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Abstract: Purpose: Mental fatigue (MF) is increasingly implicated in elite sports, yet its characteristics and impact in real-world fencing, a highly perceptual-cognitive demanding domain, are underexplored. Methods: A 4-week single-blind, longitudinal study monitored 31 (7 épée, 13 foil, and 11 sabre; 15 females) elite fencers’ daily MF across training and competition phases before, during, and after a national championship. Subjective MF on a visual analog scale and reaction time (from 3-min Psychomotor Vigilance Test) were measured daily in the morning (baseline) and after training or competition. Self-reported individualized training variables (session rating of perceived exertion, duration, and detailed training workload demands) were collected posttraining. One-way repeated-measures analyses of variance assessed daily MF on a visual analog scale and reaction-time changes across phases. Linear mixed-effect models examined the impact of training load and specific training workloads on MF. Results: Analysis of 93 match days and 440 training days revealed that MF on a visual analog scale increased after fencing activities compared with baseline, peaking on match days (+19.34 AU, P < .001), which aligned with an impaired reaction time (+76.43 milliseconds, P < .01). On training days, overall training load (estimate = 0.02), as well as the contributions of tactical (estimate = 0.26) and physical (estimate = 0.12) workload demands, positively predicted the MF increase (all P < .001), whereas environmental demand (estimate = −0.13, P = .022) mitigated the MF elevation. Conclusions: The study highlights the prevalence of MF in elite fencers and its subsequent impact on reaction performance on competition days. The association with specific training structures provides insights for coaches and athletes to actively manage MF and optimize performance throughout a season.
Keywords: sport, cognitive fatigue, longitudinal monitoring, reaction performance, training load, combat sports
Published in DiRROS: 18.05.2026; Views: 294; Downloads: 237
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Abstract: The performance monitoring system is essential for adaptive behavior and the development of brain-machine interfaces that utilize neural feedback signals. The posterior medial frontal cortex generates different error-related potentials (ErrP), including error-related negativity (ERN), N2, and feedback-related negativity (FRN), which encode specific aspects of performance evaluation. In this study, we reexamine the hierarchical framework of error processing by investigating how low-level execution error detection and correction influence high-level outcome evaluation as reflected in FRN dynamics. Furthermore, we examine whether neural signals associated with outcome errors maintain consistent or distinct feature representations under different experimental conditions of altered feedback availability. Using a visuomotor rotation task, we manipulated the availability of visual feedback in three blocks to examine how immediate sensory error detection and corrective actions interact with outcome processing. Participants (n = 16) performed reaching movements while experiencing unexpected cursor rotations (±20° and ±40°; 20% probability) that challenged their sensorimotor control and task success. EEG recordings revealed that the FRN showed valence sensitivity in Blocks 1 and 3, while Block 2 exhibited a surprise-driven response without outcome differentiation. In contrast, posterior negativity appeared only in Blocks 1 and 3, where participants could detect and correct movement errors. This posterior response emerged on trials requiring corrective movements, regardless of final outcome, and appears to be driven by the availability of sensory feedback and error correction rather than by outcome valence. Furthermore, we demonstrate robust classification between low-level and high-level error signals and their conditional outcome-related variations, providing a foundation for more informative feedback in adaptive neural interfaces.
Keywords: error-related potentials, feedback-related negativity, performance monitoring, neural signals, brain-machine interfaces, visuomotor rotation
Published in DiRROS: 30.04.2026; Views: 323; Downloads: 368
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Abstract: Introduction Mental fatigue (MF) significantly affects both cognitive and physical performance. However, the precise mechanisms, particularly concerning neurotransmission, require further investigation. An implication of the role of dopamine (DA) and noradrenaline (NA) is stated, but empirical evidence for this theory still needs to be provided. To address this gap, we aim to investigate the role of brain neurotransmission in elucidating if, and how prolonged cognitive activity induces MF and its subsequent impact on cognitive performance. Methods This study (registration number: G095422N) will adopt a randomized cross-over design with sixteen healthy participants aged 18–35 years. The sessions include a familiarization, two experimental (DA: 20mg Methylphenidate; NA: 8mg Reboxetine) conditions, and one placebo (lactose tablet: 10mg) condition. A 60-minute individualized Stroop task will be used to investigate whether, and how the onset of MF changes under the influence of reuptake inhibitors. Attention and response inhibition will be assessed before and after the MF-inducing task using a Go/NoGo task. The integration of physiological (electroencephalography, heart rate), behavioral (attention, response inhibition), and subjective indicators (scales and questionnaires) will be used to detect the underlying mechanisms holistically. Data analysis will involve linear mixed models with significance at p<0.05. Discussion The integration of diverse techniques and analyses offers a comprehensive perspective on the onset and impact of MF, introducing a novel approach. Future research plans involve extending this protocol to explore the connection between brain neurotransmission and physical fatigue. This protocol will further advance our understanding of the complex interplay between the brain and fatigue.
Keywords: mental fatigue, neurotransmission, cognitive performance, dopamine, noradrenaline, electroencephalography (EEG)
Published in DiRROS: 10.02.2026; Views: 721; Downloads: 276
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Abstract: Brain–computer interfaces (BCIs) have the potential to enable individuals to interact with devices by detecting their intention from brain activity. A common approach to BCI is to decode movement intention from motor imagery (MI), the mental representation of an overt action. However, research-grade electroencephalogram (EEG) acquisition devices with a high number of sensors are typically necessary to achieve the spatial resolution required for reliable analysis. This entails high monetary and computational costs that make these approaches impractical for everyday use. This study investigates the trade-off between accuracy and complexity when decoding MI from fewer EEG sensors. Data were acquired from 15 healthy participants performing MI with a 64-channel research-grade EEG device. After performing a quality assessment by identifying visually evoked potentials, several decoding pipelines were trained on these data using different subsets of electrode locations. No significant differences (p = [0.18–0.91]) in the average decoding accuracy were found when using a reduced number of sensors. Therefore, decoding MI from a limited number of sensors is feasible. Hence, using commercial sensor devices for this purpose should be attainable, reducing both monetary and computational costs for BCI control.
Keywords: brain-computer interface, motor imagery, feature reduction, electroencephalogram, machine learning
Published in DiRROS: 03.04.2023; Views: 2206; Downloads: 1168
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Abstract: With advanced age, there is a loss of reaction speed that may contribute to an increased risk of tripping and falling. Avoiding falls and injuries requires awareness of the threat, followed by selection and execution of the appropriate motor response. Using event-related potentials (ERPs) and a simple visual reaction task (RT), the goal of our study was to distinguish sensory and motor processing in the upper- and lower-limbs while attempting to uncover the main cause of age-related behavioral slowing. Strength (amplitudes) as well as timing and speed (latencies) of various stages of stimulus- and motor-related processing were analyzed in 48 healthy individuals (young adults, n = 24, mean age = 34 years; older adults, n = 24, mean age = 67 years). The behavioral results showed a significant age-related slowing, where the younger compared to older adults exhibited shorter RTs for the upper- (222 vs. 255 ms; p = 0.006, respectively) and the lower limb (257 vs. 274 ms; p = 0.048, respectively) as well as lower variability in both modalities (p = 0.001). Using ERP indices, age-related slowing of visual stimulus processing was characterized by overall larger amplitudes with delayed latencies of endogenous potentials in older compared with younger adults. While no differences were found in the P1 component, the later components of recorded potentials for visual stimuli processing were most affected by age. This was characterized by increased N1 and P2 amplitudes and delayed P2 latencies in both upper and lower extremities. The analysis of motor-related cortical potentials (MR) revealed stronger MRCP amplitude for upper- and a non-significant trend for lower limbs in older adults. The MRCP amplitude was smaller and peaked closer to the actual motor response for the upper- than for the lower limb in both age groups. There were longer MRCP onset latencies for lower- compared to upper-limb in younger adults, and a non-significant trend was seen in older adults. Multiple regression analyses showed that the onset of the MRCP peak consistently predicted reaction time across both age groups and limbs tested. However, MRCP rise time and P2 latency were also significant predictors of simple reaction time, but only in older adults and only for the upper limbs. Our study suggests that motor cortical processes contribute most strongly to the slowing of simple reaction time in advanced age. However, late-stage cortical processing related to sensory stimuli also appears to play a role in upper limb responses in the elderly. This process most likely reflects less efficient recruitment of neuronal resources required for the upper and lower extremity response task in older adults.
Keywords: aging, sensoriomotor integration, event-related potential, finger and foot responses, motor-related cortical potential
Published in DiRROS: 04.05.2022; Views: 2021; Downloads: 1453
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