(A) The average HRV measured as the coefficient of variation (CV) of the inter-beat-interval is displayed across the experimental blocks: initial resting state recording (Pre), initial exploration (Explor), first block of learning (Learn1) and, last block of learning (Learn2). Relative to Pre, there was a significant drop in HRV in anx1 participants during initial exploration (within-subject statistics with paired permutation tests, after controlling the false discovery rate [FDR] at level q = 0.05 due to multiple comparisons, termed ). In anx2 participants, the drop in HRV was found during the first learning block, which was targeted by the anxiety manipulation (). Between-group comparisons revealed that anx1, relative to the control group, exhibited a significantly lower HRV during the exploration phase (, purple bar at the bottom). The anx2 group manifested a significant drop in HRV relative to controls during the first learning block (, red bar at the bottom). These results demonstrate a group-specific modulation of anxiety relative to controls during the targeted blocks. The mean HR did not change within or between groups (). (B) STAI state anxiety score in each group across the different experimental phases. Participants completed the STAI state anxiety subscale first at the start of the experiment before the resting state recording (Pre) and subsequently again immediately before each experimental block (and right after the anxiety induction: Explor, Learn1, Learn2). There was a within-group significant increase in the score for each experimental group during the phase targeted by the anxiety manipulation (anx1: Explor relative to Pre, average score 40  and 31 , respectively; ; anx2: Learn1 relative to Pre, average score 39  and 34 , respectively; ). Between-group differences were non-significant.