NEC Seminar: Friday, January 23rd, 9:00 AM
Speaker: John Wright
Advisor: Dr. Emily Graczyk
Abstract: Objects moving across the skin can indicate everything from the touch of a loved one, the crawling of a bug, or an object sliding from your grasp. Due to the wide variety of potential meanings of moving touch, the ability to quickly identify the speed, direction, and probable path of an object moving across the skin is crucial. Indeed, humans can deduce these characteristics using information encoded in the first hundred milliseconds of object contact. At this time, it is unclear the extent to which these abilities are retained in sensation restored via peripheral nerve stimulation (PNS). To investigate, we performed psychometric testing to examine the judgment of temporal order and continuity in two participants with upper extremity limb loss who have been implanted with 16-channel C-FINE cuffs around the median nerve in the residual limb. We also investigated the qualitative perception of movement across the skin using a mixed-methods qualitative interview paradigm. We found that while both participants could accurately perform temporal order and continuity judgments, the extent to which PNS-elicited sensations felt like moving touch varied greatly. Interview data suggested that the characteristics of the stimuli that influenced the perception of movement also differed. This information helps us better understand the qualitative experience of multi-contact PNS stimulation as well as the perceptual limits that may underlie stimulation paradigm development. This information could be leveraged to design better stimulation strategies to convey sensations such as object slippage or touch patterns common in affiliative or affective touch.