Affective Ratings of Vibrotactile Signals in Older Adults With and Without History of Stroke

Emerging research seeks to apply vibrotactile stimulation in physical therapy to improve diminished limb function. However, for these systems to be accepted, prospective users must find the stimulation tolerable or even pleasant. Prior studies on affective response to stimulation focus on healthy, younger users; older users of new therapeutic applications have different sensory perception than these younger users. Here we queried older adults with and without history of stroke to understand their experience of vibration on the arm at several amplitude-frequency settings and patterns. None of our stimuli were perceived as painful by participants, including two with allodynia who perceive some tactile stimuli as noxious. Individuals with history of stroke reported significantly lower valence ratings but higher arousal ratings than individuals without history of stroke. Lower amplitude stimulation was rated with lower arousal by all participants. Some participants expressed a preference for perceivable or strong stimulation. Reported sensations included tickling, tingling, and numbness.