Fig. 4: Reduced relation between dlPFC and midbrain temporal difference signals during neurofeedback training correlates with midbrain DRT.

a The relation between dlPFC activity and the SN/VTA signal encoding the temporal difference between the current and immediately preceding feedback activity decreased with ongoing feedback training (i.e., the slope over the first and second neurofeedback training run) more strongly in individuals with higher midbain DRT (p < 0.001 uncorrected). It is important to note that this figure depicts the negative correlation of temporal difference coding with DRT on the group level. The finding is consistent with reinforcement learning theories, according to which temporal differences decrease as learning progresses. By extension, a reinforcement learning framework can explain successful neurofeedback training. b Scatter plot illustrating that the slope of temporal difference signals in dlPFC over the NF training runs is statistically related to the individual degree of transfer success. The plot is for illustration purposes only without further significance testing to avoid double dipping. The grey shaded area identifies the 95% confidence interval (n = 42 subjects). See Supplementary Table 5 for full result overview.