Figure 1.

Illustration of a sequential sampling model of effort-based decision making. Within a trial, evidence about the relative value of each choice option (exert effort vs. skip trial) is accumulated over time with mean rate v until a threshold is reached, which triggers the corresponding response (at the time labeled response onset). Response time is the time it takes to reach a threshold (decision time) plus an intercept term representing non-decision processes (e.g., perceptual encoding and motor response time). Note that other linking functions between drift rate and choice utility are possible. For an introduction to applying such models to experimental data, Voss et al. (2013).