Characterization of Nociception Phenotype in Individuals With Intellectual Disability

STUDY DESCRIPTION: The study aims to evaluate the somatosensory response to innocuous and noxious stimuli in individuals with Intellectual Disability (ID) compared to healthy controls. OBJECTIVES: Primary Objective: To characterize brain activation patterns using electroencephalography (EEG) and cerebral functional-near-infrared spectroscopy (fNIRS) in response to innocuous and noxious stimulation in individuals with ID (ages, 8-30 years), compared with the brain activation pattern observed in healthy controls. We hypothesize that compared to healthy controls, individuals with ID will present decreases in oxygenated hemoglobin (measured by fNIRS) in pain responsive regions (e.g., secondary somatosensory cortex), in response to standardized noxious stimuli (heat, cold, and electrical). In addition, individuals with ID will also present smaller suppression of oscillation in alpha and beta frequencies (measured by EEG at central sites) in response to these stimuli. Exploratory Objective: To determine the relationship between brain activation patterns to innocuous and noxious stimuli with physiological and behavioral responses to the same stimuli, in individuals with ID. We hypothesize that decreased oxygenated hemoglobin in response to noxious stimuli in the secondary somatosensory cortex, as well as smaller suppression of oscillations in alpha and beta frequencies at central sites in individuals with ID will correlate with changes in heart rate, galvanic skin response and pupil dilation. In addition, we hypothesize that decreased oxygenated hemoglobin to noxious thermal and electrical stimuli in the secondary somatosensory cortex, as well as smaller suppression of oscillations in alpha and beta frequencies will also be associated with behavioral observations (e.g. vocal, social and changes in facial, body and extremities activity). ENDPOINTS: Primary Endpoints: 1. fNIRS response to innocuous and noxious stimuli: oxygenated and deoxygenated hemoglobin concentration measured in the secondary somatosensory cortex. 2. EEG response to innocuous and noxious stimuli: Alpha and beta oscillations measured at central sites (C3 and C4). 3. Physiological responses to innocuous and noxious stimulation (heart rate, respiratory rate, galvanic skin response, and pupillary changes). 4. Behavioral responses to noxious stimulation (e.g. vocal, social and changes in facial, body and extremities activity).