Action Dynamics Reveal Parallel Competition in Decision Making

When deciding between two alternatives, such as whether toorder the pasta or the chicken, or whether to pursue a career inacademia or industry, a person may feel torn—as if the optionsliterally pull him or her in two directions. This metaphor mayhavesomesurprisingliteraltruth.Ifasked,forexample,whether‘‘murder is sometimes justified,’’ individuals may be inclined toboth agree and disagree with the statement. Here, we document,for the first time, the pull toward contrasting responses duringevaluative thinking, reporting the results of a study examiningthe trajectory of participants’ reaching movements toward dif-ferent response options.Our results suggest that a decision process is not necessarilycompleted inthe brain’scognitivesubsystems before itissharedwith other subsystems, as has been traditionally assumed.Rather,simultaneous‘‘pull’’frommultipleresponsealternativesseemstoinfluencetheexecutionofmovementitself.Thisfindingsuggests that a dynamic approach to mental processing—anapproach that has already provided descriptions of perception,attention,andcategorization (e.g.,AbramsBGoldSGratton,Coles,Sirevaag,Eriksen,D Hovland & Sears, 1938; McClelland & Rogers, 2003;Spivey, 2007; Tipper, Howard, & Houghton, 1999)—may shednew light on high-level cognition (Roe, Busemeyer, & Town-send, 2001; Townsend & Busemeyer, 1989).