?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Warping+Similarity+Space+in+Category+Learning+by+Human+Subjects%3A+The+Role+of+Task+Difficulty&rft.creator=Pevtzow%2C+Rachel&rft.creator=Harnad%2C+Stevan&rft.subject=Perceptual+Cognitive+Psychology&rft.description=In+innate+Categorical+Perception+(CP)+(e.g.%2C+colour+perception)%2C+similarity+space+is+%22warped%2C%22%0Awith+regions+of+increased+within-category+similarity+(compression)+and+regions+of+reduced%0Abetween-category+similarity+(separation)+enh+ancing+the+category+boundaries+and+making+categorisation%0Areliable+and+all-or-none+rather+than+graded.+We+show+that+category+learning+can+likewise+warp%0Asimilarity+space%2C+resolving+uncertainty+near+category+boundaries.+Two+Hard+and+two+Easy+texture%0Alearning+tasks+were+compared%3A+As+predicted%2C+there+were+fewer+successful+Learners+with+the+Hard+task%2C%0Aand+only+the+successful+Learners+of+the+Hard+task+exhibited+CP.+In+a+second+experiment%2C+the+Easy+task%0Awas+made+Hard+by+making+the+corrective+feedback+during+learn+ing+only+90%25+reliable%3B+this+too%0Agenerated+CP.+The+results+are+discussed+in+relation+to+supervised%2C+unsupervised+and+dual-mode+models%0Aof+category+learning+and+representation.The+world+is+full+of+things+that+vary+in+their+similarity+and%0Ainterconfusability.O+rganisms+must+somehow+resolve+this+confusion%2C+sorting+and+acting+upon+things%0Aadaptively.+It+might+be+important%2C+for+example%2C+to+learn+which+kinds+of+mushrooms+are+poisonous+and%0Awhich+are+safe+to+eat%2C+minimising+the+confusion+between+them+(Greco%2C+Cangelosi+%26+Harnad+1997).+%0A&rft.publisher=Department+of+Artificial+Intelligence%2C+Edinburgh+University&rft.contributor=Ramscar%2C+M.&rft.contributor=Hahn%2C+U.&rft.date=1997&rft.type=Book+Chapter&rft.type=NonPeerReviewed&rft.format=text%2Fhtml&rft.identifier=http%3A%2F%2Fcogprints.org%2F1607%2F1%2Fharnad97.textures.html&rft.identifier=++Pevtzow%2C+Rachel+and+Harnad%2C+Stevan++(1997)+Warping+Similarity+Space+in+Category+Learning+by+Human+Subjects%3A+The+Role+of+Task+Difficulty.++%5BBook+Chapter%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1607%2F