▁from ▁its ▁database , ▁and ▁then ▁sends ▁the ▁associated ▁output ▁in ▁that ▁sequence . ▁The ▁other ▁model ▁is ▁an ▁art ic ulated ▁emulator . ▁This ▁model ▁requires ▁that ▁for ▁each ▁significant ▁sensor ▁of ▁the ▁human ▁mus cul os ke let al ▁system ▁there ▁is ▁a ▁group ▁of ▁neur ons ▁with ▁a ▁parallel ▁firing ▁frequency ▁within ▁the ▁emulator . ▁These ▁groups ▁of ▁neur ons ▁would ▁receive ▁the ▁same ▁input ▁as ▁that ▁being ▁sent ▁to ▁their ▁corresponding ▁part ▁of ▁the ▁mus cul os ke let al ▁system . ▁For ▁example , ▁when ▁raising ▁one ’ s ▁hand ▁signals ▁will ▁be ▁sent ▁to ▁neur ons ▁responsible ▁for ▁w rist , ▁el bow , ▁and ▁shoulder ▁angles ▁and ▁arm ▁angular ▁in ert ia . ▁ ▁Reg ard less ▁of ▁this ▁structure ▁both ▁systems ▁will ▁grow ▁and ▁change ▁over ▁time . ▁This ▁is ▁due ▁to ▁constant , ▁fl uct u ating ▁noise ▁from ▁the ▁environment ▁and ▁the ▁fact ▁that ▁the ▁body ▁changes ▁over ▁time . ▁G row ing ▁lim bs ▁and ▁mus cles ▁result ▁in ▁changes ▁in ▁both ▁required ▁input ▁commands ▁and ▁the ▁resulting ▁output . ▁This ▁requires ▁a ▁degree ▁of ▁pl astic ity ▁in ▁the ▁em ul ators . ▁Em ul ators ▁are ▁thus ▁contin ually ▁updating , ▁always ▁receiving ▁the ▁resulting ▁output ▁from ▁the ▁mus cul os ke let al ▁system ▁from ▁an ▁input ted ▁command ▁and ▁comparing ▁it ▁to ▁its ▁own ▁output . ▁It ▁is ▁likely ▁that ▁this ▁is ▁accomplished ▁through ▁Kal man ▁Filter . ▁Complete ▁correction ▁from ▁the ▁difference ▁in ▁outputs , ▁however ,