Competition between memory and perceptual tasks involving physically similar stimuli

Performance on a perceptual recognition task and a concurrently performed short-term memory (STM) task was studied. The stimuli used in the STM task were either visually similar, acoustically similar, or dissimilar to the stimuli in the perceptual task. The results demonstrated that any type of concurrent list memorization has a detrimental effect upon perceptual performance, but this effect is magnified if the stimuli used in the 2 tasks are visually similar. Acoustic similarity had no effect. The results document the fact that distinct tasks interfere, when the tasks compete for a limited total processing capacity, or when the tasks demand the same visual coding program.