Multi-site phasic neural activity mediates the execution of an auditory continuous performance task: a PET and electrophysiological study.
OBJECTIVE
We studied an auditory continuous performance task with positron emission tomography(PET) and EEG-derived current density reconstructions (CDRs) to define the spatial and temporal aspects of auditory attention.


METHODS
The CDRs were employed to segregate responses to targets and non-targets at sites identified by PET. We then studied the time course of brain activity using statistical parametric mapping (SPM) of the CDR data.


RESULTS
In contrast to target EEG activity, non-targets did not produce significant peaks after 300 ms. Pre-300 ms biphasic activation of auditory, left posterior frontal, left supplemental,and primary motor cortices and the anterior cingulate (AC) and biphasic suppression of posterior cingulate and occipital cortex were identical for targets and non-targets and may mediate the target non-target decision. SPM analysis of post-300 ms CDRs showed cingulate cortices were the first to be reactivated, remained active through 672 ms, and were accompanied by reactivation and deactivation of the same sites observed in the pre-P300 responses.


CONCLUSIONS
The cingulate may play an important role in post-decisional activity and control activity at other sites involved in post-decisional cognitive processing.
Lockwood
Alan H
AH
Center for PET, VA Western NY Healthcare System, University at Buffalo, Buffalo, NY 14215, USA. ahl@buffalo.edu
Wack
David S
DS
Benedict
Ralph H B
RH
Coad
Mary Lou
ML
Sussman
Joan E
JE
Burkard
Robert F
RF
D000293:Adolescent; D000328:Adult; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003657:Decision Making / Q000502:physiology; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography / Q000379:methods*; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009483:Neuropsychological Tests; D010700:Phonetics; D049268:Positron-Emission Tomography / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D013067:Speech Perception / Q000502:physiology*; D055815:Young Adult