Evidence for conceptual combination in the left anterior temporal lobe.

Conceptual combination allows for the construction of an infinite number of complex ideas from a finite base. The anterior temporal lobes appear to be important for the process of conceptual combination. In a previous study (Baron et al., 2010) we showed that the neural representation of complex concepts (e.g., young man) in the left anterior temporal lobe is additive. Specifically, in that region, the representation of a complex concept can be predicted by the superimposition of the voxel-wise neural representations of its constituent concepts (e.g., young+man). However, this finding could be the result of phonological similarity or the simple co-activation of constituent concepts. Here we use concepts that are only related semantically: boy, girl, woman, man, female, male, child, and adult. The neural representation for each concept was evoked through a visual categorization task. Subsequent brain maps were then analyzed using a searchlight analysis meant to show areas of the cortex where multiplicative (as well as additive) conceptual combination occurred (e.g., areas in which activations for boy correlated with the product of the activations for male and child). Across all participants, the left anterior temporal lobe showed such an effect.