A vibrotactile behavioral battery for investigating somatosensory processing in children and adults

Abstract

The cortical dynamics of somatosensory processing can be investigated using vibrotactile psychophysics. It has been suggested that different vibrotactile paradigms target different cortical mechanisms, and a number of recent studies have established links between somatosensory cortical function and measurable aspects of behavior. The relationship between cortical mechanisms and sensory function is particularly relevant with respect to developmental disorders in which altered inhibitory processing has been postulated, such as in ASD and ADHD. In this study, a vibrotactile battery consisting of nine tasks (incorporating reaction time, detection threshold, and amplitude- and frequency discrimination) was applied to a cohort of healthy adults and a cohort of typically developing children to assess the feasibility of such a vibrotactile battery in both cohorts, and the performance between children and adults was compared. These results showed that children and adults were both able to perform these tasks with a similar performance, although the children were slightly less sensitive in frequency discrimination. Performance within different task-groups clustered together in adults, providing further evidence that these tasks tap into different cortical mechanisms, which is also discussed. This clustering was not observed in children, which may be potentially indicative of development and a greater variability. In conclusion, in this study, we showed that both children and adults were able to perform an extensive vibrotactile battery, and we showed the feasibility of applying this battery to other (e.g., neurodevelopmental) cohorts to probe different cortical mechanisms.

Keywords: Behavioral; GABA; HA; ISI; ITI; LD2/LD3; Pediatric; Somatosensory; Stimulator; TDC; Vibrotactile; amplitude discrimination – dual-site adaptation; amplitude discrimination – no adaptation; amplitude discrimination – single-site adaptation; cRT; choice reaction time task; dAD; dD; dynamic detection threshold task; healthy adults; interstimulus interval; intertrial interval; left digit 2 and left digit 3; nAD; sAD; sD; sRT; sequential frequency discrimination; simple reaction time task; simultaneous frequency discrimination; smFD; sqFD; static detection threshold task; typically developing children.