This intriguing idea awaits experimental testing. As noted above, a key feature of signal detection theory is that the decision variable and the decision rule are distinct components of the decision process, with identifiably different consequences on behavior (Green and Swets, 1966 and Macmillan Alectinib supplier and Creelman, 2004). Given the dominant view of basal ganglia function in terms of action selection, it is natural to consider its role in implementing

the final rule, or selection process, of a winner-take-all decision between multiple alternatives (Berns and Sejnowski, 1995, Mink, 1996, Redgrave et al., 1999 and Wickens, 1993). A possible scheme that is consistent with the basal ganglia’s known roles in action selection is as follows. Different cortex-striatum ensembles form separate processing units that link inputs to actions. A specific input pattern leads to activation of the corresponding pallidal neurons, which subsequently disinhibit downstream thalamus/colliculus areas and enables the corresponding action. Activation of the same cortex-striatum ensemble also disinhibits subthalamic neurons via the GPe, which provides delayed and diffuse activation of pallidal projection neurons, such that all other actions are suppressed. In Selleck PD332991 principle, if the specific input pattern represents the prediction of a preferred outcome,

this scheme can support value-based decisions. Conversely, if the specific input pattern represents certain properties of sensory stimuli, this scheme can support perceptual decisions. If such a scheme is implemented in the basal ganglia, one might expect to observe correlates of a DDM-like bound crossing at the end of the decision process, representing a commitment to one of the two possible outcomes. As noted above, in monkeys performing an RT version of the dots task, this kind of activity is observed in LIP and FEF but not in the caudate (Figure 3). One interpretation of this difference between caudate Abiraterone manufacturer and LIP/FEF activity at the time of decision commitment is that the basal ganglia are only involved in

the early part of the decision process. Alternatively, bound crossing may occur downstream from the caudate in the basal ganglia pathway and then get sent back up to cortex. These ideas have not yet been tested directly. Despite the questions about if and how the basal ganglia might implement the decision rule, several lines of evidence suggest that they can at least help to adaptively modulate its implementation. For example, changing task demands can cause human subjects to adjust their speed-accuracy tradeoffs on an RT version of the dots task. These adjustments correspond to reliable changes in activation of the anterior striatum measured using fMRI (Forstmann et al., 2008 and Forstmann et al., 2010).