Accessing the asymmetrical representations of causal relations and hierarchical relations in semantic memory

Recent studies of causal relations have reported faster verification if two words appear in ?cause?effect? order than if they appear in ?effect?cause? order. The current study investigated whether such differences are specific to causal relations or exist for other types of asymmetric relations, such as hierarchical relations. Participants were asked to decide whether two simultaneously presented words were causally related or hierarchically related, when the word pair was vertically aligned (Experiment 1) or horizontally aligned (Experiment 2). Both causal and hierarchical relationships were verified faster if ?cause?/?superordinate-level? appeared vertically above ?effect?/?subordinate-level? than the reverse. However, if word pairs were presented horizontally, only causal relationships were verified faster when cause preceded effect. People appear to represent the causal asymmetry based on temporal order when queried about causal relationships, whereas the representation of hierarchical asymmetry is based on spatial arrangement when queried about hierarchical relationships.