The 'reading' brain: Meta-analytic insight into functional activation during reading in adults

Abstract

Literacy provides the key to social contacts, education, and employment, and significantly influences well-being and mental health. Summarizing 163 studies, the present coordinate-based meta-analysis confirms the importance of classical left-hemispheric language regions and the cerebellum across reading tasks. We found high processing specificity for letter, word, sentence, and text reading exclusively in left-hemispheric areas. Subregions within the left inferior frontal gyrus showed differential engagement for word and pseudoword reading, while subregions within the left temporo-occipital cortex showed differential engagement for words and sentences. The direct comparison of overt and covert reading revealed higher activation likelihood in auditory and motor regions during the first, and more consistent reliance on multiple demand regions during the latter. Last, silent word and pseudoword reading (explicit reading) yielded more consistent activation in left orbito-frontal, cerebellar and temporal cortices when compared to lexical decisions (implicit reading). Lexical decisions, in contrast, showed more consistent bilateral recruitment of inferior frontal and insular regions. The present meta-analysis significantly extends our understanding of the neural architecture underlying reading, corroborates findings from neurostimulation studies and can provide valuable neural insight into reading models.

Keywords: Language; Meta-analysis; Pseudowords; Reading; Words; fMRI.