Five different meditation practices will be provided, all of which have been validated in prior research.

• The Body Scan practice consists of instruction in how to direct non-judgmental attention to different regions of the body
• The Mindful Breathing practice consists of focused attention on the breath and metacognitive monitoring and acceptance of discursive thoughts, negative emotions, and body sensations
• The Mindfulness of Discomfort practice consists of instruction in how to "zoom in" to deconstruct discomfort and map each feelings' spatial location, use mindful breathing to "zoom out" and broaden the field of awareness to include neglected sensory elements, and shift attention from unpleasant feelings to neutral/pleasant sensations or experiences
• The Savoring practice consists of instruction in identifying and amplifying pleasant memories
• The Loving-Kindness practice consists of instruction in cultivating feeling of warmth and compassion toward the self and others

To assess the acute anxiolytic effects of a brief mindfulness intervention during RT for brain tumor patients with mask anxiety.

Acute anxiety during RT will be measured each RT visit with an individual item ("How nervous, anxious or on edge do you feel right now?" scored on a 0-10 scale) derived from the Generalized Anxiety Disorder 2-item (GAD-2) scale, "0" meaning "Not at All" and "10" meaning "Very Much") measured before and after RT. The change from before to after RT will be averaged over all RT visits.

To assess the distal anxiolytic effects of a brief mindfulness intervention during RT for brain tumor patients with mask anxiety.

Anxiety in everyday life will be measured using the total score of the Generalized Anxiety Disorder 2-item (GAD-2) scale prior to RT (minumum value 0, maximum value 6, score of 3 or higher considered clinical.) This will be measured once a week during RT.