The guidance of visual attention in humans and non-human primates is thought to be controlled by a frontoparietal network of brain areas including the dorsolateral prefrontal (dlPFC) and posterior parietal (PPC) cortex (Corbetta & Shulman, 2002; Schall, RGFP966 supplier 2002; Bisley & Goldberg, 2010). PPC and dlPFC neurons share many properties, including

large receptive fields and greatly enhanced responses to attended than to unattended stimuli (Schall & Hanes, 1993; Constantinidis & Steinmetz, 2001; Katsuki & Constantinidis, 2012b). Traditionally, PPC has been thought to be relatively more important in the processing of bottom-up information for the determination of visual saliency and PFC has been thought of as the source of top-down information (Buschman & Miller, 2007; Ibos et al., 2013). This dichotomy has been challenged by some studies suggesting similar courses of activation in posterior parietal PI3K Inhibitor Library research buy areas, such as the lateral intraparietal area (LIP) and area 7a, and prefrontal areas, such as area 46 and the frontal eye field (FEF) of dlPFC, in behavioral tasks requiring bottom-up attention (Thompson et al., 1996; Thomas & Pare, 2007; Katsuki

& Constantinidis, 2012a; Purcell et al., 2013). A recent study revealed that dlPFC represents a stimulus that attracts attention by bottom-up factors alone no later than PPC even though the initial visual response latency of neurons was shorter in PPC than dlPFC (Katsuki & Constantinidis, 2012a). These results suggest an early involvement of dlPFC in

the representation of bottom-up saliency, raising the possibility that behavioral choices are shaped jointly by the activity in the two areas. Evidence in support of this view suggests that activity of both PFC and PPC neurons can bias behavioral choice and performance in a motion discrimination task and visual search tasks (Thompson et al., Tryptophan synthase 2005; Hanks et al., 2006; Heitz et al., 2010). However, parallel time courses of stimulus representation do not necessarily imply identical roles for the two areas in the guidance of visual attention. Distinct neurophysiological patterns of responses between dlPFC and PPC have been described with respect to the representation of distracting stimuli, with dlPFC being better able to filter distractors (Qi et al., 2010; Suzuki & Gottlieb, 2013). Different behavioral effects have also been demonstrated after reversible inactivation of each area, where inactivation of PFC affected both easy and difficult search performance while inactivation of PPC affected only difficult search performance (Wardak et al., 2004, 2006). Activity in the two areas may still be specialized on different respects of guidance of attention. We therefore tested whether behavior correlated with neuronal activity, equally for PPC and dlPFC.