Fig. 4

The task difficulty parameter (TDP) for the time limit and successful experience during training sessions. The individual TDP values across training sessions were plotted for both the control group (A) and the autonomy support group (B). The averaged TDP, total use, and successful experience during the early and late phases of training were presented (C–E). The failed experience (F), the success rate (G) and the perseverance (H) during the early and late phases were shown. It was observed that the TDP was lower in the autonomy support group compared to the control group. Additionally, the autonomy support group had significantly higher levels of successful experience compared to the control group. NS non-significant, **p < 0.01, ***p < 0.001