Abstracts

Rationale: The disconnection syndrome following complete section of the corpus callosum (CC) has been well documented. The effects are dramatic for lateralized cortical functions, whereas over-learned motor skills requiring bimanual coordination are typically preserved. To our knowledge, cognitive tasks requiring complex bimanual coordination, such as video games, have not been studied in this population. We report pre- and postoperative performance on three video games by a patient undergoing complete CC section. Methods: The patient is a 30 y.o. r.h. male epilepsy patient who underwent anterior 2/3 CC section in 2004. Due to continued seizures, he was scheduled for completion of the CC section in March 2008. Video game performance was assessed pre- and postoperatively using three different games, including Galaga, a shooter arcade game, Mario Kart 64 (MK64), a racing game, and Super Mario Bros. (SMB), a platform game. Following a brief practice period, 3 repetitions of Galaga and MK64 and one complete game of SMB were performed. Mean scores or total points were calculated. Disconnection syndrome was also assessed before and after surgery in both visual and tactile modalities. Uni-manual performance on visual-spatial tasks, reaction time, and psychomotor speed was assessed for both hands. Results: Preoperative performance on all tasks was largely within normal limits. Following surgery, the patient demonstrated classic disconnection symptoms, including an inability to name objects presented to his left visual field or left hand, and clear left hand advantage for visual-spatial tasks. Video game performance indicated similar (MK64) or better scores (Galaga; 48% improvement) on two of the three games and a worse score on SMB (41% decline). Behavioral observations suggested that the patient had difficulty using his right thumb on the keypad and he sometimes used his left thumb on the right side of the controller. Some learning during SMB was demonstrated. No significant differences were detected in reaction time or psychomotor speed with either the right or left hands following surgery. Conclusions: Despite complete CC section and the expected disconnection syndrome, the current case demonstrates largely preserved proficiency on two of three video games with variance apparently due to game type. Primary shooter and racing games may be primarily controlled with the left hand, representing the more spatially proficient right hemisphere, with minimal coordinated activity required from the right hand, whereas the platform game appears to require increased coordination and possibly more complex executive decision making for successful completion. Behavioral observations suggest the ability to improve bimanual coordination with practice, within the context of a video game, raising possibilities for future research on the cognitive aspects of video game performance and the use of video games for cognitive rehabilitation following brain injury.