Beyond reach: Do symmetric changes in motor costs affect decision making? A registered report

Abstract

<p>Executing an important decision can be as easy as moving a mouse cursor or reaching towards the preferred option with a hand. But would we decide differently if choosing required walking a few steps towards an option? More generally, is our preference invariant to the means and motor costs of reporting it? Previous research demonstrated that asymmetric motor costs can nudge the decision-maker towards a less costly option. However, virtually all traditional decision-making theories predict that increasing motor costs symmetrically for all options should not affect choice in any way. This prediction is disputed by the theory of embodied cognition, which suggests that motor behavior is an integral part of cognitive processes, and that motor costs can affect our choices. In this registered report, we investigated whether varying motor costs can affect response dynamics and the final choices in an intertemporal choice task: choosing between a readily available small reward and a larger but delayed reward. Our study compared choices reported by moving a computer mouse cursor towards the preferred option with the choices executed via a more motor costly walking procedure. First, we investigated whether relative values of the intertemporal choice options affect walking trajectories in the same way as they affect mouse cursor dynamics. Second, we tested a hypothesis that, in the walking condition, increased motor costs of a preference reversal would decrease the number of changes-of-mind and therefore increase the proportion of impulsive, smaller-but-sooner choices. We confirmed the hypothesis that walking trajectories reflect covert dynamics of decision making, and rejected the hypothesis that increased motor costs of responding affect decisions in an intertemporal choice task. Overall, this study contributes to the empirical basis enabling the decision-making theories to address the complex interplay between cognitive and motor processes.</p>

A Hierarchical Attractor Network Model of perceptual versus intentional decision updates

“…Thus, action selection does not rely on full anticipation of motor costs 4 , but instead, costs may be updated continuously as actions evolve 52 – 54 . Interestingly, in contrast to previous studies 4 , 8 , 37 , we did not observe an overall increase in perceptual CoM in close compared to far targets. Hence, in our study, motor costs did not affect whether or not participants changed an ongoing action.…”

“…By contrast, here we extend previous work by introducing a multimodal, hierarchically organised Attractor Network Model that continuously integrates multiple factors relevant to decision-making, namely: (1) higher-order, internal intentions, (2) external perceptual evidence, and (3) motor costs. Although some previous studies have considered how costs or rewards affect perceptual decisions, these studies treated reward/cost information as a static decision variable that simply biases choices or shifts decision thresholds across trials 8 , 36 , 37 . By contrast, in our model, each source of information provides independent information and needs to be integrated continuously and dynamically during the evolving decision process.…”

Should I stay or should I go? Evidence accumulation drives decision making in human drivers

“…In our study, duration of a decision process provided a useful but coarse-grained measurement of a cognitive process. Going beyond response times, dynamic measures such as movement trajectories can provide researchers with rich data about a cognitive process [39], [40]. This includes, for instance, information on gradual or abrupt reversal of preference prior to commitment to the final decision (changes-of-mind).…”

The action dynamics of approach-avoidance conflict during decision-making

“…DST models of decision-making consider the actions available to an organism to be attractors in a psychological or decision state space, and a decision is made when the current state in this decision space is at one of these attractors. The movement of the mouse cursor during a response trajectory reflects, to some degree, movement in this decision space (O'Hora et al, 2013;Zgonnikov et al, 2017Zgonnikov et al, , 2019. In approach-avoidance decisions, the decision space is updated continuously as the system evaluates the options.…”