Twenty-two children (6 to 10 years old, 10 boys) participated in a 4-week program with two 45-minute computer periods and two 45-minute exercise periods each day at the Chinese National Sports University in Beijing after parents provided informed written consent consistent with University procedures. Children were either enrolled by their parents as paid participants, referred from a school for children of migrant workers, or referred from a psychiatric clinic for children with ADHD or related problems with approximately equal numbers in each group. Nineteen of the 22 who enrolled completed the program. Two of the children who did not complete the program were a brother and sister from the school for children of migrant workers, and the third had been enrolled by his parents. There were three computer exercises. In the first, children used the mouse to follow a ball bouncing around the screen and click on it when the ball turned the “target” color. The speed at which the ball moves is adaptively tracked. Other dimensions of difficulty include the duration of color changes, the complexity of the rules defining targets and the number of balls on the screen. At lower levels, the target color is indicated on the computer screen. At more advanced levels the target depends on the previous color of the ball — e.g., when the ball turns the same color twice in succession, the second is a target. At still more advanced levels there are two, and then three balls on the screen. In the second game, butterflies carry signs with pictures and the children have to click on pictures in a specified category. The speed at which the butterflies move across the screen is adaptively tracked. Other dimensions of difficulty include the number of butterflies on the screen and the complexity of category definitions. In the third game children see objects or numbers in three boxes, and choose a figure or number to put in a fourth box that fits with the pattern formed by the existing three. The time allowed to respond is adaptively tracked. Other dimensions of difficulty include the complexity of the pattern to be identified and the position of the missing element.
The physical exercises were designed to require the same eight core cognitive capacities as do the computer exercises. For example, running in a team relay race while balancing a bean bag on the head required the child to sustain attention on the balancing and inhibit the tendency to run in a manner and as fast as he or she would without the bean bag, and to do this in the context of exhortations from other children to run as fast as possible. Working memory was engaged by learning Chinese martial arts movement sequences. Multiple simultaneous attention was engaged by simple juggling with two balls.
Cognitive function was assessed on the first and last days of the program with the Flanker and DCCS tests of executive function (NIH Toolbox, Weintraub et al, in press), Go No-GO test (locally programmed), the Hungry Donkey test of delayed gratification (Crone, www.brainanddevelopmentlab.nl), Digit Span, California Verbal Learning Test children’s version (CVLT), and the Verbal Fluency test (VF). Different versions of the CVLT were used at the two time points, counterbalanced across subjects. All data acquisition, processing and analysis was done by Professor Zhang Yi and Song Jia from the psychology department at the National Sports University. Neither Dr. Zhang or Ms. Song were involved with the development of the computer or physical exercises.