Brain Structures Involved in Visual Search in the Presence and Absence of Color Singletons

■ It is still debated to what degree top–down and bottom–up driven attentional control processes are subserved by shared or by separate mechanisms. Interactions between these attentional control forms were investigated using a rapid event-related fMRI design, using an attentional search task. Following a prestimulus mask, target stimuli (consisting of a letter C or a mirror image of the C, enclosed in a diamond outline) were presented either at one unique location among three nontarget items (consisting of a random letter, enclosed in a circle outline; 50% probability), or at all four possible target locations (also 50% probability). On half the trials, irrelevant color singletons were presented, consisting of a color change of one of the four prestimulus masks, just prior to target appearance. Participants were required to search for a target letter inside the diamond and report its orientation. Results indicate that, in addition to a common network of parietal areas, medial fr...

• Type: Journal
• Year: 2010
• Where: JOCN
• Authors: Durk Talsma, Brian Coe, Douglas P. Munoz, Jan Theeuwes
• Keywords: Attentional Control, Irrelevant Color Singleton, JOCN 2010, Parietal Areas