On the locus of dual-task interference during encoding

Abstract

Jolicoeur & Dell'Acqua (1998) demonstrated that encoding a few briefly presented masked characters for later report can reduce significant interference in a concurrent speeded tone task. This result implies that encoding requires a capacity limited cognitive mechanism also required for the tone task. Six experiments explore the nature of this capacity limited cognitive mechanism using the locus of cognitive slack logic (Pashler & Johnston, 1989; McCann & Johnston, 1992). The combined results indicate that the capacity limited cognitive mechanism involved in encoding takes the form of a processing bottleneck that affects a stage after rudimentary perceptual processing but before response selection. A model is proposed which assumes a processing bottleneck at the stage where implicitly coded stimulus information is explicitly coded by the observer, a stage referred to as 'short-term consolidation' (STC). The implications of these findings on other phenomena in the dual-task literature are also discussed.