Relaxation meditation (Yoga Nidra) increased cerebral blood flow in posterior sensory and associative cortices, whereas the resting state of normal consciousness activated the executive attentional network.
Observational (n=9)
No
Does relaxation meditation (Yoga Nidra) alter cerebral blood flow distribution compared to the resting state of normal consciousness in young adults?
Meditation and resting states of normal consciousness are supported by characteristic patterns of neural activity, with meditation activating posterior sensory and associative cortices.
p-value: p=<0.001
The aim of the present study was to examine whether the neural structures subserving meditation can be reproducibly measured, and, if so, whether they are different from those supporting the resting state of normal consciousness. Cerebral blood flow distribution was investigated with the 15O-H20 PET technique in nine young adults, who were highly experienced yoga teachers, during the relaxation meditation (Yoga Nidra), and during the resting state of normal consciousness. In addition, global CBF was measured in two of the subjects. Spectral EEG analysis was performed throughout the investigations. In meditation, differential activity was seen, with the noticeable exception of V1, in the posterior sensory and associative cortices known to participate in imagery tasks. In the resting state of normal consciousness (compared with meditation as a baseline), differential activity was found in dorso-lateral and orbital frontal cortex, anterior cingulate gyri, left temporal gyri, left inferior parietal lobule, striatal and thalamic regions, pons and cerebellar vermis and hemispheres, structures thought to support an executive attentional network. The mean global flow remained unchanged for both subjects throughout the investigation (39+/-5 and 38+/-4 ml/100 g/min, uncorrected for partial volume effects). It is concluded that the (H2)15O PET method may measure CBF distribution in the meditative state as well as during the resting state of normal consciousness, and that characteristic patterns of neural activity support each state. These findings enhance our understanding of the neural basis of different aspects of consciousness.
Lou et al. (Fri,) conducted a observational in Healthy volunteers (yoga practitioners) (n=9). Relaxation meditation (Yoga Nidra) vs. Resting state of normal consciousness was evaluated on Regional cerebral blood flow (CBF) distribution differences (p=<0.001). Relaxation meditation (Yoga Nidra) increased cerebral blood flow in posterior sensory and associative cortices, whereas the resting state of normal consciousness activated the executive attentional network.