reaction time

In volleyball, as in other sports, special attention should be paid to the individual characteristics of the athlete. However, this is often neglected. Most problems arise when the selection criteria for a role are not a player’s personal qualities, but rather their technical and tactical skills (tallness, a strong dominant arm, etc.). Here, it’s not just the player’s skills that matter, but also how they present themselves as a person. Many personal qualities are determined by a person’s genetic code, which cannot be changed. The nervous system, temperament, and character play a crucial role in success in volleyball. Athletes’ activities during volleyball are subject to many specific characteristics inherent to the game. The fast pace, the variety and unexpectedness of game situations, the interaction with teammates, the intermittent pace, and other characteristics place mental demands on volleyball players that are markedly different from those placed on, for example, a gymnast during gymnastics exercises. A volleyball player must be able to quickly and accurately navigate changing conditions, instantly switch from one situation to another, and be prepared for any actions by teammates and opponents. The time constraints of fast-paced play place high demands on reaction time and decision-making. Two main types of neuropsychological resilience can be distinguished: players with an unstable nervous system and those with an inert nervous system. In the former case, a player may involuntarily change their mental state before an important game, sometimes becoming calm, sometimes excited. It is important to properly prepare such volleyball players. High-intensity and prolonged training before the game will help them focus and distract themselves from external stress. An athlete with this type of nervous system should focus on the technique and precision of the elements they perform. In the case of an inert nervous system, training should be focused on mental work. Before the game, a volleyball player should begin psychological preparation, which will consist of positive and negative mental stimulation based on the athlete’s personal experience. When working during training or warm-ups, it’s important to emphasize the athlete’s potential dangers.

This study examined whether an 8-week progressive temporal-occlusion training program improves early anticipation of forehand drop-shot direction in badminton. Seventy-eight university students with systematic badminton training experience were randomly assigned to a progressive temporal-occlusion group, a full-information active-control group, or a regular-activity control group ( n = 26 per group); 72 completed both pretest and posttest. The two video-training groups trained twice weekly for 8 weeks. Anticipation was assessed at four occlusion points: 80 ms before racket–shuttle contact, 40 ms before contact, at contact, and 40 ms after contact. Shot-direction anticipation accuracy was the primary performance measure, and correct-response reaction time (RT) was the secondary measure. Data were analyzed using mixed repeated-measures ANOVA, planned comparisons, and trial-level sensitivity analyses. Accuracy showed a significant group × test-session interaction ( p < 0.001), whereas the group × test-session × occlusion-point interaction was not significant ( p = 0.185). Relative to the active-control group, the progressive group showed larger accuracy gains at 40 ms before contact and at contact (Holm-adjusted p = 0.048 and 0.009, respectively). For correct-response RT, the three-way interaction was significant ( p < 0.001), with larger reductions in the progressive group at 80 ms before contact, 40 ms before contact, and at contact (all Holm-adjusted p = 0.013). Thus, the progressive temporal-occlusion training program produced additional improvements in selected anticipation measures beyond those obtained with dose-matched full-information video practice. The additional accuracy gains were observed at 40 ms before contact and at contact, whereas additional RT reductions extended from 80 ms before contact to contact. Because the three-way interaction for accuracy was not significant, the apparent temporal specificity of the accuracy gains should be interpreted cautiously.

Background Cognitive differences across badminton performance levels may be task-specific rather than reflect broad executive-function advantages. Methods Ninety-six participants (33 high-level players, 31 recreational players and 32 non-badminton participants) completed word-color matching, task switching, 1-back and Raven testing. Analyses adjusted for sex, age and Raven score. Task-level MANCOVAs used Pillai’s trace, with HC3-adjusted RT models and binomial mixed models for follow-up comparisons. Additional models distinguished 1-back timeouts from accuracy among answered trials. Results Overall group effects were significant for word-color matching ( p < 0.001) and 1-back ( p = 0.011), but not task switching ( p = 0.592). High-level players responded faster in both word-color conditions than both comparison groups. Condition, response hand and response frequency were confounded, preventing an isolated interpretation of the condition RT contrast. In 1-back, timeout rates were 40.45%, 36.92% and 48.21% in the high-level, recreational and non-badminton groups; both badminton groups had lower adjusted timeout rates than the non-badminton group in both conditions. Accuracy among answered trials showed no clear group differences, and correct-response RT did not differ significantly ( p = 0.572). All-trial accuracy findings were sensitive to model specification. Conclusion High-level players showed faster word-color matching, and both badminton groups had fewer timeouts in the deadline-constrained 1-back task. The findings indicate task-specific performance differences rather than a broad executive-function advantage.

Background Athletic performance in open-skill sports depends on the efficient integration of cognitive and motor processes under dual-task (DT) conditions. Reliable measurement of these processes is a prerequisite for assessing the functional profile of young athletes (aged 13–15) and for guiding training. Objective This study examined the test-retest reliability (TRR) of center-of-pressure (COP) and fNIRS-derived cortical activation metrics across zero-load, low-load, and high-load conditions, assessed the reliability of N-back performance under the two dual-task conditions, and descriptively compared cortical activation patterns across load conditions in adolescent basketball players. Methods Twenty male adolescent basketball players completed a within-subject test-retest protocol involving two visits separated by 7 days. At each visit, participants performed quiet stance alone under the zero-load condition and concurrently with auditory 0-back and 2-back tasks under the low-load and high-load conditions, respectively. Test-retest reliability was quantified using intraclass correlation coefficients (ICCs) for COP indices and fNIRS-derived t-statistics in the bilateral prefrontal cortex (PFC) and motor cortex (MC) across all three load conditions, and for N-back accuracy and reaction time under the two dual-task conditions. Results Most indices yielded moderate-to-excellent point estimates of reliability (ICC range: 0.609–0.984), although precision varied, with several 95% confidence intervals spanning multiple reliability categories. COP whole path length, path length per unit area, and the N-back metrics showed good-to-excellent point estimates (ICC ≥ 0.784), and fNIRS-derived t-statistics in the PFC and MC reached ICCs of up to 0.984 under high-load conditions. Within the COP domain, whole path length, circumference area, and path length per unit area constitute three non-redundant indices; mean sway velocity is a duration-normalized expression of whole path length (MSV = WPL/T) and is therefore not counted as separate reliability evidence. Grand-average maps of fNIRS-derived GLM t-statistics appeared qualitatively similar across sessions. Conclusion These findings provide preliminary test-retest reliability estimates for selected multimodal neurobehavioral measures in male adolescent basketball players although reliability alone does not establish clinical utility and estimates with wide confidence intervals require confirmation in larger samples. Whether these measures can support monitoring of cognition–action coupling or inform interventions remains to be determined in future validity and responsiveness studies.

زمینه: عملکرد ورزشی در ورزش‌های مهارت باز به ادغام کارآمد فرایندهای شناختی و حرکتی تحت شرایط دو‌وظیفه‌ای (DT) وابسته است. اندازه‌گیری پایا از این فرایندها پیش‌نیاز ارزیابی نمایه عملکردی ورزشکاران جوان (۱۳ تا ۱۵ ساله) و هدایت تمرینات است. هدف: این مطالعه پایایی آزمون-بازآزمون (TRR) شاخص‌های مرکز فشار (COP) و شاخص‌های فعال‌سازی قشری استخراج‌شده از fNIRS را در شرایط بدون بار، بار کم و بار زیاد بررسی کرد، پایایی عملکرد N-back را در دو وضعیت دو‌وظیفه‌ای ارزیابی نمود و الگوهای فعال‌سازی قشری را به طور توصیفی در شرایط مختلف بار در بازیکنان نوجوان بسکتبال مقایسه کرد. روش‌ها: بیست بازیکن نوجوان پسر بسکتبال در یک پروتکل آزمون-بازآزمون درون‌گروهی با دو جلسه به فاصله ۷ روز شرکت کردند. در هر جلسه، شرکت‌کنندگان ایستادن ساکت را به تنهایی در شرایط بدون بار و به طور همزمان با تکالیف شنیداری 0-back و 2-back به ترتیب در شرایط بار کم و بار زیاد انجام دادند. پایایی آزمون-بازآزمون با استفاده از ضریب همبستگی درون‌کلاسی (ICC) برای شاخص‌های COP و آمار t استخراج‌شده از fNIRS در قشر پیش‌پیشانی دوطرفه (PFC) و قشر حرکتی (MC) در هر سه وضعیت بار و همچنین برای دقت و زمان واکنش N-back در دو وضعیت دو‌وظیفه‌ای محاسبه شد. نتایج: اکثر شاخص‌ها برآوردهای نقطه‌ای پایایی متوسط تا عالی را نشان دادند (دامنه ICC: ۰.۶۰۹ تا ۰.۹۸۴)، هرچند دقت متغیر بود و چندین فاصله اطمینان ۹۵٪ چند دسته پایایی را در بر می‌گرفتند. طول کل مسیر COP، طول مسیر به ازای واحد سطح و شاخص‌های N-back برآوردهای نقطه‌ای خوب تا عالی داشتند (ICC ≥ ۰.۷۸۴) و آمار t استخراج‌شده از fNIRS در PFC و MC در شرایط بار زیاد به ICC تا ۰.۹۸۴ رسید. در حوزه COP، طول کل مسیر، مساحت محیطی و طول مسیر به ازای واحد سطح سه شاخص غیرتکراری هستند؛ میانگین سرعت نوسان، بیان نرمال‌شده بر حسب زمان از طول کل مسیر است (MSV = WPL/T) و بنابراین به عنوان شواهد پایایی جداگانه محسوب نمی‌شود. نقشه‌های میانگین کلی آمار t مدل خطی تعمیم‌یافته (GLM) استخراج‌شده از fNIRS در جلسات مختلف به طور کیفی مشابه بودند. نتیجه‌گیری: این یافته‌ها برآوردهای مقدماتی پایایی آزمون-بازآزمون برای برخی شاخص‌های نورو‌رفتاری چندوجهی در بازیکنان نوجوان پسر بسکتبال ارائه می‌دهد، هرچند پایایی به تنهایی سودمندی بالینی را اثبات نمی‌کند و برآوردهایی با فاصله اطمینان وسیع نیازمند تأیید در نمونه‌های بزرگ‌تر هستند. اینکه آیا این شاخص‌ها می‌توانند از پایش همبستگی شناخت-عمل یا طراحی مداخلات حمایت کنند، نیازمند بررسی در مطالعات آتی روایی و پاسخگویی است.

OBJECTIVE: The present study investigated Stroop interference effects in young adult and older deaf American Sign Language (ASL) and English bilinguals with ASL and English stimuli. METHOD: Deaf ASL-English bilinguals (n = 108; aged 21-88) signed their responses in two computerized Stroop tasks, one with ASL videos of color signs and one with printed English color words. Participants saw 120 trials in each language with 84 congruent and 36 incongruent trials. RESULTS: Even though participants responded in ASL in both tasks, Stroop effects were larger with English than with ASL stimuli in both response times (RTs) and errors, a pattern of results not typically seen in spoken-language bilinguals (in which Stroop effects are often smaller between-languages than within-languages). Older participants showed larger Stroop effects than younger participants, especially in English RTs. Aging effects in error rates were not significant in either language. CONCLUSIONS: The finding of larger Stroop effects in deaf signers with English rather than ASL stimuli suggests a possibly critical role for modality of presentation in eliciting Stroop effects. Additional work is needed to determine why English is more sensitive to aging effects in deaf signers, and which language will be most sensitive for detecting cognitive impairment in this population.

هدف: پژوهش حاضر اثرات تداخل استروپ را در بزرگسالان جوان و سالمند ناشنوای دوزبانه زبان اشاره آمریکایی (ASL) و انگلیسی با محرک‌های ASL و انگلیسی بررسی کرد. روش: دوزبانه‌های ناشنوای ASL-انگلیسی (n = 108؛ دامنه سنی ۲۱ تا ۸۸ سال) پاسخ‌های خود را در دو تکلیف رایانه‌ای استروپ، یکی با ویدئوهای ASL از نشانه‌های رنگ و دیگری با واژه‌های رنگ چاپی انگلیسی، به صورت اشاره‌ای ارائه دادند. شرکت‌کنندگان در هر زبان ۱۲۰ آزمون مشاهده کردند که شامل ۸۴ آزمون همخوان و ۳۶ آزمون ناهمخوان بود. یافته‌ها: اگرچه شرکت‌کنندگان در هر دو تکلیف به زبان اشاره پاسخ دادند، اثرات استروپ با محرک‌های انگلیسی نسبت به ASL هم در زمان واکنش (RTs) و هم در خطاها بزرگ‌تر بود؛ الگویی که معمولاً در دوزبانه‌های گفتاری مشاهده نمی‌شود (که در آن اثرات استروپ اغلب بین‌زبان‌ها کوچک‌تر از درون‌زبان‌ها است). شرکت‌کنندگان سالمند نسبت به جوان‌ترها اثرات استروپ بزرگ‌تری نشان دادند، به‌ویژه در زمان واکنش انگلیسی. اثرات سالمندی در نرخ خطا در هیچ‌یک از زبان‌ها معنادار نبود. نتیجه‌گیری: یافته اثرات استروپ بزرگ‌تر در ناشنوایان اشاره‌گر با محرک‌های انگلیسی نسبت به ASL، نقش احتمالی مهمی برای شیوه ارائه محرک‌ها در ایجاد اثر استروپ پیشنهاد می‌کند. پژوهش‌های بیشتری لازم است تا مشخص شود چرا زبان انگلیسی نسبت به اثرات سالمندی در ناشنوایان اشاره‌گر حساس‌تر است و کدام زبان برای شناسایی اختلال شناختی در این جمعیت حساس‌تر خواهد بود.