title: Isolating event-related potential components associated with voluntary control of visuo-spatial attention.
abstract: Attention-directing cues presented at fixation evoke several lateralized event-related potential (ERP) components prior to the onset of visual targets. These components have been associated with the control of visuo-spatial attention, but the neuro-cognitive operations and neural generators of the components are still largely unknown. Here, we isolated cue-elicited ERP activity in different ways to home in on different neuro-cognitive operations and to gain a better understanding about the possible neuroanatomical sources of the cue-elicited ERP activities. To isolate lateralized cue-ERP activity, we compared shift-left and shift-right cue ERPs to shift-up cue ERPs. To measure all of the ERP activity related to attentional control, including spatially nonspecific activity that is removed in the process of isolating lateralized cue-ERP components, we compared shift-cue ERPs to neutral-cue (i.e., no-shift) ERPs. Isolated lateralized-ERP activity was seen in the contralateral-occipital lobe in the early phase of the cue-target interval and in the ipsilateral-occipital lobe in the late phase. The later, ipsilateral activity indicates that the late directing attention positivity (LDAP) reflected processing of the to-be-ignored location. The neutral-cue isolation revealed a shift-related positivity over posterior scalp regions and a shift-related negativity over more anterior scalp regions. The spatio-temporal sequence of shift-related activity observed on the scalp, together with estimates of distributed source activity underlying the shift-related ERP components, indicated that frontal and parietal regions of cortex participated in the control of attention and led to pre-target biasing in visual cortical areas.
authors.affiliation: Simon Fraser University, Department of Psychology, Burnaby, Canada. jmcd@sfu.ca
authors.forename: John J
authors.initials: JJ
authors.lastname: McDonald
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Green
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D003463:Cues; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D009778:Occipital Lobe / Q000502:physiology; D009949:Orientation / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*