Decomposing composition: The role of the left anterior temporal lobe within the combinatory network
The neuroscience of meaning composition faces a principled challenge: the integration of words into complex messages is achieved by a cascade of tightly correlated and possibly simultaneous computations. Thus, understanding this process requires ways to unpack the constituent processes. A consensus is beginning to emerge about the “combinatory network” of the brain: the composition of sentences appears to recruit posterior and anterior regions of the left temporal lobe, left inferior and ventromedial areas of frontal cortex and areas around the temporoparietal junction. Of the various network nodes, the computational role of the left anterior temporal lobe has been systematically characterized in a series of MEG studies designed to incrementally narrow down the space of possible interpretations as regards the function of this region. Here I review our current understanding of this node, which appears to contribute an early process of conceptual combination, as well as our more elusive understanding of the workings of the rest of the network.