The current study expands upon previous research that has demonstrated transfer of training from action video games (AVGs) to laboratory tasks that require visual selective attention (Green, Li & Bavelier, 2009 for review). Here, the potential of AVG training was further examined by measuring visuo-spatial discrimination performance and auditory-spatial discrimination performance under varying conditions of stimulus uncertainty. To this end, 46 participants (23 expert AVG players, 23 novices) completed a visual and an auditory discrimination task, and accuracy and reaction times were recorded. Expert participants were expected to possess superior discrimination skills overall and were expected to be less affected by stimulus ambiguity. Neither mean error rate nor mean reaction time differed due to group expertise level, and both experts and novices were equally slowed and made less accurate when stimulus ambiguity was increased. Despite the lack of mean group differences, experts demonstrated faster reaction times during the visual discrimination task than during the auditory discrimination task, whereas novices did not. This interaction suggests that AVG training results in enhancement to spatial discrimination skills selectively in the visual modality, while spatial auditory processes are unaffected.