The neural basis of the paired-object affordance effect
Résumé
Recent behavioral studies indicate that right-handed individuals make faster action decisions on object pairs that appear in standard co-location for right-handed actions in comparison to object pairs that appear in a mirror location. In this fMRI study, we aimed to investigate the neural correlates of visual processing of thematic relations between co-acting objects (frying pan and spatula), depending of their co-location for right-handed actions. Fourteen right-handed participants made decisions about thematically related and unrelated object pairs. Pairs were either positioned in a standard location for a right-handed action (with the active object - spatula in the right visual hemifield, and the passive object - frying pan in the left visual hemifield), or in the reverse location. Behavioral results showed a benefit of positioning thematically related pairs in standard co-location when an action decision was made (deciding if the two objects are usually used together), but not when a more general contextual decision was made (deciding if the two object are typically found in the kitchen). Neuroimaging results showed that the left lateral occipital complex was more activated for standard than reverse locations. Our results provide novel evidence of close interrelations between thematic and action processing in the posterior semantic system.