Figure 1.

Experimental procedures across time. First column, Psychophysical training session: Subjects first came in for psychophysical training. In this session, subjects were familiarized with visual analog scales, the range of thermal stimulation, and thermal stimulation paradigm used in the subsequent MRI sessions. Second column, MRI session 1: In the first two blocks, subjects were asked to reduce movement and keep eyes closed (rest). A heat (49°C) and neutral (35°) series were randomly presented in one of two blocks. Before anatomical acquisition, subjects were instructed to “begin meditating by focusing on the sensations of the breath.” Subjects continued to attend to the breath during a block of noxious stimulation (49°C) or neutral (35°). Pain ratings were assessed after each block. Third column: The 4 d (20 min/d) meditation intervention. Subjects were taught to focus on the changing sensations of the breath. They were taught that discursive thoughts were to be acknowledged without affective reaction and “let go” by redirecting their focus back on breath sensations. In sessions 3 and 4, sounds of the MRI scanner were introduced to familiarize subjects with the MRI environment. The fourth column describes the MRI session 2 (after meditation training). In the first four blocks, subjects were instructed to reduce movement and close their eyes (rest). Two heat (49°C) and two neutral (35°C) blocks were randomly administered. Before anatomical acquisition, subjects were instructed to “begin meditating by focusing on the sensations of the breath.” Subjects continued to meditate across two blocks of noxious stimulation (49°C) and neutral (35°C). Pain ratings were assessed after each block.