This simultaneous

encoding of alternative competing motor goals is also fundamentally different from the representation of two sequential movement goals. Previous experiments showed that in the parietal cortex, during the planning of a multicomponent (double-step) movement, two neural populations GSK 3 inhibitor were activated, each of which was selective for one of the single movement components (Medendorp et al., 2006 and Baldauf et al., 2008). Double-step experiments do not induce a decision process between mutually exclusive action goals, and rather suggest that multiple components of a complex movement can be planned at once. Our finding of simultaneous encoding of alternative competing motor goals does complement previous observations in effector-selection experiments, which showed that alternative eye or hand movements to the same spatial target, instructed (Calton et al., 2002) or freely chosen (Cui and Andersen, 2007), can elicit simultaneous movement planning activity in LIP and PRR. The advantage of the goal-selection scheme over the rule-selection scheme for decision

making could be that—by computing all associated motor goal alternatives and their implicit action plans during the ambiguous state of planning—a more comprehensive cost-benefit calculation of each choice can be achieved. When the striker in our introductory example has to decide between aiming for the position of the goal keeper versus the opposite corner, then it is not enough to consider the likelihood of the Panobinostat in vitro keeper to jump or stay. Also the costs associated with the striker’s action alternatives are relevant, e.g., the striker might be poor at aiming for right-side goals, or the ball might be in an immediate position that eases aiming for one corner but not the other. Our results imply that the decision process in our rule-selection experiment selected between competing motor-goal alternatives, not between

different transformation rules or target stimuli, and that this competition likely happened in the sensorimotor areas that are involved in planning the respective movements. Note, we do note rule out the possibility that in Levetiracetam parallel a competition between the two potential rules takes place in rule-encoding frontal cortical areas (White and Wise, 1999, Wallis et al., 2001, Wallis and Miller, 2003 and Genovesio et al., 2005). The rule-competition could then, in the extreme case, just be mirrored by probabilistic motor goal representations in downstream sensorimotor areas. Because of the observed response normalization in our data (see below), we believe that if at all there was a rule-competition in our task then it was paralleled by a goal-competition in the sensorimotor areas, which would make sense for economical reasons, as discussed in the previous paragraph (Cisek and Kalaska, 2010).