Effects of spatial coding on speed of information processing

A choice reaction time experiment was carried out to study the effects of spatial coding on the speed of information processing. In the experiment, subjects had to indicate whether a target stimulus was present amongst a number of other stimuli. Spatial coding was varied over 4 conditions, i.e. random, sequential order, line matrix and 3x3 matrix, while two kinds of symbols were used, i.e. digits and geometrical shapes. The results showed that, using digits as symbols, only the 3x3 matrix resulted in shorter reponse latencies. Using geometrical shapes all three types of spatial coding resulted in shorter response latencies. Differences between digits and shapes disappeared when the information was presented in a line or 3x3 matrix, indicating that subjects only searched for position and presence regardless of which symbol there happened to be.