title: The Primary Visual Cortex Is Differentially Modulated by Stimulus-Driven and Top-Down Attention.
abstract: Selective attention can be focused either volitionally, by top-down signals derived from task demands, or automatically, by bottom-up signals from salient stimuli. Because the brain mechanisms that underlie these two attention processes are poorly understood, we recorded local field potentials (LFPs) from primary visual cortical areas of cats as they performed stimulus-driven and anticipatory discrimination tasks. Consistent with our previous observations, in both tasks, we found enhanced beta activity, which we have postulated may serve as an attention carrier. We characterized the functional organization of task-related beta activity by (i) cortical responses (EPs) evoked by electrical stimulation of the optic chiasm and (ii) intracortical LFP correlations. During the anticipatory task, peripheral stimulation that was preceded by high-amplitude beta oscillations evoked large-amplitude EPs compared with EPs that followed low-amplitude beta. In contrast, during the stimulus-driven task, cortical EPs preceded by high-amplitude beta oscillations were, on average, smaller than those preceded by low-amplitude beta. Analysis of the correlations between the different recording sites revealed that beta activation maps were heterogeneous during the bottom-up task and homogeneous for the top-down task. We conclude that bottom-up attention activates cortical visual areas in a mosaic-like pattern, whereas top-down attentional modulation results in spatially homogeneous excitation.
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Bekisz
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bogdan
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Anaida
authors.initials: A
authors.lastname: Ghazaryan
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Wioletta J
authors.initials: WJ
authors.lastname: Waleszczyk
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Kublik
authors.affiliation: Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Wróbel
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D059031:Anticipation, Psychological / Q000502:physiology; D001288:Attention / Q000502:physiology*; D002415:Cats; D003463:Cues; D004193:Discrimination Learning / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D004558:Electric Stimulation; D005074:Evoked Potentials, Visual / Q000502:physiology*; D008297:Male; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*