Neural precursors of decisions that matter—an ERP study of deliberate and arbitrary choice

Abstract

The readiness potential (RP)—a key ERP correlate of upcoming action—is known to precede subjects' reports of their decision to move. Some view this as evidence against a causal role for consciousness in human decision-making and thus against free-will. But previous work focused on arbitrary decisions—purposeless, unreasoned, and without consequences. It remains unknown to what degree the RP generalizes to deliberate, more ecological decisions. We directly compared deliberate and arbitrary decision-making during a $1000-donation task to non-profit organizations. While we found the expected RPs for arbitrary decisions, they were strikingly absent for deliberate ones. Our results and drift-diffusion model are congruent with the RP representing accumulation of noisy, random fluctuations that drive arbitrary—but not deliberate—decisions. They further point to different neural mechanisms underlying deliberate and arbitrary decisions, challenging the generalizability of studies that argue for no causal role for consciousness in decision-making to real-life decisions.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).

Dissociating cognitive and motoric precursors of human self-initiated action

“…Interestingly, a recent study compared neural precursors of action for arbitrary and deliberate decisions (Maoz et al 2018). While RPs were found for arbitrary decisions, they were absent in deliberate decisions.…”

Integrated World Modeling Theory (IWMT) Revisited

“…If these models regarding the neural substrates of consciousness are accurate, then they may also help contextualize findings where agency appears to be missing, as famously described by the Libet (1983) experiment in which the subjective experience of motor commands were observed to come after highly predictive neural activity. Potential limitations of the paradigm notwithstanding (Dennett, 2003;Fifel, 2018;Maoz et al, 2019), the question arises as to how mental states could be causal, given that we expect causes to precede effects. Theoretically, people's reports regarding the feeling to act occurring after preparatory motor activity could be partially accounted for by effective connectivity with a largely unconscious inner core.…”

Why neuroscience does not disprove free will

“…If participants have a strong motivation to act in a specific way and little or no opposing motivation, does it even make sense to say that they choose to act that way? An alternative is to give the options some value, while avoiding making the value of one obviously greater than the value of the other(s) (for such a method see Maoz et al, 2018). The resulting situation may be more similar to real-life situations in which we make choices than is the situation in which participants in Libet-style experiments find themselves.…”