Exploring interference effects during statistical learning

Abstract

This thesis examined interference effects during statistical learning (SL). SL is an implicit process where participants learn statistical regularities in an environment. Importantly, SL has been linked to key cognitive skills, such as reading and writing. The literature review highlighted that the striatum plays an important role in SL. It was hypothesized that SL would be adversely affected by concurrent tasks that also place demands on the striatum. The SL task used in this thesis contained groupings of triplet pictures. The SL task was performed incidentally, where participants were not told of the groupings until after exposure, and intentionally, where participants were informed of the groupings before exposure. The first experiment in Study 1 demonstrated that movement and exercise adversely affected incidental SL. It was speculated that the demands placed on the striatum by cycling adversely affected incidental SL. Intentional SL used on the second experiment in Study 1 was not affected by movement or exercise. It was speculated that intentional SL was less reliant on the striatum than incidental SL. Study 2 demonstrated that a prior bout of exercise did not affect incidental SL. The study was conducted as a follow up to Study 1. The first experiment of Study 3 demonstrated non-novel articulation did not interfere with incidental SL. As novel articulation has processing occur through the striatum whilst non-novel articulation does not, it was speculated the results may have been due to different levels of interference in the striatum. The second experiment of Study 3 demonstrated significant levels of intentional SL even when performing the novel and non-novel articulation tasks. It was speculated that intentional SL was less reliant on the striatum than incidental SL. The pattern of interference effects seen in the studies provides indirect evidence that the striatum plays an important role in incidental SL.