Risk Anal. 2011 Aug;31(8):1187-95. doi: 10.1111/j.1539-6924.2011.01589.x. Epub 2011 Mar 18.
This study investigated risk compensation by cyclists in response to bicycle helmet wearing by observing changes in cycling behavior, reported experience of risk, and a possible objective measure of experienced risk. The suitability of heart rate variability (HRV) as an objective measure of experienced risk was assessed beforehand by recording HRV measures in nine participants watching a thriller film. We observed a significant decrease in HRV in line with expected increases in psychological challenge presented by the film. HRV was then used along with cycling pace and self-reported risk in a field experiment in which 35 cyclist volunteers cycled 0.4 km downhill, once with and once without a helmet. Routine helmet users reported higher experienced risk and cycled slower when they did not wear their helmet in the experiment than when they did wear their helmet, although there was no corresponding change in HRV. For cyclists not accustomed to helmets, there were no changes in speed, perceived risk, or any other measures when cycling with versus without a helmet. The findings are consistent with the notion that those who use helmets routinely perceive reduced risk when wearing a helmet, and compensate by cycling faster. They thus give some support to those urging caution in the use of helmet laws.
本研究通过观察骑行行为、报告的风险体验以及可能的客观风险体验衡量指标的变化，调查了自行车手在佩戴头盔后的风险补偿行为。研究人员事先通过记录 9 名参与者观看惊悚片时的心率变异性（HRV）测量值，评估了 HRV 作为客观风险体验衡量指标的适用性。在一项现场实验中，研究人员使用 HRV 与骑行速度和自我报告的风险相结合，让 35 名自行车志愿者在 0.4 公里的下坡路上骑行，一次戴头盔，一次不戴头盔。与实验中佩戴头盔相比，经常戴头盔的人报告的风险体验更高，而且不戴头盔时骑行速度更慢，尽管 HRV 没有相应变化。对于不习惯戴头盔的自行车手来说，戴头盔和不戴头盔时的速度、感知风险或任何其他指标都没有变化。这些发现与以下观点一致：那些经常戴头盔的人认为戴头盔会降低风险，因此会更快地骑车，从而补偿了风险。这为那些呼吁谨慎使用头盔法的人提供了一些支持。
