Author(s): VON HERTLEIN, D., LABORDE, S., Institution: GERMAN SPORT UNIVERSITY COLOGNE, Country: GERMANY, Abstract-ID: 1338

Introduction
Critical Flicker Fusion Frequency (cFFF), the threshold at which a blinking LED light is seen as constant, is discussed as a diagnostic for cognitive function in clinical and extreme environments1. Rapid cognitive assessment can be vital for health and safety monitoring in environments like diving and mountain climbing or in contact sports where it is necessary to protect players and decide readiness to play following head impact2. Clinical research showed promising results for various cognitive domains, however, specific cognitive functions, such as core executive functions (EFs) and higher-order processes, which are highly relevant in sport contexts, remain insufficiently characterised. Therefore, our study aimed to assess the relationship between EFs and cFFF performance on Flanker, 2-Back, and Tower-of-London tasks.
Methods
cFFF performance was assessed in 44 healthy participants (female = 23; Age = 24.6±3.8) in a counterbalanced design. Vagally-mediated heart-rate variability (vmHRV), indexed by RMSSD, served as a control variable, as vmHRV has been associated to cognitive performance3,4. HRV was recorded using an ECG device (Bittium Faros). Repeated-measures ANOVA was calculated for pre & post cFFF differences and linear regression modelling for cognitive performance on the factors reaction time, accuracy, time-to-completion and number of necessary moves.
Results
cFFF values decreased significantly after cognitive tests for the Flanker task (p= <.0001). Post cFFF on the other tests was always lower but was not statistically significant. No correlation was observed between cFFF and the parameters of cognitive performance for the Flanker task (p = .11, r2 = .06), the 2-back task (p = .32, r2 = .023), and the Tower-of-London task (p = .15, r2 = .048). Similarly, vmHRV showed no significant result for the prediction of cognitive performance for the Flanker- (p = .59, r2 = .025), the 2-Back- (p = .63, r2 = .022), and the Tower-of-London tasks (p = .07, r2 = .164).
Discussion
Our findings suggest no direct correlation between cFFF and specific cognitive functions. Thus, cFFF might be more relevant as an indicator for global brain states, where cFFF represents general neural functioning and task-readiness. Reduction in cFFF performance over time likely reflect attention detriments or cognitive processing changes. Hence, long-term baseline measurements may still allow cFFF implementation based on individual response behaviour and coping in underwater, altitude or brain injury contexts. Further research is required on the interaction of the cFFF diagnostic tool with arousal, cognition, and vmHRV to improve understanding of the interaction of those variables as well as the intra-individual performance variability from stress or fatigue.

¹Mankowska et. Al (2021).DOI:10.3390/medicina57101096
²Fong et. Al (2021).DOI:10.3791/62082
3 Mosely & Laborde (2022).DOI:10.1080/1750984X.2022.2092884
4 Thayer et. Al (2009). 10.1007/s12160-009-9101-z