Investigating the Relations between Object Affordance and Perception Using Behavioural and Brain Imaging Experiments

Previous research has shown facilitatory effects on attention and perception when object pairs are positioned for action compared to when they are not positioned for action. The present thesis aimed to better understand the mechanisms underlying this paired-object affordance effect. Chapters 2 and 3 showed that different but interacting parieto-frontal networks contribute to the effects of paired-object affordance in healthy participants. Chapters 4 and 5 explored the effects of paired-object affordance on visual extinction; the data showed that recovery from extinction was sensitive to the familiarity of the object pair and the completeness of the active object rather than the passive object within an interacting pair. Finally, the role of contextual information and task demands on the automatic perception of paired-object affordance effects was directly explored. The results indicate that only explicit but not implicit task demands (searching for an action vs. a colour pair, respectively) had facilitatory effects on performance and that semantic information in a scene also modulates the automatic perception of paired-object affordance. The findings provide novel behavioural and neuroimaging evidence that paired-object affordance is influenced by contextual information and task demands, with the active object (the tool) within a pair modulating the allocation of attention. To my parents, Norbert and Marianne, Without whom none of my journey would be possible