Rabi Rahel, Chow Ricky, Paracha Shahier, Hasher Lynn, Gardner Sandra, Anderson Nicole D, Alain Claude
Baycrest Centre, Rotman Research Institute, Toronto, ON, Canada.
Department of Psychology, University of Toronto, Toronto, ON, Canada.
Front Aging Neurosci. 2022 Mar 11;14:821043. doi: 10.3389/fnagi.2022.821043. eCollection 2022.
Time of day (TOD) influences on executive functions have been widely reported, with greater efficiency demonstrated at optimal relative to non-optimal TOD according to one's chronotype (i.e., synchrony effect). Older adults (OAs) show declines in inhibitory control and are more sensitive to the effects of circadian variation on executive functioning. To date, no studies have investigated the effects of TOD and aging on executive functioning using electrophysiological measures. The present study investigated the effects of aging and TOD on the neural correlates of inhibitory processing (N2 and P3) using event-related potentials (ERPs). Go-NoGo and Flanker tasks were administered to 52 OAs of morning chronotype and 51 younger adults (YAs) of afternoon-to-evening chronotype who were randomly assigned to morning or afternoon test sessions, with the optimal TOD for OAs in the morning and for YAs in the afternoon/evening. While behavioral results demonstrated no TOD effects, ERPs indicated synchrony effects. Both YAs and OAs showed greater modulation of Go-NoGo N2 and greater P3 amplitude during the non-optimal than optimal TOD, consistent with the synchrony effect. For the Flanker task, age differences in P3 amplitude were only apparent during the non-optimal TOD. These results suggest that processes associated with inhibitory control are differentially affected by TOD and aging, with age-related reductions in inhibitory efficiency during off-peak test times on measures of interference control. These findings highlight the sensitivity of ERPs to detect TOD effects in the absence of behavioral differences, confirm more pronounced TOD effects in OAs relative to YAs on ERP measures of interference control, and reinforce the need to assess and control for circadian typology in research studies.
一天中的时间（TOD）对执行功能的影响已有广泛报道，根据个体的昼夜节律类型，在最佳TOD时比非最佳TOD时表现出更高的效率（即同步效应）。老年人（OA）在抑制控制方面表现出下降，并且对昼夜节律变化对执行功能的影响更敏感。迄今为止，尚无研究使用电生理测量方法来研究TOD和衰老对执行功能的影响。本研究使用事件相关电位（ERP）来研究衰老和TOD对抑制加工的神经相关性（N2和P3）的影响。对52名早晨型的老年人和51名下午至晚上型的年轻人进行了Go-NoGo和侧翼任务，他们被随机分配到上午或下午的测试时段，老年人的最佳TOD是上午，年轻人的最佳TOD是下午/晚上。虽然行为结果未显示TOD效应，但ERP显示出同步效应。年轻人和老年人在非最佳TOD期间比最佳TOD期间都表现出对Go-NoGo N2的更大调节和更大的P3波幅，这与同步效应一致。对于侧翼任务，仅在非最佳TOD期间P3波幅的年龄差异才明显。这些结果表明，与抑制控制相关的过程受到TOD和衰老的不同影响，在非高峰测试时间，与年龄相关的抑制效率在干扰控制测量中有所降低。这些发现突出了ERP在检测无行为差异时TOD效应的敏感性，证实了在干扰控制的ERP测量中，老年人相对于年轻人的TOD效应更明显，并强调了在研究中评估和控制昼夜节律类型的必要性。
