?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Mismatch+negativity+(MMN)+is+altered+by+directing+attention&rft.creator=OADES%2C+Robert+D.&rft.creator=DITTMANN-BALCAR%2C+Alexandra&rft.subject=Neurophysiology&rft.subject=Perceptual+Cognitive+Psychology&rft.subject=Psychophysics&rft.description=Introduction%3A+MMN+is+a+negative+component+resulting+from+the+difference+in+event-related+potential+(ERP)+waveforms+elicited+by+a+standard+and+a+deviant+stimulus.+It+is+usually+studied+in+the+absence+of+attentional+requirements.+%0A%0AMethod%3A+Here+we+compare+this+measure+of+perceptual+comparison+in+a+nontask+situation+(3+tones+presented)+with+that+obtained+in+a+task+requiring+focussed+attention+and+response+to+the+third+tone.+Subjects+were+9+male+and+16+female+healthy+volunteers+aged+18-25+years%0A%0AResults%3A+MMN+amplitude+(comparison+of+standard+and+deviant+irrelevant+tones)+increased+with+focussed+attention+to+the+third+(target)+tone+and+frontal+maxima+shifted+slightly+posteriorly.+%0AThe+succeding+P3+in+the+difference+waveform+increased+more+posteriorly+than+frontally+confirming+continued+differential+processing+of+irrelevant+stimuli+under+active+conditions.++%0A%0AConclusion%3A+This+demonstrates+that+not+only+attending+to+stimuli%2C+but+the+active+processing+of+irrelevant+stimuli+(vs+passive+perception)+involves+small+changes+of+the+amount+and+distribution+of+neural+activity.+i.e.+active+controlled+processing+in+focussed+attention+can+affect+the+capacity+or+distribution+of+resources+even+for+automatic+processing+of+information+(the+MMN).%0A%0A&rft.publisher=Rapid+Communications+of+Oxford+Ltd&rft.date=1995&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F1182%2F2%2FNeuroreport.pdf&rft.identifier=++OADES%2C+Robert+D.+and+DITTMANN-BALCAR%2C+Alexandra++(1995)+Mismatch+negativity+(MMN)+is+altered+by+directing+attention.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F1182%2F