This study aimed to measure karate playersʼ contingent negative variation (CNV) and P3 and to evaluate their information processing when predicting a temporally shielded punch. Based on their experience of karate competition, participants were divided into two groups: an expert group of 11 people belonging to the A university karate club and a novice group of 13 people without karate competition experience. This study employed a choice reaction task and used the karate videos as stimuli. Participants were told to press a button with their right hand if the video showed an upper punch and with their left hand if it showed a middle punch. The measurement indices were the visual analogue scale (VAS) score for task difficulty, correct answer rate, reaction time, CNV, and P3. The results showed that the reaction time of the expert group was significantly shorter than that of the novice group. Similarly, the P3 latency of the expert group was significantly shorter than that of the novice group, indicating that the expert group was quicker to evaluate the stimulus during the prediction of the punch. Nevertheless, there was no significant difference in CNV amplitude and P3 amplitude between the expert and novice groups, indicating that the same level of cognitive processing took place between the expert and novice groups during the video presentation. This suggests that the expert group is able to perform better at a certain level of brain activity. Therefore, it is clear that the expert group in this study is able to respond quickly by appropriately adjusting their brain activity in the cognitive and motor preparation stages during the prediction of the punch.