Non-dual awareness and sensory processing in meditators: Insights from startle reflex modulation

Startle modulation, specifically habituation and prepulse inhibition (PPI), reflects early sensory processing in the brain. In a comparison of regular meditators (32 individuals) and meditation-naïve individuals (36 individuals), no significant group differences emerged in either habituation or PPI. However, among meditators, those who reported being able to sustain non-dual awareness during practice (18 individuals) showed significantly greater PPI than those who could not (14 individuals). These results suggest that subjective differences in meditation experience may relate to distinct sensory processing characteristics.

Study at a glance

Abstract

Startle modulation paradigms, namely habituation and prepulse inhibition (PPI), can offer insight into the brain's early information processing mechanisms that might be impacted by regular meditation practice. Habituation refers to decreasing response to a repeatedly-presented startle stimulus, reflecting its redundancy. PPI refers to response reduction when a startling stimulus "pulse" is preceded by a weaker sensory stimulus "prepulse" and provides an operational measure of sensorimotor gating. Here, we examined habituation and PPI of the acoustic startle response in regular meditators (n = 32), relative to meditation-naïve individuals (n = 36). Overall, there was no significant difference between meditators and non-meditators in habituation or PPI, but there was significantly greater PPI in meditators who self-reported being able to enter and sustain non-dual awareness during their meditation practice (n = 18) relative to those who could not (n = 14). Together, these findings suggest that subjective differences in meditation experience may be associated with differential sensory processing characteristics in meditators.