?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Symbols+are+not+uniquely+human&rft.creator=Ribeiro%2C+Sidarta&rft.creator=Loula%2C+Angelo&rft.creator=Ara%C3%BAjo%2C+Ivan&rft.creator=Gudwin%2C+Ricardo&rft.creator=Queiroz%2C+Joao&rft.subject=Language&rft.subject=Ethology&rft.subject=Computational+Neuroscience&rft.subject=Behavioral+Neuroscience&rft.subject=Theoretical+Biology&rft.subject=Animal+Behavior&rft.subject=Neurolinguistics&rft.subject=Philosophy+of+Language&rft.subject=Neural+Modelling&rft.subject=Animal+Cognition&rft.subject=Comparative+Psychology&rft.subject=Artificial+Intelligence&rft.subject=Learnability&rft.subject=Epistemology&rft.description=Modern+semiotics+is+a+branch+of+logics+that+formally+defines+symbol-based+communication.+In+recent+years%2C+the+semiotic+classification+of+signs+has+been+invoked+to+support+the+notion+that+symbols+are+uniquely+human.+Here+we+show+that+alarm-calls+such+as+those+used+by+African+vervet+monkeys+(Cercopithecus+aethiops)%2C+logically+satisfy+the+semiotic+definition+of+symbol.+We+also+show+that+the+acquisition+of+vocal+symbols+in+vervet+monkeys+can+be+successfully+simulated+by+a+computer+program+based+on+minimal+semiotic+and+neurobiological+constraints.+The+simulations+indicate+that+learning+depends+on+the+tutor-predator+ratio%2C+and+that+apprentice-generated+auditory+mistakes+in+vocal+symbol+interpretation+have+little+effect+on+the+learning+rates+of+apprentices+(up+to+80%25+of+mistakes+are+tolerated).+In+contrast%2C+just+10%25+of+apprentice-generated+visual+mistakes+in+predator+identification+will+prevent+any+vocal+symbol+to+be+correctly+associated+with+a+predator+call+in+a+stable+manner.+Tutor+unreliability+was+also+deleterious+to+vocal+symbol+learning%3A+a+mere+5%25+of+%E2%80%9Clying%E2%80%9D+tutors+were+able+to+completely+disrupt+symbol+learning%2C+invariably+leading+to+the+acquisition+of+incorrect+associations+by+apprentices.+Our+investigation+corroborates+the+existence+of+vocal+symbols+in+a+non-human+species%2C+and+indicates+that+symbolic+competence+emerges+spontaneously+from+classical+associative+learning+mechanisms+when+the+conditioned+stimuli+are+self-generated%2C+arbitrary+and+socially+efficacious.+We+propose+that+more+exclusive+properties+of+human+language%2C+such+as+syntax%2C+may+derive+from+the+evolution+of+higher-order+domains+for+neural+association%2C+more+removed+from+both+the+sensory+input+and+the+motor+output%2C+able+to+support+the+gradual+complexification+of+grammatical+categories+into+syntax.&rft.publisher=Elsevier&rft.date=2006&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F5251%2F1%2FRibeiro_Loula_etal-2006-Symbols.pdf&rft.identifier=++Ribeiro%2C+Sidarta+and+Loula%2C+Angelo+and+Ara%C3%BAjo%2C+Ivan+and+Gudwin%2C+Ricardo+and+Queiroz%2C+Joao++(2006)+Symbols+are+not+uniquely+human.++%5BJournal+(Paginated)%5D++++(In+Press)++&rft.relation=http%3A%2F%2Fcogprints.org%2F5251%2F