The contributions of the ventral and the dorsal visual streams to the automatic processing of action relations of familiar and unfamiliar object pairs

Abstract

Recent studies suggest that action relations between objects affect behavioral and neural responses to action- related object pairs. Existing evidence indicates the involvement of both visual streams in this process. However, uncertainty remains regarding the functional roles of the ventral and the dorsal visual streams, and their interac- tion in the perception of the action relations between objects. In particular, it is not clear whether the involvement of either stream is dependent on object recognition. The present study aims to dissociate the effect of object fa- miliarity and automatic extraction of action relations by presenting familiar and novel object pairs, which either indicate action relations or not, in a context where the objects and their identification were task-irrelevant. The present study examines the possibility that the activation of the ventral visual stream is dependent on facilitated object recognition exclusively associated with familiar action relations, and tests whether the dorsal visual stream is recruited in the automatic processing of the action relations in paired-object scenarios. With a set of registered analyses, we revealed that both the dorsal and the ventral streams respond to action relations in paired-object scenarios, and the responses were not exclusive to familiar action relations. Registered dynamic causal modeling analysis revealed that the inherent inter-stream connectivity was inhibited by action relations, and further un- registered analysis revealed that there lacks significant inherent effective connectivity between the two streams. These results suggest that both visual streams respond to the experimental manipulation of action relations in paired-object scenarios, but contribute corresponding information to different computations, leading to dissocia- tions between the neural activities of the two streams. These results for the first time suggested a division of labor between the two visual streams in the automatic extraction of action relations in paired-object scenarios. Future study is needed to further explore the context-dependency of the collaboration of the two steams in processing action-related features in multiple-object scenarios.