By John M. de Castro, Ph.D.
“Regular meditators activated fewer brain regions than non-meditators in order to achieve the same performance during an attentional task. This is evidence that meditation training can increase brain efficiency in attention and impulse control.” – Elisa Kozasa
One of the primary effects of meditation training is an improvement in the ability to pay attention to the task at hand and ignore interfering stimuli. This is an important consequence of meditation training and produces improvements in thinking, reasoning, and creativity. These improvements are known to occur due to the effects of meditation training on the brain. It appears That meditation increases the size, connectivity, and activity of areas of the brain that are involved in paying attention.
A common method to study the activity of the nervous system is to measure the electrical signal at the scalp above brain regions. Changes in this activity are measurable with mindfulness training. One method to observe information processing in the brain is to measure the changes in the electrical activity that occur in response to specific stimuli. These are called evoked potentials or ERPs. The signal following a stimulus changes over time. The fluctuations of the signal after specific periods of time are thought to measure different aspects of the nervous system’s processing of the stimulus.
The P3 response in the evoked potential (ERP) occurs around a quarter of a second following the stimulus presentation. It is a positive change that is maximally measured over the central frontal lobe. The P3 response has been associated with the engagement of attention. So, the P3 response is often used as a measure of brain attentional processing with the larger the positive change the greater the attentional focus. The N2 response in the evoked potential (ERP) generally precedes the P3 response. It is a negative change that is maximally measured over the frontal lobe. The N2 response has been associated with the engagement of attention to a new or novel stimulus. So, the N2 response is often used as a measure of brain attentional processing with the large the negative changes an indication of greater discrimination of new stimuli.
In today’s Research News article “Event-related potential correlates of mindfulness meditation competence”
Atchley and colleagues measure the P3 and N2 responses in naive, novice (less than 1000 hours of experience), or experienced (more than 5000 hours of experience) meditators in an attempt to measure the effects of amount of meditation practice on brain function. The participants listened to a series of tones. ERPs were measured under two conditions. In the first condition they were asked to push a button whenever and infrequent high-pitched tome occurred. In the second condition they meditated by counting breaths and were asked to ignore the tones.
They found that all groups had lower P3 responses in the breath counting condition, but both groups of meditators had greater reductions in the response than the naïve participants. This suggested that meditation training improves the ability to screen out distracting or irrelevant stimuli. Meditators also had a greater reduction in N2 amplitude than the naïve group in the breath counting condition. This suggests that meditation training improves the ability to react less to new stimuli and thereby have an improved ability to ignore new stimuli and not react to novelty.
It is interesting that no differences were found between novice and experienced meditators. But, their definition of a novice meditator as having less than 1000 hours of experience may actually have produced a group of fairly experienced meditators as the novice group averaged 2.4 years of meditation experience. Perhaps with a less experienced group, differences with experienced meditators may have been seen.
Regardless, the results demonstrate that meditation reshapes the brain to improve the ability to pay attention to the task at hand and ignore irrelevant and/or distracting information. So, shape the brain to improve attention with meditation.
“To cultivate attention, it is sufficient to rely on one basic principle: return again and again to what is already there. Our body knows how to sit straight. Our breath knows how to flow naturally. Our mind and our hearts already know how to rest. In this practice, we simply allow them to do that. Whenever there is a disturbance, we return to what is already there.” – Ken McLeod
CMCS – Center for Mindfulness and Contemplative Studies