Gabay, Y. 1 , Karni, A. 1 & Holt, L. . 2
1 University of Haifa
2 Carnegie Mellon University
Consolidation processes whereby new knowledge is mastered 'offline' have been shown in multiple laboratory tasks, as well as in clinical settings. Here we tested whether consolidation processes can be triggered by incidental learning of sound categories. Participants' performance in a visuo-motor task in which a visual target could appear, randomly, in any of four screen locations to be detected and responded to, was tested for acquisition, overnight consolidation phase gains, and ten-day retention. Throughout acquisition acoustically variable sound exemplars from a set of four categories preceded the appearance of visual targets such that sound category identity perfectly predicted the upcoming visual target's location. This relationship was not brought to participants' attention, and the sounds were not necessary for task performance. Practice resulted in robust overnight increases in task performance and sound category dependency (i.e., there were increasing speed costs in task performance when sounds were unavailable) as well as gains in explicit categorization of novel sound category exemplars. These effects were robustly retained. More variable auditory input resulted in earlier establishment of sound category dependency in performance. Thus, offline processes can be triggered even for incidental auditory input and lead to long-term category knowledge.