Abstract
Pain and touch have classically been considered two different sensory modalities. They are implemented by different types of receptors with different densities and receptive fields sizes and characterised by distinct ascending pathways which project in part to different cortical regions (e.g., Treede et al., 1999). This anatomical segregation is reflected by marked perceptual differences such as the opposite gradients of spatial acuity observed for tactile and nociceptive stimuli (e.g., Mancini et al., 2014). However, recent evidence has suggested a higher degree of integration at the cortical level between the sensory-discriminative aspects of touch and pain. For example, nociceptive somatotopic maps of the digits have been observed in contralateral SI (e.g., Mancini et al., 2012). Crucially, these maps appear highly aligned with those of non-painful tactile stimuli. This possibility raises the question of whether the mechanisms of spatial attention engaged during the processing of tactile and nociceptive stimuli are mediated by distinct or shared neural circuits. Top-down cognitive functions such as spatial attention are known to play a key role in shaping the neural and behavioural responses to painful and tactile stimuli. While recent studies have started to unravel the mechanisms responsible for tactile and nociceptive spatial selectivity, so far these processes have been investigated mostly independently in separate studies. The aim of this project is to compare directly the effects of spatial attention on tactile and nociceptive somatosensory information. Bringing these research fields together and understanding
the mechanisms of spatial attention in somatosensation is important not only to broaden our understanding of basic cognitive functions, but also to develop knowledge potentially transferable to clinical practice. Given the close relationship between attention and conscious experience, results of this project will orient the research on the influence of cognitive functioning on pain tolerance. We plan to combine different neuroimaging methods in a convergent manner to gather data with high temporal (i.e., ERPs) and spatial (i.e., fMRI) resolution, exploiting the different expertises present in our teams.