02535nas a2200277   4500008004100000022001400041245009300055210006900148260001200217300000700229490000600236520172900242653002101971653002501992653001402017653001902031653002902050100002002079700001902099700001602118700001902134700001802153700001902171700001902190856004802209       2011                        eng d  a1662-516100aNeural Correlates of Covert Attention in Electrocorticographic (ECoG) Signals in Humans.0 aNeural Correlates of Covert Attention in Electrocorticographic E  c09/2011  a890 v53 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Attention is a cognitive selection mechanism that allocates the limited processing resources of the brain to the sensory streams most relevant to our immediate goals, thereby enhancing responsiveness and behavioral performance. The underlying neural mechanisms of orienting attention are distributed across a widespread cortical network. While aspects of this network have been extensively studied, details about the electrophysiological dynamics of this network are scarce. In this study, we investigated attentional networks using electrocorticographic (ECoG) recordings from the surface of the brain, which combine broad spatial coverage with high temporal resolution, in five human subjects. ECoG was recorded when subjects covertly attended to a spatial location and responded to contrast changes in the presence of distractors in a modified Posner cueing task. ECoG amplitudes in the alpha, beta, and gamma bands identified neural changes associated with covert attention and motor preparation/execution in the different stages of the task. The results show that attentional engagement was primarily associated with ECoG activity in the visual, prefrontal, premotor, and parietal cortices. Motor preparation/execution was associated with ECoG activity in premotor/sensorimotor cortices. In summary, our results illustrate rich and distributed cortical dynamics that are associated with orienting attention and the subsequent motor preparation and execution. These findings are largely consistent with and expand on primate studies using intracortical recordings and human functional neuroimaging studies.</span></p>10acovert attention10aElectrocorticography10aintention10amotor response10avisual-spatial attention1 aGunduz, Aysegul1 aBrunner, Peter1 aDaitch, Amy1 aLeuthardt, E C1 aRitaccio, A L1 aPesaran, Bijan1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/22046153