Hear rate variability during a 24-hour period recorded with a Polar heart rate monitor

Abstract

sound stimulation. We investigated 32 healthy subjects (15 men and 17 women with mean age of 22.1±1.3 years), and used a reference electrode on the thumbnail. The initial palmar SSR deflection was negative and the dorsal one was positive in 30 of the 32 subjects. In 16 of 30 subjects, the latencies of dorsal and palmar SSR deflections were similar. In 14 of 30 subjects, the latency of positive dorsal SSR deflection was longer than that of negative palmar SSR deflection (mean time delay was 269.6± 47.2 ms). As the reason for this difference of latencies, we hypothesized the presence of a true negative dorsal SSR deflection that was countered by a low amplitude positive SSR spread from the palmar to the dorsal side through the volume conductor. The true dorsal SSR waveform potential was recorded by computer simulation using both positive palmar SSR potential [kA (t)] with attenuation [k] and positive dorsal SSR potential [B (t)], suggesting that mental sweat glands also induced dorsal SSR. (The Autonomic Nervous System, 47: 386–392, 2010)