symmetric electrodes across the hemispheres during meditation using functional connectivity (FC) measures. We investigate the changes in the coherence between EEG electrode pairs during the meditation practiced by long-term Brahmakumaris Rajyoga meditators with open eyes and during listening to music by controls as the comparable task. Two distinct FC measures derived from coherency, namely, magnitude squared coherence (MSC) and imaginary part of coherency (ICoh) are used to study the changes in interhemispheric coherence. During baseline conditions, higher MSC is found in meditators in frontocentral and centroparietal regions and higher |ICoh| globally in higher beta and gamma bands than controls. Further, in meditators, the MSC significantly increases in higher theta and alpha bands in the frontal and parietal ...
2020 IEEE 17th India Council International Conference (INDICON), 2020
Effects of meditation on electroencephalographic (EEG) activity are still being investigated desp... more Effects of meditation on electroencephalographic (EEG) activity are still being investigated despite decades of research. Neurophysiological correlation during meditation has been empirically postulated using different time and frequency domain entropy features of EEG. EEG has been recorded from fifteen Rajayoga meditators practiced by Prajapita Brahmakumaris World Spiritual University. Most of the meditators have shown increase in time domain fuzzy based entropy in frontal region during meditation. We have compared the data recorded during the peace and angelic meditation practices. The mean of the entropy values in each state is used to study the meditation and non-meditation states. Analysis has been carried out region wise. The frontal region shows significant increase in the entropy values during the meditative states.
TENCON 2021 - 2021 IEEE Region 10 Conference (TENCON), 2021
This study proposes an approach to classify the EEG into meditation and non-meditation segments u... more This study proposes an approach to classify the EEG into meditation and non-meditation segments using a long short-term memory (LSTM) based deep neural network (DNN) framework. Inter-subject classification performance is assessed on EEG recorded from fourteen long-term Rajayoga meditators. Common spatial pattern is used for feature extraction, and linear discriminant analysis is used for dimensionality reduction. The sequence of features thus obtained is fed to a LSTM based DNN, which employs a fully connected layer for classification. We have achieved inter-subject classification accuracies of 79.1 %, 86.5%, 91.0%, and 94.1% with the respective use of the alpha, beta, lower-gamma, and higher-gamma bands for classification. To the best of our knowledge, this is the first work to employ deep learning to distinguish between the brain's electrical activity during meditation and at rest.
2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC)
Meditation practices are considered mental training and have increasingly received attention from... more Meditation practices are considered mental training and have increasingly received attention from the scientific community due to their potential psychological and physical health benefits. We compared the EEG data recorded from long-term rajayoga practitioners during different meditative and non-meditative periods. Minimum variance modified fuzzy entropy (MVMFE) is computed for each EEG band for all channels of a given lobe. The means across all the channel entropy values were obtained and compared during meditative and non-meditative states. Meditators showed higher frontal entropy in the lower gamma band (25-45Hz) during the meditative states. Independent component analysis was applied to ensure that muscle or eye artifacts did not contribute to the gamma activity. Our results extend previous findings on the changes in entropy observed in long-term meditators during rajayoga practice. Gamma band in EEG is implicated in cognitive processes requiring high-level processing such as attention, learning, memory control, and retrieval. Gamma activity is also suggested as a potential biomarker for therapeutic progress in patients with clinical depression. Based on our findings, there is an excellent possibility to utilize the practice of meditation as a training tool to strengthen the neural circuits, where age-related degeneration is making its pathological impact.
Uploads
Papers by Kanishq Sharma