he window area was light gray, and the outer section of the screen was black. In the other half of the trials, there was no window, and the entire screen was light gray.Participants were individually tested four times within a 1-week period. The first session was a practice session, in which participants were taught the basic requirements of the task. In a very few cases, subjects participated in an extra practice session. Sessions 2-4 were the testing sessions. In the practice session, the participants were administered 50 trials with baseline conditions. Each trial was preceded by a tone approximately 1 second that sounded to alert the child to the presentation of the stimuli. The stimuli were displayed immediately on termination of the tone and remained on the monitor until the subject responded by pressing one of the two response buttons. After each trial, there was a delay of approximately 1 second before the tone sounded to begin the next trial. During the first 20 trials, participants were given verbal feedback on he accuracy of their responses. After the session, subjects were offered a choice o small prizes, regardless of level of performance. The test sessions began with 10 practice trials, with each of the 10 test conditions being presented once. These practice trials served to reacquaint the participant with the task and to allow for questions. The practice trials were followed by 60 test trials. During the testing sessions the experimenter sat to the left of the subject. He noted at the beginning of each trial whether or not the subject was looking at the computer monitor. In addition, he noted any occurrences that may have distracted the subject from the experimental task. Trials were deleted if non-task related distractions interfered with the subjects performance.Although RT tasks often provide interesting information about accuracy versus speed trade-offs, the minimal number of errors committed by the s...
