The Pain Matrix Reloaded . 1 A Salience Detection System for the Body

word count: 247) 1 Neuroimaging and neurophysiological studies have shown that nociceptive stimuli 2 elicit responses in an extensive cortical network including somatosensory, insular 3 and cingulate areas, as well as frontal and parietal areas. This network, often 4 referred to as the “pain matrix”, is viewed as representing the activity by which the 5 intensity and unpleasantness of the percept elicited by a nociceptive stimulus are 6 represented. However, recent experiments have reported (i) that pain intensity can 7 be dissociated from the magnitude of responses in the “pain matrix”, (ii) that the 8 responses in the “pain matrix” are strongly influenced by the context within which the 9 nociceptive stimuli appears, and (iii) that non-nociceptive stimuli can elicit cortical 10 responses with a spatial configuration similar to that of the “pain matrix”. For these 11 reasons, we propose an alternative view of the functional significance of this cortical 12 network, in which it reflects a system involved in detecting, orienting attention 13 towards, and reacting to the occurrence of salient sensory events. This cortical 14 network might represent a basic mechanism through which significant events for the 15 body‟s integrity are detected, regardless of the sensory channel through which these 16 events are conveyed. This function would involve the construction of a multimodal 17 cortical representation of the body and nearby space. Under the assumption that this 18 network acts as a defensive system signaling potentially damaging threats for the 19 body, emphasis is no longer on the quality of the sensation elicited by noxious stimuli 20 but on the action prompted by the occurrence of potential threats. 21 22