, 2012) or deadline (Heitz and Schall, 2012). One might imagine decision bounds that squeeze inward as a function of time, thereby lowering the criterion for termination.

However, the brain achieves this by adding a time-dependent (evidence-independent) signal to the accumulated evidence, which MAPK inhibitor we refer to as an “urgency” signal (Churchland et al., 2008 and Cisek et al., 2009). The urgency signal adds to the accumulated evidence in all races, bringing DVs closer to the bound rather than bringing the bounds closer to the DVs. The bound itself is a fixed firing rate threshold (as in Figure 3D, see also Hanes and Schall, 1996). This suggests that the termination mechanism could be achieved with a simple threshold crossing, unencumbered by details such as the cost of time, the tradeoff between speed and accuracy, and other

policies that affect the decision criteria. By implementing these policies in areas like LIP, the brain can use the same mechanism to sense a threshold crossing yet exercise different decision criteria for different processes. For example, it may take less accumulated evidence to decide to look at something than to grasp or eat it. We are suggesting SCH 900776 mouse that different brain modules, supporting different provisional intentions, can operate on the same information in parallel and apply different criteria (Shadlen et al., 2008). This insight effectively reconciles SDT with high-threshold theory: the bound is the high threshold, but it (via the starting point) is also an adjustable criterion, which may be deployed differently depending on policies and desiderata. As explained later, this parallel intentional architecture lends insight into

seemingly mysterious distinctions, such as preparation without awareness of volition (Haggard, 2008), subliminal cuing, and nonconscious cognitive processing (Dehaene et al., 2006 and Del Cul et al., 2009). Put simply, too little evidence to pierce consciousness might be enough information to prepare another behavior. The key is to recognize consciousness as just another kind of decision to engage in a certain way (Shadlen and Kiani, 2011). To be clear, Cytidine deaminase we suspect that LIP is one of many areas that represent a DV, and it does so only because the decision before the monkey is not “Which direction?” but “Which eye movement target?” Other areas are involved if the decision is about reaching to a target (e.g., Pesaran et al., 2008 and Scherberger and Andersen, 2007) and still others, presumably, if the decision is about whether an item is a match or nonmatch, for example (Tosoni et al., 2008; but see Heekeren et al., 2006). This, however, will remain a matter of speculation until a neural correlate of a DV is demonstrated in these situations. We place emphasis on the DV because it is a level of representation that can be dissociated from sensory processing of evidence and motor planning. The DV is not the decision.