Discussion
This study aimed to examine the moderating effect of sport skill levels (ETT, ATT, and nonathletes) on behavioral and neuroelectric performance in fundamental visuospatial tasks. To address this issue, we modified non-sports-related cognitive tasks ( Müller & Knight, 2002 ) to assess the disparities between visuospatial attention and working memory of athletes and nonathletes with varying levels of sport skill. In addition, the neural mechanism of athletes with varying levels of competence was investigated. Table tennis players exhibited reduced reaction times and accuracy-adjusted RT than nonathletes in both the visuospatial attention and memory conditions, regardless of their skill level. However, there was no difference between the two athlete groups. In addition, independent of task conditions, ETT demonstrated a greater P3 amplitude than ATT, and both athletes demonstrated a greater P3 amplitude than non-athletes. The results demonstrate that table tennis players exhibit significantly enhanced visuospatial abilities under all tested conditions. Furthermore, the ETT data suggest this superiority may be attributed to the efficient allocation of neural resources during the processing of visuospatial information. Additionally, we found a negative correlation between P3 amplitude and daily training hours in the attention condition. This suggests that a longer daily training duration might result in a smaller P3 amplitude, while a shorter training duration might lead to a larger P3 amplitude.

Regardless of task condition, the RT of both levels of table tennis players was shorter than that of nonathletes. These findings are consistent with those of previous research utilizing non-sport-related visual-spatial tasks ( Wang et al., 2015 ; Wang, Guo & Zhou, 2016 ; Chueh et al., 2017 ; Guo, Li & Yu, 2017 ). These results suggest that table tennis players (average ETT 654.67 ms and average ATT 655.6 ms) are quicker than nonathletes at identifying information matching and selecting responses (average 734.06 ms). Compared to nonathletes, table tennis players have better attention deployment when performing tasks of uncertain stimulus and matching identification, which facilitates faster response selection ( Hung et al., 2004 ; Guo, Li & Yu, 2017 ). However, visual spatial processing may be improved through sports training ( Voss et al., 2010 ). Current findings indicate that table tennis players respond more quickly than nonathletes to general visuospatial tasks, supporting the broad transfer hypothesis and the notion that training specific cognitive skills can enhance performance on cognitively relevant untrained cognitive tasks ( Furley & Memmert, 2010 , 2011 ; Voss et al., 2010 ).

By evaluating P3 latency, the current study found no statistically significant differences between groups. Comparing athletes and nonathletes ( Chueh et al., 2017 ) and physical activity participants and sedentary controls on comparable visuospatial tasks, this result was consistent with previous research ( Wang & Tsai, 2016 ). Interestingly, previous research has found no significant difference in the P3 latency between athletes and non-athletes; however, a group difference was observed in the P3 amplitude during sport-specific and non-sports-related visuospatial attentional cueing tasks ( Chueh et al., 2017 ; Wang & Tu, 2017 ). Thus, we hypothesize that table tennis players improve visuospatial cognitive performance by modulating the allocation of neural resources to task-relevant stimuli, but not by enhancing neural processing speed during stimulus evaluation/classification.

However, the present study went one step further by demonstrating that the enhanced P3 amplitude was linearly related to the level of table tennis expertise. Specifically, we observed that ETT players showed the largest followed by ATT, with nonathletes showing the smallest amplitude. Greater P3 amplitudes reflect the amount of attention ( Pontifex, Hillman & Polich, 2009 ) and allocation of attention resources to behavior related stimuli ( Milne et al., 2013 ). This finding is consistent with a previous study showing that athletes (open skill and closed skill) exhibit greater P3 amplitudes in visuospatial memory tasks compared to nonathletes ( Chueh et al., 2017 ), this suggests that sports training may be promote to cognitive domains with higher mental loads (such as memory) by modulating the allocation of neural resources to task-related stimuli. Similar results were found for racket sports, indicating that badminton players responded faster and had a greater P3 amplitude than nonplayers in the action anticipation task ( Jin et al., 2011 ; Wang & Tu, 2017 ). The authors interpreted the P3 amplitude to indicate that players may devote more attention resources to memory representations associated with badminton, which is conducive to action anticipation processing speed. In addition, Peng et al. (2022) demonstrated that table tennis players had superior spatial cognitive processing and task performance than nonathletes, and that the P3 amplitude was substantially greater in the right hemisphere than the left. This suggests that the advantage of table tennis players is due to the neural activity of the right hemisphere, which is conducive to spatial location processing with attention. Moreover, these findings are consistent with current research, in which it was demonstrated that ETT athletes elicited a greater P3 amplitude than ATT athletes, suggesting that they devote more neural resources to the visuospatial attention and memory task. This indicates that table tennis players have a more effective deployment of their attention, which reflects a greater allocation of neural resources ( Hung et al., 2004 ). The present study corroborates and extends upon the findings of Scharfen & Memmert (2019) , demonstrating that the level of sports skill significantly moderates cognitive function, with observed effect sizes ranging from small to medium. A notable group effect was detected (η 2 = 0.229), highlighting a pronounced impact on P3 amplitude among table tennis players (ETT, 12.61 µV > ATT, 9.64 µV > nonathletes, 6.07 µV). This underscores the capacity of athletes in sports groups to effectively modulate neural resource allocation. The enhanced structural and functional brain plasticity associated with prolonged training in specialized sports, such as table tennis, potentially augments foundational visuospatial processing capabilities ( Zhang et al., 2021 ). The distinctive traits of table tennis players—rapid response times, precise motor coordination, and specialized cognitive processing ( Gu et al., 2021 ; Guo, Li & Yu, 2017 )—are pivotal to their superior performance, underscoring the integral relationship between fundamental visuospatial skills and increased neural resource processing. This relationship is further affirmed by the modulation of neural resources contingent upon sports skill level.

Moreover, this study employed correlation analysis to explore the nexus between sports training and P3 components more deeply. A negative correlation was observed between Cz-P3 amplitude and daily training hours under attention conditions, indicating that extended training durations may correspond to diminished attentional resources, as evidenced by reduced Cz-P3 amplitude. Conversely, shorter training durations were associated with larger Cz-P3 amplitudes, suggesting an increase in attentional resources. This finding diverges from previous observations and posits that athletes might experience cognitive adaptation through prolonged sports training, which is integral for optimizing sport performance ( Furley & Memmert, 2011 ; Furley, Memmert & Schmid, 2013 ). However, the potential for a cognitive plateau—wherein the benefits of training plateau or diminish beyond a certain threshold ( Lampit et al., 2014 )—emerges with excessive training. Symons, Bruce & Main (2023) and Xu et al. (2022) have suggested that adjustments in training frequency are necessary to sustain training effects, especially in the face of risks such as cognitive plateau (decline) and the impacts of sleep deprivation, including decreased P3 amplitude. The empirical evidence suggests that table tennis players, averaging 3–5 h of training daily, may encounter significant physical and cognitive fatigue due to the demanding nature of the sport. Thus, the potential detriments of prolonged high-intensity training might counterbalance the cognitive benefits of such activities. To circumvent these challenges, athletes are advised to judiciously manage their training regimens by modulating intensity, duration, and frequency to preserve and enhance cognitive processing capabilities, thereby ensuring peak athletic performance ( Symons, Bruce & Main, 2023 ). Nonetheless, the interpretations drawn from our correlational analysis should be approached with caution. While these associations are compelling, they do not establish causality. Future investigations are warranted to verify these relationships and elucidate the mechanisms underlying the interaction between training variables (frequency, intensity, duration) and P3 amplitude among table tennis athletes.

Some research limitations and future recommendations should be mentioned. Firstly, while our research demonstrates that table tennis players possess superior fundamental visuospatial processing capabilities, it raises the question of whether individuals with naturally stronger visuospatial cognitive functions are more inclined to excel in sports training. Due to the inherent limitations of the cross-sectional approach adopted in this study, the causal relationship between sports training and enhanced cognitive performance remains ambiguous. Consequently, there is a compelling need for future investigations to employ longitudinal methodologies. Such studies should aim to establish a definitive causal link by tracking cognitive changes in individuals who undergo specialized table tennis training, compared to those without such training, in a controlled and randomized setting. Second, previous research has demonstrated that table tennis players have superior cognitive functions, including response inhibition ( You et al., 2018 ), attentional flexibility ( Hung et al., 2004 ; Wang, Guo & Zhou, 2016 ), and visuo-perceptual abilities (for a meta-analysis, see Scharfen & Memmert, 2019 ). This study was limited to the relationship between an athlete’s talent level and visual-spatial tasks and was unable to summarize whether there are differences in other cognitive function performance and neural activity mechanisms, which requires further investigation. Third, previous research has demonstrated that gender influences visuospatial processing ( Hugdahl, Thomsen & Ersland, 2006 ). A recent meta-analysis suggested that participants measuring cognitive function were predominantly male athletes, and the absence of female athletes may have reduced the specificity of detection ( Scharfen & Memmert, 2019 ), with some studies recruiting only a single gender ( Wang et al., 2015 ; Wang & Tu, 2017 ). It can be observed that the gender of recruited athletes is inconsistent, which may be one of the factors contributing to the variable cognitive performance. The current study recruited an equal number of male and female participants for each group, but it must be determined in the future whether gender influences cognitive performance. Finally, while this study focused on athletes’ training years, weekly practice frequency and daily hours over the past 6 months, this timeframe might be limited. Future research should delve deeper into long-term training methodologies, encompassing aspects like intensity, duration, frequency, training plans, and the nature of training specifically, whether it includes cognitive tasks ( Nakata et al., 2010 ). Such studies could further explore how these training methods influence sport skill levels.