The Role of Inhibition in Young Children’s Performance on the Tower of London: A Computational Study

A range of evidence supports the view that processes underlying high-level cognitive tasks are diverse. Miyake et al (2000) offer the possibility of grounding some of these notions in three mechanisms: inhibition, shifting and updating. Indeed, numerous claims indicating a key role of inhibition in problem solving tasks such as the Tower of London (ToL) has accrued. But, explicit accounts of the roles such mechanisms assume are lacking. Using the data from a behavioural study concerned with the problem solving performance of 3-4 and 5-6 year olds on the ToL, a series of four computational models are developed. Their overall aim is to develop and explore one role of inhibition in accounting for differences of performance in younger and older children on the ToL. Performance is evaluated against four criteria: (1) the number of moves made (2) the number of colour balls in the correct place (3) whether the configuration was achieved and (4) whether rule breaks were committed. These measures afford the basis for further specific improvements to be proposed for each successive model and comparisons made against the behavioural data reveal each model to provide a greater degree of fit. The performance of the final two models is found to mirror important qualities of the younger and older children. This paper argues that these data indicate the possibility that younger children’s poorer performance on ToL tasks may be a result of their failure to inhibit basic moves, rather than the absence of specific cognitive strategies.