Kasamatsu and Hirai (1991)
Researched how the neurotransmitter serotonin can affect behavior by studying how sensory deprivation affects the brain. Studied monks who went on a pilgrimage. Found higher levels of serotonin in the brain when the monks began to talk about hallucinations.-Serotonin Monk Study
Kasamatsu and Hirai (1991) conducted a study on the effects of sensory deprivation on the brain. They selected 7 Buddhist monks who had been practicing meditation for more than 10 years and exposed them to an environment with complete sensory deprivation for 48 hours.
The researchers found that the monks started experiencing altered states of consciousness, which they described as hallucinations, euphoria, and feelings of transcendence. The monks also reported losing their sense of time and experiencing a heightened awareness of their own emotional and physical states.
Interestingly, Kasamatsu and Hirai also measured the monks’ brain activity during the 48-hour deprivation period and found changes in their brain waves. Specifically, the monks displayed a significant increase in alpha waves, which are associated with relaxation and meditation. They also showed a decrease in beta waves, which are linked to active problem-solving and decision-making.
Overall, the study suggests that sensory deprivation can lead to altered states of consciousness and changes in brain activity, particularly in individuals who have had extensive experience in meditation. The findings may have implications for understanding the neural mechanisms underlying meditation and mindfulness practices.