Proceedings of the Annual Meeting of the Cognitive Science Society

Human understanding of relations between objects depends onthe ability to code meaningful role bindings. Computationalmodels of relational reasoning have proposed that neuraloscillations provide a basic mechanism enabling workingmemory to code the bindings of objects into relational roles.We adapted a behavioral oscillation paradigm to investigatemoment-to-moment changes in representations of semanticroles. On each trial, a picture was presented showing an action(chasing) relating two animals, one animal playing an agentrole (chaser) and the other playing a patient role (chased). Afterthe picture disappeared, the inter-stimulus interval (ISI) wasvaried in densely-sampled increments followed by a verbalprobe indicating an animal in a role. Reaction time (RT) todecide the validity of the verbal probe was recorded. We foundthat RTs varied systematically with ISI in an oscillatoryfashion. A task that required memory for a relational roleevoked stronger theta- and alpha-band oscillations than did amemory task not involving relational roles. The behavioraloscillation patterns in the role-identification task revealed aphase shift between the two semantic roles in the alpha band.