en Computational Neuroscience Computational Neuroscience Original Original <b> Introduction:</b> Computer games have attracted remarkable attentions in general publics with different cultures and their effects are subject of research by cognitive neuroscientists. In the present study, possible effects of the game Fifa 2015 on cognitive performance, hormonal levels, and electroencephalographic (EEG) signals were evaluated in young male volunteers. <div><b>Methods:</b> Thirty two subjects aged 20 years on average participated mutually in playing computer game Fifa 2015. Identification information and general knowledge about the game were collected. Saliva samples from the contestants were obtained before and after the competition. Perceptive and cognitive performance including the general cognitive health, response delay, attention maintenance, and mental fatigue were measured using PASAT test. EEG were recorded during the play using EEG device and analyzed later using QEEG. Simultaneously, the players’ behavior were recorded using a video camera. Saliva cortisol levels were assessed by ELISA kit. Data were analyzed by SPSS program. </div><div><b>Results: </b>The impact of playing computer games on cortisol concentration of saliva before and after the game showed that the amount of saliva plasma after playing the game has dropped significantly. Also the impact of playing computer games on mental health, before and after the game indicated that the number of correct answers has not changed significantly. This indicates that sustained attention has increased in participants after the game in comparison with before that. Also it is shown that mental fatigue measured by PASAT test, did not changed significantly after the game in comparison to before that. The impact of game on changes in brain waves showed that the subjects in high activity state during playing the game had higher power of the EEG signals in most of the channels in lower frequency bands in compared to normal state. </div><div><b>Discussion:</b> The present study showed that computer games can positively affect the stress system and the perceptual-cognitive system. Even though this impact was not significant in most cases, the changes in cognitive and hormonal test and also in brain waves were visible. Hence, due to the importance of this matter, it is necessary to create control systems in selecting the types of games for playing. </div> Cognitive, EEG, Saliva, Cortisol, Video Games 193 201 http://bcn.iums.ac.ir/browse.php?a_code=A-10-724-1&slc_lang=en&sid=1 Hamed Aliyari Hamedaliyary@ut.ac.ir 1370031947532846005738 1370031947532846005738 No Department of Electrical, Biomedical and Mechatronics Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran Masoomeh Kazemi mkazemih@yahoo.com 1370031947532846005739 1370031947532846005739 No Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Elaheh Tekieh elahehtekieh@yahoo.com 1370031947532846005740 1370031947532846005740 No Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Maryam Salehi maryam.salehi60@gmail.com 1370031947532846005741 1370031947532846005741 No Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Hedayat Sahraei hsahraei1343@gmail.com 1370031947532846005742 1370031947532846005742 Yes Baqiyatallah University of Medical Sciences Mohammad Reza Daliri daliri@iust.ac.ir 1370031947532846005743 1370031947532846005743 No Department of Electrical Engineering, University of Science and Technology ,Tehran, Iran Hassan Agaei sayyedagha313@gmail.com 1370031947532846005744 1370031947532846005744 No Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Behroz Minaei b-minaei@iust.ac.ir 1370031947532846005745 1370031947532846005745 No School of Computer Engineering, University of Science and Technology ,Tehran, Iran Reza Lashgari e_tekieh@yahoo.com 1370031947532846005746 1370031947532846005746 No Department of Electrical Engineering, University of Science and Technology ,Tehran, Iran Nahid Srahian sarahiannahid@yahoo.com 1370031947532846005747 1370031947532846005747 No Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Mohammad mehdi Hadipour mm.hadipour@gmail.com 1370031947532846005748 1370031947532846005748 No Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran. Mostafa Salehi hamedaliyary@gmail.om 1370031947532846005749 1370031947532846005749 No Industrial Engineering Department, K.N.Toosi university and technology Asghar Ranjbar Aghdam hamedaliyary@yahoo.com 1370031947532846005750 1370031947532846005750 No From Daj Scientific co-Research dept