Authors: Kieran C.R. Fox, R. Nathan Spreng, Melissa Ellamil, Jessica R. Andrews-Hanna, Kalina Christoff
Title: The wandering brain: Meta-analysis of functional neuroimaging studies
of mind-wandering and related spontaneous thought processes
Summary: Thinking about the most common effects on the brain from meditation will lead you into an area that psychologists call spontaneous thoughts. These are defined as thoughts and ideas that seem to come out of nowhere, and don’t necessarily have any obvious relationship to a specific task you may be undertaking. Meditation scientists have long considered that the most popular forms of secular meditation lower activity in regions of the brain known as the Default Mode Network (DMN). The DMN is strongly connected with, self reflection, thoughts about relationships with others, memories of the past and our ability to project into the future. It is also the home to our mind wandering or drifting.
Mind wandering can increase under certain conditions and has been linked to a number of long term mental health problems including anxiety and depression. Many forms of meditation reduce activity in the parts of the DMN known to support spontaneous thoughts and mind wandering. This can be a great help to people that have problems concentrating or are troubled by negative or challenging thoughts. The research by Fox and colleagues undertook a review of 24 functional neuroimaging studies looking into mind wandering/spontaneous thought. Results confirmed that well established centres in the DMN (medial prefrontal cortex, posterior cingulate cortex, medial temporal lobe, and bilateral inferior parietal lobule) were associated with mind wandering. However it was evident that a number of other brain regions were also engaged. The significance of the study was that, spontaneous thought cannot be regarded as universally linked to a limited number of centres in the DMN. A range of regions in different networks appear to be instrumental to spontaneous thought and mind wandering.
The implication for meditation practitioners and researchers is that the apparent act of suppression or restriction of activity in the DMN cannot be seen in a narrow context and may have broader implication for a number of interrelated processes.