This is particularly clear for the Simon task. In this task, participants are asked to respond with a left or right hand response to a certain stimulus feature, typically the color of a circle [11]. The stimuli are presented left or right of a central fixation cross. This

spatial outline creates a condition in which the location of the stimulus (e.g. left of the fixation cross) is congruent with the required response (e.g. the color blue should yield a left button press), and a condition in which the location of the stimulus and the required response are incongruent (e.g. a blue circle to the right of the fixation cross, requiring a left button press). The Simon task is demanding because on incongruent trials, participants are confronted with interfering information in the form of the spatial location, but have to respond to the task-relevant feature only. The response time distributions of the Simon task deviate from other Sotrastaurin cost conflict tasks in that the time cost of resolving the interfering information is mostly associated with relatively fast PI3K Inhibitor Library in vivo responses. That is, most conflict tasks show a greater interference effect for slower responses, but the Simon task shows the greater interference effect for faster responses

[13]. This pattern of interference is atypical for most conflict tasks. It suggests that in terms of the cause of interference, more processes are involved than in for example a flanker task [14]. While it is clear that an accumulator model of spatial interference control such as in the Simon task would greatly increase our understanding of cognitive control, as yet no such ifoxetine model has been published. The aim of the current article is to pave the way to use accumulator models to understand latent processes in spatial interference control. That is, based on previous model-based approaches towards the neural basis of perceptual decision

making, and previous functional Magnetic Resonance Imaging (fMRI) studies in spatial interference control, we aim to outline the important processes in an accumulator model of spatial interference. In this section we review basic perceptual decision making experiments that have sought to relate diffusion model properties to Blood Oxygen Level Dependence (BOLD) responses. In fact, the two most important properties of the diffusion model can be identified in the brain [3••]. The rate of evidence accumulation has been shown to be positively related to BOLD in dorsolateral prefrontal cortex (DLPFC, e.g. 15, 16 and 17) and anterior Insula (aI, e.g. 15, 16, 17 and 18). Thus, a high accumulation rate elicits a stronger BOLD response than a low accumulation rate, suggesting that easier perceptual decisions yield a stronger BOLD response in DLPFC than hard perceptual decisions. In addition, some studies report a correlation between the rate of evidence accumulation and the BOLD signal in right inferior frontal gyrus (rIFG, 19 and 20•).