Lack of Automatic Vocal Response Learning while Reading Aloud: An Implicit Sequence Learning Study

Research on implicit sequence learning with the Serial Reaction Task (SRT) has demonstrated that people automatically acquire knowledge about fixed repeating sequences of responses and can transfer response sequence knowledge to novel stimuli. Such demonstrations are, however, mostly limited to setups with visual stimuli and manual responses. Here we systematically follow up on scarce attempts to demonstrate implicit sequence learning in word reading. While the literature on implicit sequence learning can be taken to suggest that sequence knowledge is acquired and affecting performance in word reading, we show that neither is the case in a series of four experiments. Sequence knowledge was acquired and affecting performance in color naming but not in word reading. On the one hand, we observed slowing of voice-onset times in off-sequence as compared to regularly sequenced trials when people named the color of a centrally presented disk. Yet, hardly any effect was observed when the very same sequence of words was verbalized in word reading instead. Transfer of sequence knowledge to and from color naming was not observed, either. This contrasts with sequence learning studies with manual responses, which have been taken to suggest that a fixed and repeating sequence of responses is sufficient for learning to occur even in fast choice reaction tasks and to transfer across stimuli as long as the sequence of responses remains intact. Rather, in line with dimensional action accounts of task performance, the results underline the role of translation between processing streams for implicit sequence learning.