Neural and linguistic differences explain priming and interference during naming

Abstract

When naming an object, humans are faster to produce the name ("cat") if immediately having named a related object ("dog") but paradoxically slower to name the same object ("cat") if there are intervening speech acts (Wei and Schnur 2019). This dependence of behavior on prior experience is ubiquitous in other domains, often termed "priming" (if behavior is speeded) or "interference" (if behavior is slower). However, it is unknown the changes in the language system (conceptual, lexical, and/or connections between representations) and corresponding brain mechanisms which create these paradoxical effects on the same speech act. Using fMRI during simple picture naming, we observed distinct brain regions and different connections associated with priming and interference. Greater priming was associated with increased activation in the ventral occipitotemporal cortex, while greater interference was associated with decreased functional connectivity between the left posterior temporal and angular gyri. To provide neural evidence of where in the language system priming and interference in naming occur, we assayed the response of different brain areas to conceptual or lexical aspects of speech. The brain and language systems adapt to prior naming experience by modulating conceptual representations during priming, but modulating conceptual, lexical and the mapping between representations during interference.