Improvements in perceptual discrimination from intensive meditation training can alter brain signals related to attention and perception, but only when the task difficulty is fixed rather than adjusted to match the person's improving ability. In two three-month meditation retreats, participants performed a continuous visual task while brain activity was recorded. When the target difficulty was held constant, training reduced declines in early sensory processing and shifted the timing of those brain signals. Changes in later processing stages correlated with better perceptual thresholds. No such brain changes occurred when task difficulty was increased to keep pace with participants' improving skill. The findings show that directed mental training can modify electrophysiological markers of attention and perception, depending on how task demands relate to the individual's capacity.
Sustained attention tasks often reduce the ability to discriminate goal-relevant stimuli over time. Intensive training in shamatha (focused-attention) meditation can improve perceptual discrimination of difficult-to-see visual stimuli. In two 3-month meditation retreats, participants performed a continuous performance task at three time points. In Retreat 1, the target difficulty was adjusted to match each participant's improving perceptual capacity, and no training effects on brain activity were observed. In Retreat 2, the target difficulty was held constant, leading to earlier onset of sensory brain signals and reduced performance decline over time. Changes in later processing stages correlated with improvements in perceptual threshold. The findings suggest that meditation-related improvements in perceptual discrimination can alter electrophysiological markers of attention and perception, but only when task demands allow discrimination capacity to exceed target difficulty.