ISSN:
1432-1106
Keywords:
Vestibular habituation
;
Velocity step
;
Interstimulus interval
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary In order to clarify the problem of which stimulus parameters affect vestibular habituation, a group of cats was submitted to repeated velocity steps involving changes in either the step amplitude or the interval between two consecutive steps. In the first two experiments, the protocol was the same as in a previous study which used steps of 160°/s separated by 60 s, except that the steps were of 80°/s and 16°/s. In the remaining experiments the step amplitude was kept constant (160°/s) and the interstimulus interval was changed: each step was delivered either immediately after the reversal of the nystagmus elicited by the preceding step (only a few beats in the reversed direction were allowed to occur) or immediately before (no beats in the reversed direction). Vestibular habituation was found to occur in both experiments of the first series. Nevertheless, the marked initial suppression of the response, that was reported as one aspect of vestibular habituation to steps of 160°/s, was clearly present when steps of 80°/s were used, but was not as clear when the step amplitude was reduced to 16°/s. The experiments of the second series showed that a typical vestibular habituation still occurs when steps are delivered just after the reversal of nystagmus. On the contrary, no habituation was observed when steps preceded the reversal of nystagmus. It was concluded that the presence of an anticompensatory phase is interpreted by the central nervous system as a sign that the response evoked in a reflex way is functionally meaningless or even detrimental. An habituation process is then started to suppress the response.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00237660
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