Abstract
                 Background: Initiated by biological plausibility and supported by the pilot study, we observed possibility of associations  between cardiovascular autonomic milieu and academic performances. As there are established cognitive ability differences  among gender in literature, we designed a study to observe the differences in the basal autonomic activity as well as the manner  of association between autonomic activity and academic performance between genders. Considerable lacunae in literature  on this aspect also warranted for scientific introspection on this lacuna. Aims and Objective: The aim of this study is to  observe the association between resting short-term heart rate variability (HRV) indices and University marks of anatomy,  biochemistry, and physiology in young male and female medical students. Materials and Methods: Cross-sectional  observational study with 102 healthy young participants in which 34 boys and 68 girls between 18 and 22 years were  included by convenient sampling after assessing the inclusion and exclusion criteria. HRV is computed under standard  conditions as per the task force recommendations in time and frequency domains. The academic performance is assessed  st by University examination marks at the end of the 1 year. The comparison of HRV parameters, academic performance,  and their associations was analyzed separately by gender. Type 1 error allowance fixed at 5% but considering the high  dispersion of HRV data, P values between 0.1 and 0.05 were also discussed. Results: Mean RR intervals showed a  negative correlation with academic performance in males. Time domain and geometric indices of HRV showed a negative  correlation in boys but not in girls. In case of frequency domain indices, all indices of sympathetic activity showed a  positive correlation with academic performance in boys and not in girls. Furthermore, sympathetic indices are more in males  compared to females. All indices of parasympathetic reactivity were negatively correlated with academic performance in  males. Conclusion: High-sympathetic activity is correlated with better cognitive ability in males but the same association  is not seen in females.