Ashar · Social cognitive and affective neuroscience 2021 · randomized placebo-controlled trial · n=57

Effects of compassion training on brain responses to suffering others.

Level 2 - randomized trial

Three-arm randomized placebo-controlled trial

PubMed 33948660 · doi:10.1093/scan/nsab052 · record verified 2026-08-26

What was done

In a three-arm, placebo-controlled randomized trial with 57 participants, researchers evaluated a 4-week smartphone-delivered compassion meditation (CM) program against two comparators: (1) a placebo condition presented as the hormone oxytocin, and (2) a condition controlling for familiarity with suffering others. Brain activity was assessed using fMRI before and after the intervention while participants listened to compassion-eliciting narratives describing suffering others.

What was found

CM increased brain activation in the medial orbitofrontal cortex (mOFC) relative to the familiarity control condition (p < 0.05, family-wise error rate corrected). Within the CM group, increased mOFC activation positively correlated with increases in compassion-related feelings and attributions (r = 0.50, p = 0.04). Relative to placebo, the CM group showed increased mOFC activity only at an uncorrected threshold (p < 0.001, 10 contiguous voxels).

Why it matters

This trial identifies the medial orbitofrontal cortex as a neural mechanism of compassion meditation distinct from familiarity with suffering, though differences compared to placebo were modest and did not survive family-wise error correction.

Limits

The sample size is small (N = 57 split across three arms, averaging 19 per group). Contrast with the placebo group was only detectable at an uncorrected threshold. The abstract does not report participant demographics or long-term retention of neural changes.