Somatosensation in the Brain: A Theoretical Re-evaluation and a New Model.

The somatosensory system is important for many functions, such as tactile recognition, the perception of our body, and motor actions. We present a comprehensive review of the human and animal literature on somatosensory processing over the past 10 years and evaluate how well existing models can accommodate the new observations. Based on these observations and a survey of the brain structures involved in somatosensation, we suggest that a new model is needed that describes multiple networks involved in separate subfunctions. These networks are highly interconnected and often multimodal in nature. The model includes basic somatosensory processing and five higher-order networks involved in haptic object recognition and memory, body perception, body ownership, affective processing, and action.