The mediating role of heart rate variability in people with trait anxiety in a change blindness task.

Introduction: Heart rate variability (HRV) represents a measure of the functioning of the cardiac autonomic nervous system that has been correlated to several emotional, cognitive and cardiovascular dysfunctions. Previous studies have shown that reduced vagal tone is associated with trait anxiety and HRV may be considered as a promising physiological correlate of attentional control. Aims: Since high levels of anxiety may be detected in subjects with a generale deficit in attentional control, this study is aimed to evaluate the relationship between HRV, anxiety and attentional control. Methods: Forty-nine university students (26F/23M) participated in the study. Using the State-Trait Anxiety Inventory they were divided into two groups of High Trait Anxiety (N=25; HTA) and Low Trait Anxiety (N=24; LTA). Participants completed the Emotional Flicker Task. Results: The ANOVAs on HRV indices did not show any difference between the groups (F< 1). The mixed ANOVA on Response Times (RTs) to the FT showed a significant interaction Group x Change Type (F2,92= 5.18; p= 0.03; ƞp2= 0.10). In MA change, HAT showed faster RT than LTA; however, no effect of the valence of the stimuli was significant. In the HAT group, a significant negative correlation between the HF-HRV index and RTs in CE change pictures (p= 0.01) when the stimuli were NEG. In the LTA group, no significant correlation was found. Discussion: This study showed in people with high levels of anxiety higher difficulty in the detection of the changes when the involvement of voluntary attention was necessary (MA changes). Although any differences between-groups in HRV indices were found, negative correlations between HR-HRV measures and RTs were observed. Moreover, for the high anxiety participants higher levels of the HF-HRV index were significantly associated with RTs, for the CE changes of the NEG valence images. These findings suggest that an increase in the vagal tone facilitates the elaboration of threatening stimuli in anxious individuals. More studies are needed to provide further support the hypothesis of the HRV as a marker of attentional performances in high anxiety individuals.