Enumeration versus multiple object tracking: the case of action video game players

Abstract

Here, we demonstrate that action video game play enhances subjects' ability in two tasks thought to indicate the number of items that can be apprehended. Using an enumeration task, in which participants have to determine the number of quickly flashed squares, accuracy measures showed a near ceiling performance for low numerosities and a sharp drop in performance once a critical number of squares was reached. Importantly, this critical number was higher by about two items in video game players (VGPs) than in non-video game players (NVGPs). A following control study indicated that this improvement was not due to an enhanced ability to instantly apprehend the numerosity of the display, a process known as subitizing, but rather due to an enhancement in the slower more serial process of counting. To confirm that video game play facilitates the processing of multiple objects at once, we compared VGPs and NVGPs on the multiple object tracking task (MOT), which requires the allocation of attention to several items over time. VGPs were able to successfully track approximately two more items than NVGPs. Furthermore, NVGPs trained on an action video game established the causal effect of game playing in the enhanced performance on the two tasks. Together, these studies confirm the view that playing action video games enhances the number of objects that can be apprehended and suggest that this enhancement is mediated by changes in visual short-term memory skills.

Fig. 1

(A) Enumeration accuracy—% correct and breakpoint: VGPs clearly outperform NVGPs on the enumeration task. The VGP breakpoint (the elbow in the regression line) is approximately two items beyond that seen in the NVGPs. Furthermore, the VGP advantage continues to hold even for high numerosity; (B) average response: NVGPs begin to underestimate the true number of items (bar above zero) about two items before VGPs. The relative inaccuracy of the NVGPs compared to VGPs can also be seen for all numbers of squares as the VGP bar does not begin to deviate from zero (on average perfectly correct) until around 10 items; (C) RTs: NVGPs and VGPs have very similar RTs for low numerosity, VGPs being slightly faster, but as the number of items to enumerate increases, the VGP RT becomes much greater than NVGPs. This is unlikely to represent a speed/accuracy trade-off in the conventional sense, in that longer RTs allow for more information to decay from visual memory. Instead, these results may indicate a more stable visual memory representation in the VGP population (Error bars denote SEM, *=P<0.05, **=P<0.001).

Fig. 2

(A) Enumeration accuracy—% correct and breakpoint-Action game: the action group demonstrates a clear increase both in breakpoint (by around 1.5 squares) and in overall accuracy; (B) enumeration accuracy—% correct and breakpoint-Control game: the control group showed no sign of improvement after training, thus ruling out test-retest improvements or improvements in visuo-motor control as possible hypotheses to explain the improvement in the action group (Error bars denote SEM, *=P<0.05, **=P<0.001).

Fig. 3

(A) Enumeration accuracy—% correct and breakpoint: As was seen in Section 2, VGPs show a clear advantage both in breakpoint as well as overall accuracy; (B) RT: also as was seen in Section 2, VGPs and NVGPs have extremely similar RTs for low numbers of items, but VGPs begin to take significantly longer than NVGPs as the number of items to be enumerated increases. The RT breakpoint, which offers an index of the number of items that can be instantaneously apprehended, is similar in both groups (Error bars denote SEM, *=P<0.05, **=P<0.001).

Fig. 4

Multiple object tracking performance: VGPs demonstrate a substantial increase in the accuracy with which multiple items can be tracked compared to NVGPs. The effect is most pronounced for 3–5 items to track (Error bars denote SEM, *=P<0.05, **=P<0.001).

Fig. 5

(A) Multiple object tracking performance-Action game: those subjects trained for 30 h on an action video game show a marked improvement in their MOT performance as compared to their pre-test scores; (B) multiple object tracking performance-control game: performance was identical before and after training in the control group. These results rule out test-retest as a source of confounding as well as increases in visuo-motor coordination (Error bars denote SEM, *=P<0.05, **=P<0.001).