Table 4

Summaries of group differences in DDM model parameters and of tolcapone effects on DDM model parameters

DDM model parameterGroup differenceTolcapone effect
MdiffdBFMdiffdBF
Boundary separation (α)0.9661.15328.00.0630.0891.81
Non decision time (τ)0.3280.78414.87–0.003–0.0310.815
Starting point / bias (z)–0.011–0.2110.4030.0040.0881.47
Drift rate v (max)–0.236–0.7410.065–0.166–1.840.073
Drift rate v (coeff)–0.047–0.8650.1810.0690.9107.51
Log(h)0.5750.3444.40–0.286–0.2810.20
  • In the summary of group differences in DDM model parameters, for each parameter, we report the mean group difference (controls – gamblersplacebo), standardized effect sizes (Cohen’s d; see Materials and Methods), and BF testing for directional effects (Marsman and Wagenmakers, 2017; Pedersen et al., 2017). BF < 0.33 indicate evidence for an increase in gamblersplacebo versus controls, whereas BF > 3 indicates evidence for a reduction (see Materials and Methods). In the summary of tolcapone effects on DDM model parameters, for each parameter, we report the mean change under tolcapone versus placebo, standardized effect sizes (Cohen’s d), and BF testing for directional effects. Here, BF > 3 indicates evidence for an increase under tolcapone, whereas BF < 0.33 indicates evidence for a decrease.