The brain bases of reading late learned words: Evidence from functional MRI

Abstract

Age of acquisition (AoA) effects for reading have been documented in the literature. Recent studies have suggested that more effortful phonological retrieval is involved in picture naming for late learned words. Here we use functional magnetic resonance imaging to determine the neuroanatomical correlates of AoA effects in reading, and to explore whether AoA effects in the brain modulate activity in areas devoted to phonological processing. Participants were asked to covertly name blocks of early and late learned words while being scanned with functional MRI. Results revealed a relative increase in neural activity for late learned words in a set of brain areas involved in auditory-phonological processing (the planum temporale of the posterior-superior left temporal lobe) and articulatory motor planning (BA 44, putamen, and globus pallidus). These findings support the view that late learned words involve more effortful phonological retrieval, but in addition point to a second locus of the AoA effect in the articulatory component of the reading system.