Choice Reaction Time as a Function of Set Size and Signal Frequency

This research was conducted in two experiments. The first experiment assessed whether set size for the negative and positive sets affected reaction time during a visual scanning task. The effects of signal frequency on these relationships were assessed in the second experiment. It was hypothesized that as set size increased, reaction time would increase. In addition, as signal frequency increased, it was hypothesized that reaction time would decrease. In the first experiment, 12 groups of 10 subjects each were tested varying the number of stimuli for the positive and negative sets. The second experiment tested 18 groups by varying the levels of the positive and negative set size, as well as varying the proportion of the stimuli presented for each group. Reaction time served as the major dependent variable for each group of subjects. The results indicate that the size of the positive set does affect reaction time; however, the size of the negative set does not appear to affect reaction time. As the proportion of the stimuli presented in the positive set increased, reaction time was found to decrease.