Ventral attention network

The ventral attention network (VAN) or task-negative network (TNN) is one of two sensory orienting systems in the human brain, the other being the dorsal attention or task-positive network. Its main function is to reorient attention towards salient stimuli. The VAN is considered to be involved mostly, if not entirely, in involuntary actions. The neural network is right hemisphere lateralized and includes the right temporal-parietal junction and the right ventral frontal cortex. This system shows activity increases upon detection of salient targets, especially when they appear in unexpected locations. Activity increases also are observed in the ventral system after abrupt changes in sensory stimuli, at the onset and offset of task blocks , and at the end of a completed trial.