As predicted in Hypothesis 4, the meditators' working memory was enhanced significantly more at postintervention than that of the nonmeditators, although there was only a small-to-medium effect size for the time by group interaction. This is a new finding, without precedent in the literature. It is particularly noteworthy, as it suggests that mindfulness practice may increase working memory capacity, and may thus have widespread application as an intervention in a broad range of psychological areas. Furthermore, it was found in the present study to mediate the meditators' postintervention increase in mindfulness, as measured by their improved scores on the Mindful Attention Awareness Scale (MAAS). The implications of this will be discussed in a later section.