Research Report The orienting of visuospatial attention: An event-related brain potential study Durk Talsma a,b, * , Heleen A. Slagter c , Sander Nieuwenhuis d , Jasper Hage e , Albert Kok e a Center for Cognitive Neurosciences, Duke University, Durham, NC 27708, USA b Department of Clinical Neuropsychology, Vrije Universiteit, Amsterdam, The Netherlands c Psychonomics Department, University of Amsterdam, Amsterdam, The Netherlands d Department of Cognitive Psychology, Vrije Universiteit, Amsterdam, The Netherlands e Psychonomics Department, University of Amsterdam, Amsterdam, The Netherlands Accepted 27 April 2005 Available online 31 May 2005 Abstract This study investigated the electrophysiological correlates of shifting, maintaining, and relaxing the focus of attention, using a symbolic cuing task. Cues and imperative stimuli were presented in rapid succession, and the ADJAR procedure was used to remove the contribution of event-related potential (ERP) activity associated with the imperative stimulus from the cue-related ERP waveforms. Initial analyses, comparing left and right attention-directing cues, replicated previous findings of early directing attention negativity (EDAN) and anterior directing attention negativity (ADAN) effects. To isolate ERP activity that is common to leftward and rightward attention shifts, the combined ERP activity elicited by attention-directing cues was compared to the ERP activity elicited by non-informative cues. This analysis revealed a strong and broadly distributed early positivity followed by a sustained central negativity, possibly reflecting the controlled orienting and subsequent maintenance of attentional focus. Finally, imperative stimuli preceded by non-informative cues were characterized by an enhanced posterior P2 effect, with a scalp distribution indicative of generators in visual areas. This result suggests a relatively late (re)activation in visual areas associated with the processing of stimuli that had not been cued in advance. D 2005 Elsevier B.V. All rights reserved. Theme: Neural basis of cognition Topic: Cognition Keywords: Attention; Cuing; ERP; ADJAR; Spatial 1. Introduction To focus on task-relevant information and ignore what is irrelevant, the human mind is equipped with a mechanism that is known as selective attention. Current neurophysio- logical models of attention [12,25,26] make a distinction between control and expression mechanisms. Attentional control mechanisms can selectively influence sensory processing and are presumably located in anterior and posterior association areas, more specifically the dorsolateral prefrontal cortex and superior parietal cortex [3,13], as well as the anterior cingulate areas [33,39], which act in concert with subcortical structures [1,2,24,25]. Expression mecha- nisms, on the other hand, have been associated with sensory brain areas, such as the extrastriate visual areas [32,44], and produce attentional modulation of sensory processing. Single cell recordings in animals [29,35], electrophysiolog- ical scalp recordings in humans [18], as well as human neuroimaging studies [19] have provided evidence for the hypothesis that the activation level in perceptual areas can be modulated by attentional control systems. A common behavioral paradigm for studying shifts of visuospatial attention is the spatial cuing paradigm: on each 0926-6410/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.cogbrainres.2005.04.013 * Corresponding author. Department of Clinical Neuropsychology, Vrije Universiteit, Van den Boechorststraat 1, 1081 BT Amsterdam, The Netherlands. E-mail address: d.talsma@psy.vu.nl (D. Talsma). Cognitive Brain Research 25 (2005) 117 – 129 www.elsevier.com/locate/cogbrainres