Chronotype as self-regulation: morning preference is associated with better working memory strategy independent of sleep

Abstract

Study objectives We set out to examine how chronotype (diurnal preference) is connected to ability to function in natural conditions where individuals cannot choose their sleep schedule. We conducted a cross-sectional study in military conscript service to test the hypothesis that sleep deprivation mediates the adverse effects of chronotype on cognitive functioning. We also examined the effects of time of day. Methods 140 participants (ages 18-24 years) completed an online survey, including the Morningness-Eveningness Questionnaire (MEQ) and a Cambridge Neuropsychological Test Automated Battery (CANTAB). Most (n=106) underwent an actigraphy recording. After bivariate analyses, we created a mediation model (self-reported sleepiness and sleep deprivation mediating effect of chronotype on cognition) and a moderation model (synchrony between most alert time and testing time). Results Reaction times in inhibition task correlated negatively with sleep efficiency and positively with sleep latency in actigraphy. There was no relation to ability to inhibit responses. More significantly, spatial working memory performance (especially strategicness of performance) correlated positively with morning preference and negatively with sleep deprivation before service. Synchrony with most alert time of the day did not moderate these connections. No other cognitive task correlated with morningness or sleep variables. Conclusions In line with previous research, inhibitory control is maintained after insufficient sleep but with a tradeoff of slower performance. The connection between morning preference and working memory strategy is a novel finding. We suggest that diurnal preference could be seen as an adaptive strategy, as morningness has consistently been associated with better academic and health outcomes.

The Interplay of Time-of-day and Chronotype Results in No General and Robust Cognitive Boost

“…Overall, the present results are mostly in line with the findings challenging the synchrony effect on cognition (e.g., Ceglarek et al, 2021;Heimola et al, 2021Heimola et al, , 2021Knight & Mather, 2013;Lewandowska et al, 2018;Li et al, 1998;Matchock & Mordkoff, 2009).…”

“…From a positive perspective, our results can be interpreted that the synchrony effect does exist and that it would emerge in about 25% of cognitive tasks (i.e., 2/8 of our tasks). From this perspective and based on the assumption that a large portion of null-findings are not published (e.g., Kühberger et al, 2014), our findings would be broadly consistent with previous research showing mixed evidence with regards to the synchrony effect on short-term memory and working memory (e.g., Rowe et al, 2009;Schmidt et al, 2015;West et al, 2002;but Ceglarek et al, 2021;Heimola et al, 2021;Lewandowska et al, 2018). This interpretation of the findings would be valid if the circumstances under which a synchrony effect occurs and under which it does not occur were clear.…”

“…The same situation applies to working memory (i.e., the ability to manipulate and maintain information for a short duration; e.g., Baddeley, 2012). That is, some studies find evidence for a synchrony effect on working memory (e.g., Rowe et al, 2009;Schmidt et al, 2015;West et al, 2002), while other studies suggest no synchrony effect on working memory (e.g., Ceglarek et al, 2021;Heimola et al, 2021;Lewandowska et al, 2018;Schmidt et al, 2015).…”

“…For instance, evidence is mixed for tasks measuring attentional control or executive functions (i.e., the ability to maintain goal-relevant information when facing distraction; Draheim et al, 2022;von Bastian et al, 2020). While some studies present evidence for the synchrony effect on attentional control THE COGNITIVE BOOST AT THE PEAK OF CIRCADIAN AROUSAL 5 (e.g., Bennett et al, 2008;Hahn et al, 2012;Hasher et al, 2002;Intons-Peterson et al, 1998;Lara et al, 2014;May, 1999;, others are not able to detect such an effect on attentional control (e.g., Bennett et al, 2008;Heimola et al, 2021;Knight & Mather, 2013;Li et al, 1998;Matchock & Mordkoff, 2009;Schmidt et al, 2012). The same situation applies to working memory (i.e., the ability to manipulate and maintain information for a short duration; e.g., Baddeley, 2012).…”

Effects of Chronotype and Social Jet-Lag on Neurocognitive Functioning

“…As a result of the study, it was found that morningness chronotypes had a better cognitive capacity than eveningness chronotypes, with reduced P300 delay observed for both frequent and rare stimuli (Venkat et al 2020). In the study of Heimola et al it was found that working memory was associated with chronotypes, and morningness chronotypes performed better (Heimola et al 2021). A study conducted with adolescents in Japan found that 51.1% of the participants experienced ≥1 hour of social jetlag.…”