It’s not what you’re naming, it’s how you name it: Process-driven neural recruitment for objects in inferior temporal cortex.

How conceptual representations are instantiated in the brain remains a key issue in cognitive neuroscience. Recent work carried out in primates (Murray and Bussey, 1999) and humans (Tyler et al, JOCN in press) suggests that objects are processed within a hierarchically-organised feature-based distributed system in ventral temporal cortex, extending from posterior fusiform to anteromedial regions. Neurons within anteromedial temporal cortices represent complex conjunctions of features which enable fine-grained differentiation (Simmons & Barsalou, 2003). On this account, tasks requiring fine-grained discrimination among objects should engage these anterior regions, relative to those requiring more coarse-grained analysis. Since living things generally have more shared, and fewer distinctive, visual features than do artefacts, and therefore require more fine-grained discrimination to differentiate between objects (Tyler & Moss, 2001), we predict that living things will involve anteromedial regions more than artefacts in tasks requiring fine-grained discrimination. We tested this prediction in an efMRI study in which subjects named coloured pictures of common objects (animals, fruits, vehicles, tools), at two levels of specificity (basic and domain level). Basic naming [eg cat, axe] requires more fine grained differentiation than domain naming [eg living thing].which relies on shared properties. Consistent with our predictions, basic naming generated significantly greater activation in anteromedial temporal cortex for animals and fruits relative to vehicles and tools. There was no consistent evidence that this region is recruited during domain naming. These results suggest that neural regions involved in object processing reflect the nature of processing demands imposed by the task rather than stimulus-specific activations.