The dual systems approach to category learning: How do people switch between systems?

Dual systems accounts have dominated research into human category learning. Despite this, there has been limited investigation into how people switch between proposed systems. We report an experiment which modified a popular probabilistic categorisation task (the Weather Prediction Task) in an attempt to demonstrate conditions under which such a switch could occur. The results suggested that increasing working memory load impaired categorisation performance and reduced the flexibility with which participants applied their knowledge. Importantly, no clear evidence of a switch between learning systems was found despite using a design intended to favour a shift from declarative to procedural learning. These findings pose questions for the expectation that the nature of a category structure will determine which system is engaged.