title: Interstimulus interval effects on habituation of flexor withdrawal activity mediated by the functionally transected human spinal cord.
abstract: The habituation of flexor withdrawal activity mediated by the functionally transected human spinal cord was investigated as a function of a wide range of different temporal intervals among the repetitive cutaneous stimuli. Nine patients with a chronic, transverse lesion of the cervical spinal cord were submitted to four daily habituation training series involving interstimulus intervals of either 1, 5, 25, or 125 seconds. The stimulus consisted of a 40-msec pulse train applied through surface electrodes to a midplantar site, and the response was expressed in terms of the goniometrically recorded dorsiflexion of the ankle. A reliable degree of habituation was found for the series involving the 1- and 5-second intervals. However, holding constant the number of stimuli involved in the comparisons, no habituation was found for the series involving intervals of 25 and 125 seconds.
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae; D004558:Electric Stimulation; D004576:Electromyography; D006185:Habituation, Psychophysiologic; D006801:Humans; D007866:Leg; D008297:Male; D009132:Muscles / Q000503:physiopathology; D012018:Reflex; D013119:Spinal Cord Injuries / Q000503:physiopathology / Q000534:rehabilitation*