Evidence of Change of Intention in Picking Situations Ariel Furstenberg, Assaf Breska, Haim Sompolinsky, and Leon Y. Deouell Abstract ■ Intending to perform an action and then immediately exe- cuting it is a mundane process. The cognitive and neural mech- anisms involved in this process of “proximal” intention formation and execution, in the face of multiple options to choose from, are not clear, however. Especially, it is not clear how intentions are formed when the choice makes no difference. Here we used behavioral and electrophysiological measures to investi- gate the temporal dynamics of proximal intention formation and “change of intention” in a free picking scenario, in which the alternatives are on a par for the participant. Participants pressed a right or left button following either an instructive vis- ible arrow cue or a visible neutral “free-choice” cue, both pre- ceded by a masked arrow prime. The goal of the prime was to induce a bias toward pressing the left or right button. Presum- ably, when the choice is arbitrary, such bias should determine the decision. EEG lateralized readiness potentials and EMG measurements revealed that the prime indeed induced an in- tention to move in one direction. However, we discovered a signature of “change of intention” in both the Instructed and Free-choice decisions. These results suggest that, even in arbi- trary choices, biases present in the neural system for choosing one or another option may be overruled and point to a curious “picking deliberation” phenomenon. We discuss a possible neu- ral scenario that could explain this phenomenon. ■ INTRODUCTION In many daily life situations, we intend to perform an ac- tion selected from several alternatives and immediately execute it. The cognitive and neural mechanisms in- volved in this process of intention formation and execu- tion are not clear, however. For example, intentions can be directed exogenously by an instructive cue (e.g., the green traffic light signal) or formed endogenously accord- ing to “free” will (e.g., “I am going to wear my blue jacket today”; for a recent overview, see Janczyk, Nolden, & Jolicoeur, 2014). Experimentally, the latter is typically in- vestigated in Libet-style experiments in which an endoge- nously driven decision includes selecting between options that are on a par for the participant (Libet, 1985), for in- stance, pressing a right or left button according to what the participant “freely wants” when a cue appears. This type of selection between options that make no difference to the agent is termed “picking” (following Ullmann- Margalit & Morgenbesser, 1977) and is distinguished from “choosing,” in which the selection is based on reasoning. We focus here on immediate (“proximal”) picking selec- tions (i.e., the intention to do something now, in contrast to long-term commitments and intentions; Furstenberg, 2014; Mele, 2009) and investigate the dynamics that underlies the selection process in these picking scenarios. The most basic question about true picking situations is why picking situations do not result in paralysis or how, lacking any difference between the choices or any other reason, a decision is made at all. This was nicely described by Spinoza: “if a man were placed in such a state of equi- librium he would perish of hunger and thirst, supposing he perceived nothing but hunger and thirst, and the food and drink were equidistant from him” (Spinoza, 1677/1930). 1 A natural solution is that although on one, explicit or reason- based level, there is symmetry between the alternatives (i.e., there is no reason to prefer one option over the other), on a lower, implicit level the symmetry does not main- tain. The underlying asymmetry between alternatives is what makes possible the picking of one alternative rather than the other; if the symmetry were maintained through- out all levels, picking would be impossible. In the words of Leibniz: “insensible impressions…can suffice to tilt the bal- ance…we are never indifferent, even when we appear to be most so, as for instance over whether to turn left or right at the end of a lane. For the choice that we make arises from these insensible stimuli.” (Leibniz, 1765/1981; see Furstenberg, Deouell, & Sompolinsky, 2015, for further dis- cussion of this philosophical question). Here, we studied the notion of this implicit asymmetry and its influence on the final decision by measuring brain signals related to motor preparation. These signals, on the verge of overt action, provide evidence that an intention has been formed (Furstenberg, 2014). For this purpose, we used a simple picking scenario, in which an agent freely selects whether to press a button using the left or right hand with no specific advantage to either decision over the other. We presented an external subliminal prime in attempt to create an implicit asymmetry between the two alternatives. Studies show that, in cases The Hebrew University of Jerusalem © 2015 Massachusetts Institute of Technology Journal of Cognitive Neuroscience 27:11, pp. 2133–2146 doi:10.1162/jocn_a_00842