How the brain builds a word meaning

Liuba Papeo

Centre national de la recherche scientifique (CNRS)

Events and entities are fundamental components of the human conceptual framework, as much as verbs and nouns are fundamental to the human communication system. Verbs carry information about events. Thus, studying how people process verbs provides a window into the human conceptual architecture. Two independent lines of research have consistently associated the conceptual processing of verbs with neural activity in the left posterior lateral temporal cortex and in the motor precentral cortex, respectively. These parts of the cortex show different response properties to verbs. Current research focus on one region or another, with scant consideration to the relationship between the two sets of results, leads to dramatically different theories of conceptual representations. After delineating the verb-related activity in the temporal and precentral cortex, I will introduce research that investigates their functional relevance for verb processing, by measuring the behavioral consequences of their “perturbation” (through transcranial magnetic stimulation – TMS, and in brain-damaged patients). I will then present the results of a study that, combining neuroimaging data and different TMS protocols, addresses the relationship between the two parts of the brain. Finally, I will discuss what the interplay between these two regions tells us about the general organization of the supposedly larger network that supports conceptual knowledge.