abstract Danilo Bzdok

Danilo Bzdok (Aachen University, Germany and INRIA/Neurospin, Paris, FR)

Data-led approaches to the default mode of human brain function

15 years ago neuroscientists discovered a unique brain network. The so-called default-mode network (DMN) appeared to be exclusive in decreasing neural activity consistently during experimental tasks. It was later even argued that this network is systematically anti-correlated with brain regions active during task performance. This was recently challenged by repeated reports of brain regions exhibiting both task-constrained and task-unconstrained increases in neural activity. On the one hand, the DMN is now believed to be mostly, but not exclusively, active during absent external stimulation. On the other hand, the DMN is today known to also increase neural activity consistently during a small set of complex cognitive tasks. This includes the contemplation of others’ and one’s own mind states, as well as scene construction processes when envisioning past, fictitious, and future events. It was speculated that the human brain might have evolved to, by default, predict environmental events using mental imagery. Constructing detached probabilistic scenes could thus influence perception and behavior by estimating saliency and action outcomes. This would invigorate a possible relationship between the physiological baseline of the human brain and an introspective psychological baseline. The DMN defies our neuroscientific intuitions and challenges established methodology. This brain network likely represents a physiological instantiation of a human beings' default mental repertoire, the nature of which remains largely obscure.