109 SPORT Science INTERNATIONAL SCIENTIFIC JOURNAL OF KINESIOLOGY Adel Jouini 1,2* , Bessem Mkaouer 3 , Karim Chamari 4 1. High Institute of Education (ISEFC), Virtual University of Tunis, Tunisia 2. Sports Performance Optimization, National Centre of Medicine and Science in Sports, El Menzah, Tunisia 3. High Institute of Sport and Physical Education of Ksar Said, University of Manouba, Tunisia 4. AHP Research Centre, ASPETAR, Doha, Qatar. T he Mirror Neurons System (MNS) is a cortical action perception coupling system that helps us to embody not only other individual’s intentions, but also their state of mind, which can allow subsequent interactions with the observed agent [1, 2]. Furthermore, it has been shown that MNS is directly linked to the development of social cognition [3, 4]. This social cognition is directly afected by the capacity of human face recognition. During facial expression recognition, mirror neurons fre and provide an internal simulation of the observed motor comportment that induces a similar emotion in the observer’s mind; this phenomenon is known as motor resonance [5, 6]. This motor resonance enables the identifcation of the perceived emotion, feeling [7], state [8] or action [9]. This fact is very interesting, but it is insufciently explored in sports where athletes engage all their physicals and mental abilities to achieve a better performance. Moreover, in the cited This study focuses on the efect of sport expertise and the intensity of efort on the opponent facial fatigue recognition between karate players (KD) and soccer players (SC). We hypothesize that long practice of combat sport can positively afect the ability of the opponent facial expressions processing. Nineteen karatekas and 17 soccer players participated in this study. The participants performed a facial recognition task while running on a treadmill in 5-diferent conditions (i.e., rest, 60%, 80%, 100% and 120% of maximal aerobic speed, MAS). The results revealed that motor resonance increased with the increase in the intensity of the efort. It was also revealed that KD were faster and more precise in recognizing facial expressions than SC. The advantage of KD over SC in facial expressions processing was principally present in the maximum intensity of efort conditions. In conclusion, our study showed that long-term practice of karate ensures the development of the ability of the opponent facial expressions processing. Keywords: Facial recognition, soccer, karate, motor resonance, physical efort. introduction ABSTRACT PHYSICAL EFFORT AND SPORT EXPERTISE CAN MODULATE FACIAL FATIGUE PROCESSING studies, motor resonance is examined without involving any physical efort. In modern sports, it is essential to present the athletes with an exhaustive preparation in order to improve all their physical, technical and mental skills. One of these mental skills is the recognition of the opponent’s facial expressions. In spite of the high importance attributed to the facial expressions recognition during the efort, few studies have focused on this subject. The opponent facial expressions can inform us about his fatigue state which can represent valuable information to control the efort during the competition. Furthermore, an expert in a contact sport should know if the opponent would try to dissimilate his fatigue. This ability of facial expressions recognition was never studied under diferent levels of physical efort. In this study, we compared the capacity of fatigue face expression recognition within and between karateka and soccer players. We hypothesize that the expertise in activities soliciting emotional state recognition capabilities such as combat sports would result in more efective processing of this type of information. Moreover, in collective sports (i.e., soccer), and fghting sports (i.e., karate), high demand on visual allocation of