Habituation: effects of regular and stochastic stimulation

Abstract

S U M MARY The different effects of regular and stochastic stimulation on the flexor reflex of patients with the spinal cord totally divided and of normal subjects and on the blink reflex of normal subjects were studied.When the cutaneous stimulus was above but less than twice threshold, with regular stimulation habituation occurred; with stochastic stimulation, habituation either did not occur or it was minimal. Stochastic stimulation was at random stimulus intervals or with random stimulus intensities.When stimulus intensity was around threshold, habituation occurred with both kinds of stimulation, the response to stimulation soon ceasing to occur. When stimulus intensity was greater than twice threshold, habituation did not occur with both kinds of stimulation.When regular stimulation was given after the response had ceased to occur, extinction of the response beyond zero occurred.When a dishabituating stimulus was repeatedly applied in a regular manner, habituation to the dishabituating stimulus occurred.With regular and stochastic stimulation given as conditioning and test series, it was seen that stochastic stimulation caused, in addition to the short-term excitatory effect, the same long-term cumulative depressing effect on excitability as did regular stimulation.

Facilitation of the withdrawal reflex by repeated transcutaneous electrical stimulation: an experimental study on central integration in humans

“…Habituation is most pronounced for low stimulus intensities (Dimitrijevic et al 1972), as observed in the present study. Alternatively, the tendency for re¯exes of lower amplitude to occur could also re¯ect a lowering of the arousal level as the volunteers adapt to experimental conditions.…”

Suppression of flexor reflex by transcutaneous electrical nerve stimulation in spinal cord injured patients

“…It was shown that this pattern of repetitive reflex stimulation prevents habituation of the flexor reflex responses. 6,12,14,24 The successive reflex responses obtained before TENS application and those elicited after placebo-TENS in this study did not show a significant tendency to decrease on repetitive stimulation. We may therefore conclude that the observed decrease of flexor reflex responses following TENS application to the area of the sural nerve cannot be attributed to the process of habituation.…”

Introducing the reflex probability maps in the quantification of nociceptive withdrawal reflex receptive fields in humans

“…Similar results were already reported in previous reflex studies, where it was discover that a proper selection of the stimulation parameters, e.g. random inter-stimulus intervals, stimulation of different sites and varying stimulation intensities, can prevent reflexes from habituating ( (Dimitrijević et al, 1972;Granat et al, 1991).…”