 The 2nd objective will be assessed by measuring the concentration of miRNAs in recruited healthy volunteers before and after a brief public speech. The circulating miRNAs will be detected directly from 1 - 5 ul of plasma samples with the miRFLP assay. This capillary electrophoresis-based miRNA quantification method detects multiple miRNAs in absolute copy number in smaller sample signature with negligible batch to batch variation, thus providing a standardizable miRNA detection method. 