When we are not focused on a task, mind-wandering or just idling, specific regions of the brain such as medial pre frontal cortex, angular gyrus, hippocampus become activated and are called the default mode network. This is thought to be important for self referential thought, memory and future planning. It has been mapped with resting state fMRI, and also visible with EEG/MEG, PET and is thought to be modulated by TMS. The default mode network is linked to mood disorders, neurodegeneration, aging and creativity. Its activity in disease disorders is significant.
For example in aging, there is thought to be a age related default mode network fragmentation and in Alzheimer’s there is known to be reduced functioanl connectivity especially in the medial prefrontal cortex.
In older adults, a default mode network that is fragmented points towards cognitive decline,, Mild cognitive impairment or Alzheimer’s disease. A fragment network is one that do not fire together or is less integrated with frontoparietal control or salience network.
Will this be a biomarker of aging ?
