A dual-task investigation of automaticity in visual word processing

An analysis of activation models of visual word processing suggests that fr equency-sensitive forms of lexical processing should proceed normally while unattended. This hypothesis was tested by having participants perform a sp eeded pitch discrimination task followed by lexical decisions or word namin g. As the stimulus onset asynchrony between the tasks was reduced, lexical- decision and naming latencies increased dramatically. Word-frequency effect s were additive with the increase, indicating that frequency-sensitive proc essing was subject to postponement while attention was devoted to the other task. Either (a) the same neural hardware shares responsibility for lexica l processing and central stages of choice reaction time task processing and cannot perform both computations simultaneously, or (b) lexical processing is blocked in order to optimize performance on the pitch discrimination ta sk. Either way, word processing is not as automatic: as activation models s uggest.