The present work aims to contribute evidence to further our understanding of the human neurocognitive system by testing for interactions or sharing of resources among cognitive domains. To this end, several methods were employed and various variables were analysed. Following an action-centred and modular approach to the cognitive system in accordance with the ideomotor framework, I pursued the hypotheses that there are functional interactions among (some) cognitive domains and that hierarchical processing might be characteristic of multiple (if not all) domains.