Vigilance in a long-term cognitive computing task: The effects of subject strategy and screen colour on performance

The purpose of this study was to determine whether a vigilance decrement would occur in a cognitively-demanding computer task, and whether the strategy employed by the subject and/or the colour complexity of the screen would affect observed performance levels. Adult-aged subjects (N=60) were randomly assigned to one of three colour conditions (e.g. monochromatic, moderately-coloured, multicoloured) and asked to complete twenty consecutive games of a computerized memory task. Data were gathered by the computer, and subject strategies were determined from the data printouts. Results suggested that subject strategy, but not colour, influenced the overall level of performance and the performance decrement observed over time. Those employing a verbal rehearsal strategy outperformed all other groups by completing the task with the fewest mean errors in the shortest mean time period. Those using a consistent chunking or a variable chunking method were the next best, while those using a combined strategy (chunking and random) or a random technique performed least well. In general, a vigilance decrement was observed.