Effect of phonological processing on temporal processing

Many studies have reported that the effect of concurrent nontemporal processing on time estimation depends on the difficulty of the nontemporal task. The perceived duration of a given temporal interval decreases as the difficulty of the concurrent nontemporal task increases. A question thus arises as to whether any kind of nontemporal task will have the same effect on temporal processing. Two experiments were conducted in which the level of the nontemporal task demand was systematically varied. In Experiment 1, the effect of phonological processing on concurrent time estimation was shown to vary linearly with the number of items to be processed. Experiment 2 showed that the concurrent time estimation did not vary with the level of figural processing demands. This suggests selective interference with temporal processing on the part of concurrent phonological processing.