Study methods
Participants
Thirty-one children (16 female and 15 male) between the age of 30 and 58 months (Mean
age = 47.65 months, SD age = 6.39 months), who were enrolled at the University of
California, Berkeley, Harold E. Jones Child Study Center, participated in the study.
Parental permission was obtained from all children prior to participation via a consent
form. All children were tested at the Child Study Center by authors of the study.
Twelve adults between the age of 21 and 33 years (Mean age = 25.39 years, SD
age = 4.34 years) also participated in the study. Adult participants naı¨ve to the project
were recruited through word-of-mouth, and were primarily students at the University of
California, Berkeley. Adults played a procedurally identical version of the game as the
children, except that the game was run from a web browser rather than on the tablet. Every
asset and all sub system functions were the same on the web browser and on the tablet, but
the size of the screen was larger in the web browser version. The motivation for testing a
group of adults was to determine whether our game-based version of MOT replicated
previous object tracking limits established from laboratory-based MOT tasks, thereby
Procedure
The testing was done in a room adjacent to the children’s main classroom, during their
regularly scheduled ‘‘choice time’’ activity period. The room provided familiarity for the
children yet privacy from the main classroom activity. There was a maximum of three units
present in the testing room and maximum of three children in the room at a time. Although
there were up to three children in the testing room, each child was given his or her own
device and was invited to play the game on his or her own pace at different corners of the
room. Each child was also invited to play the game as long as they wished.
Testing was repeated across multiple days spanning 1–5 school days between tests.
While we had originally planned to keep the frequency of exposure to the game consistent
among children over time, it was difficult to control the duration between the tests, as
children were absent due to illness or other scheduling conflicts.
There were two researchers present at any given time. On the first day, when the game
was introduced to the children, the researcher introduced the basic rules of the game.
‘‘Follow the lady bug (demonstrating the child that s/he should follow it with their eyes and
not with their fingers). Wait until it stops moving (showing the child not to touch the
ladybug until it stops moving). Catch the ladybug, but not the spider (showing the child to
touch the ladybug).’’
validating our measure.