How are inhibitory demands created and avoided in developmental tasks?

This thesis investigates the creation and avoidance of inhibitory demands in inhibitory tasks. Chapter Two investigated whether inhibitory demands are lower in Stimulus Response Compatibility tasks when resisting verbal imitation than when resisting manual imitation. Preschool children took part in three experiments. Experiment 1 results were inconclusive. Experiment 2a and 2b results suggested word imitation (e.g., hear ‘dog’, say ‘cup’) is easier to inhibit than manual imitation (e.g. see |finger|, make a |fist|). Experiment 2b results support a Complexity account (Simpson et al., 2013; Simpson & Carroll, 2014): words’ complexity leads to ‘slow mapping’ between speech perception and motor production. On hearing speech, motor representations are activated only a little or not at all: verbal imitation is not automatic. Chapter Three investigates an alternative account of why verbal imitation is easy for young children to inhibit: Dissimilarity. It suggests that when words are phonologically dissimilar (e.g., ‘dog’ / ‘cup’), verbal imitation is easy to resist. Experiments 3, 4 and 5 were consistent with this proposal. Experiments 4 and 5 also showed faster responding with dissimilar words. Taken together, results support a Dissimilarity account: it easier to inhibit word imitation when planning to say dissimilar words from those heard. Chapter Four investigated why the Reverse Sort task (e.g., see |sun| card sort into |moon| card tray, see |moon| card sort into |sun| card tray’) is easier than the Grass/Snow task (e.g., hear ‘sun’ point to |moon| card, hear ‘moon’ point to |sun| card) (see Peterson et al., 2016). Specifically, Experiments 6 and 7 investigated whether preschool children’s use of an IC-avoiding conceptualisation (Simpson & Carroll, 2018) enabled them to circumvent task rules. Under Conceptualisation, task rules conceptualised as IC-avoiding will reduce inhibitory demands – and improve performance. However, results did not support this proposal. Experiment 8 investigated whether slower responding in the Reverse Sort task reduces inhibitory demands. Results showed that children do respond slower in the Reverse Sort task, and were consistent with the proposal that slowing down responding reduces inhibitory demands.