Where and when Do Objects Become Scenes?

Scenes can be understood with extraordinary speed and facility, not merely as an inventory of individual objects but in the coding of the relations among them. These relations, which can be readily described by prepositions or gerunds (e.g., a hand holding a pen), allows the explicit representation of complex structures. Where in the brain are inter-object relations specified? In a series of fMRI experiments, we show that pairs of objects shown as interacting elicit greater activity in LOC than when the objects are depicted side-by-side (e.g., a hand beside a pen). Other visual areas, PPA, IPS, and DLPFC, did not show this sensitivity to scene relations, rendering it unlikely that the relations were computed in these regions. Using EEG and TMS, we further show that LOC's sensitivity to object interactions arises around 170ms post stimulus onset and that disruption of normal LOC activity—but not IPS activity—is detrimental to the behavioral sensitivity of inter-object relations. Insofar as LOC is the earliest cortical region where shape is distinguished from texture, our results provide strong evidence that scene-like relations are achieved simultaneously with the perception of object shape and not inferred at some stage following object identification.