Premium
Underlying mechanisms of the P3a task‐difficulty effect
Author(s) -
Kimura Motohiro,
Katayama Jun'ichi,
Murohashi Harumitsu
Publication year - 2008
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.2008.00684.x
Subject(s) - p3a , psychology , mismatch negativity , oddball paradigm , negativity effect , stimulus (psychology) , cognitive psychology , event related potential , task (project management) , audiology , electroencephalography , distraction , orienting response , developmental psychology , neuroscience , habituation , medicine , management , economics
In three‐stimulus oddball studies, even typical deviant stimuli elicited a large P3a event‐related brain potential (ERP) when target/standard discrimination was difficult. To investigate the underlying mechanisms, the effects of task difficulty on early deviant‐related ERPs were assessed. Four visual stimuli defined by an orthogonal combination of task‐relevant size (nontarget 80%, target 20%) and task‐irrelevant luminance (standard 80%, deviant 20%) were presented randomly, where two task difficulties (easy, difficult) were defined by target/nontarget discriminability. An increase in task difficulty enhanced P3a as well as a posterior negativity (change‐related negativity) and an anterior positivity (frontal positivity) elicited by deviant nontarget stimuli. These results suggest that attentional modulation of refractoriness‐based rareness detection and an attention‐triggering process underlie the P3a task‐difficulty effect.