?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Features+of+the+Representation+Space+for+3D+Objects&rft.creator=Edelman%2C+S&rft.creator=Buelthoff%2C+H+H&rft.creator=Buelthoff%2C+I&rft.subject=Cognitive+Psychology&rft.description=To+explore+the+nature+of+the+representation+space+of+3D+objects%2C+we+studied+human+performance+in+forced-choice+classification+of+objects+composed+of+four+geon-like+parts%2C+emanating+from+a+common+center.+The+two+class+prototypes+were+distinguished+by+qualitative+contrasts+(bulging+vs.%5C+waist-like+limbs).+Subjects+were+trained+to+discriminate+between+the+two+prototypes+(shown+briefly%2C+from+a+number+of+viewpoints%2C+in+stereo)+in+a+1-interval+forced-choice+task%2C+until+they+reached+a+90%25+correct-response+performance+level.+In+the+first+experiment%2C+11+subjects+were+tested+on+shapes+obtained+by+varying+the+prototypical+parameters+both+orthogonally+(Ortho)+and+in+parallel+(Para)+to+the+line+connecting+the+prototypes+in+the+parameter+space.+For+the+eight+subjects+who+performed+above+chance%2C+the+error+rate+increased+with+the+Ortho+parameter-space+displacement+between+the+stimulus+and+the+corresponding+prototype+(the+effect+of+the+Para+displacement+was+marginal).+Clearly%2C+the+parameter-space+location+of+the+stimuli+mattered+more+than+the+qualitative+contrasts+(which+were+always+present).+To+find+out+whether+both+prototypes+or+just+the+nearest+neighbor+of+the+test+shape+influenced+the+decision%2C+in+the+second+experiment+we+tested+18+new+subjects+on+a+fixed+set+of+shapes%2C+while+the+test-stage+distance+between+the+two+classes+assumed+one+of+three+values+(Far%2C+Intermediate%2C+and+Near).+For+the+13+subjects+who+performed+above+chance%2C+the+error+rate+(on+physically+identical+stimuli)+in+the+Near+condition+was+higher+than+in+the+other+two+conditions.+The+results+of+the+two+experiments+contradict+the+prediction+of+theories+that+postulate+exclusive+reliance+on+qualitative+contrasts%2C+and+support+the+notion+of+a+metric+representation+space%2C+with+the+subjects'+performance+determined+by+distances+to+more+than+one+reference+point+or+prototype.&rft.date=1996&rft.type=Preprint&rft.type=NonPeerReviewed&rft.format=application%2Fpostscript&rft.identifier=http%3A%2F%2Fcogprints.org%2F564%2F2%2F199710006.ps&rft.identifier=++Edelman%2C+S+and+Buelthoff%2C+H+H+and+Buelthoff%2C+I++(1996)+Features+of+the+Representation+Space+for+3D+Objects.++%5BPreprint%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F564%2F