Parallel processing of redundant targets in simple visual search tasks.

Abstract

This study is concerned with the parallel vs serial processing issue and the closely connected limited capacity vs unlimited capacity issue in simple visual search tasks. The results of four search experiments, two “go- no go” tasks, and two “yes-no” tasks are reported. Conditions of low and high target-noise similarity were used. In all four experiments a clear redundancy gain, that is a decrease in RTs with increasing number of simultaneously presented targets, was observed. This strongly suggests parallel processing of unlimited capacity in all four tasks. Further analysis of the data, in order to investigate whether artifacts could have caused the redundancy gains, indicated an unexpected difference between “go- no go” tasks and “yes-no” tasks. For the “go- no go” tasks, unlimited capacity parallel processing could be firmly established. No firm conclusion about the mode of processing in the “yes-no” tasks reported could be reached.