Advanced meditators in the Zen tradition occasionally experience traumatic physical seizures accompanied by powerful, disruptive emotions, a development consistently taken by meditation masters as signs of progress toward enlightenment. Using data from LSD research, this paper suggests that these seizures are emerging birth-trauma memories. Interpreting these perinatal memories as memories of fetal impingement, it then turns to object-relations theory to study the effect of impingement and impingement-generated fear on ego-development in order to understand why embodied impingement memories should manifest in the ego-dissolving context of meditation. It argues that a coherent explanation for the manifestation of these symptoms can be had by combining insights from these two fields with the understanding of meditation and consciousness emerging in transpersonal psychology.