When our mind wanders, a part of our brain called default network starts to work. This default network is a brain system that includes part of the medial temporal lobe, medial prefrontal cortex and the posterior cingulate cortex.
Even though there are some opposite views about its function and part of it is unknown, some neuroscientists believe that this network is responsible for day dreaming, which is fundamental in the creative process.
The default network is also associated with the retrieval of memories, registering certain emotions, the capacity of assessing other points of view, and the ability to envision the future.
This area seems to be activated when we are reflecting and focused on our internal thoughts. This takes place when we eliminate distractions coming from the external environment.
It seems to be quite useful to have mind wandering moments for a number of reasons. These moments of thinking and reflection allow the brain to slow down, let's say a moment of rest, to allow the functions mentioned above which are very important in our daily living.
If we were to utilize the brain in full motion, i.e. absorbing information, comparing, making decisions etc., all day, then the consumption of energy would be so great that we would very easily be quite exhausted.
As adults, we spend 12% of the time imagining the future and this default network assists us in this process. However, how we will feel about a particular decision in the future is quite impossible to predict as some of the decisions we make today, may be clouded by how we are feeling today, which is a very interesting finding.
Some studies have shown that in young people, the activity in the default network decreases significantly or shuts down when they are given any other particular task to do or think about. In this case other areas of the brain become active. In older adults, however, this network keeps functioning and even more in people with Alzheimer's.
The explanation may well be as follows: As we get older and our memory ability diminishes, this network seems to remain active to compensate for the loss of memory that occurs in other regions of the brain to which the default network is connected.
