Somatosensation & CT-mediated affective touch across healthy and clinical populations

The present PhD thesis aimed to investigate the relevance of the C-tactile (CT) system across healthy and clinical populations of varying nature, initially providing an overview of tactile functions in the context of somatosensation and the theoretical framework of the Affective Touch Hypothesis, and consequently exploring its dysfunctions in physical and mental disorders in comparison to what is typically observed in healthy individuals, through the presentation of two experimental studies. In the first study, conducted on patients with Mild Cognitive Impairment due to Alzheimer’s Disease (AD), a multi-level alteration of the pleasant and soothing features of CT-optimal touch was identified as a prodromal marker of AD, providing the first indications of how the CT system degrades in conditions of pathological ageing, and offering a glimpse into the importance of affectionate interpersonal touch as a preserved resource in healthy ageing. In the second study, conducted on patients suffering from Fibromyalgia (FM), CT functions were assessed alongside other somatosensory functions and (neuro)psychological symptoms deemed indicative of the pathogenic processes hypothesized to underlie this chronic pain condition, providing evidence for a distinct FM subtype which manifests prevalently in the form of a severe psychosomatic disorder with multifaceted psychological disturbances, in the absence of any observable small-fiber dysfunctions. Overall, the findings strongly emphasize the utility and clinical relevance of integrating CT-mediated Affective Touch in the assessment and treatment of specific pathologies.