▁vest ib ular ▁system ▁is ▁not ▁responsible ▁for ▁' bra king ' ▁the ▁after effect . ▁Instead , ▁in ▁the ▁first ▁AF TER ▁trial ▁( when ▁the ▁after - effect ▁is ▁the ▁strong est ) ▁an ▁increase ▁in ▁leg ▁EM G ▁activity ▁is ▁observed ▁for ▁all ▁subjects . ▁This ▁increase ▁is ▁generated ▁un cons ci ously ▁and ▁before ▁foot - s led ▁contact . ▁The ▁' bra king ' ▁of ▁the ▁after - effect ▁is ▁therefore ▁an ▁anticip atory ▁process , ▁rather ▁than ▁being ▁triggered ▁by ▁an ▁external ▁threat : ▁the ▁central ▁nerv ous ▁system ▁anticip ates ▁that ▁the ▁after - effect ▁will ▁occur ▁and ▁that ▁it ▁will ▁threaten ▁our ▁balance , ▁and ▁generates ▁mechan isms ▁to ▁deal ▁with ▁the ▁threat . ▁When ▁ste pping ▁onto ▁a ▁station ary ▁es cal ator , ▁anticip atory ▁motor ▁mechan isms ▁prevent ▁us ▁from ▁falling ▁by ▁at ten u ating ▁the ▁after - effect . ▁ ▁See ▁also ▁ ▁References ▁▁ ▁Category : Ill us ions ▁Category : M ot or ▁control <0x0A> </s> ▁Esc all onia ▁b if ida , ▁the ▁clo ven ▁g um ▁box , ▁is ▁an ▁ever green ▁shr ub ▁or ▁small ▁tree ▁in ▁the ▁family ▁Esc all onia ceae . ▁It ▁is ▁native ▁to ▁Brazil ▁and ▁Uruguay . ▁ ▁It ▁can ▁grow ▁up ▁to ▁ ▁high ▁and ▁ ▁broad , ▁and ▁has ▁dark ▁green ▁sh iny ▁leaves ▁which ▁are ▁ 2 ▁to ▁ 7   cm ▁long ▁and ▁ 0 . 8 ▁to ▁ 2   cm ▁wide . The ▁pure