FMRI activation differences between 11-year-old good and poor spellers' access in working memory to temporary and long-term orthographic representations

Abstract

Two fMRI task contrasts identified BOLD activation differences between good and poor 11-year-old spellers. On the first contrast comparing judgments about letters in unfamiliar orthographic representations (pseudowords) no longer displayed versus displayed (at the time of judgement), good and poor spellers differed in left posterior cingulate and calcarine and bilateral precuneus; fMRI activation correlated with real-word reading rate in good spellers and with composition in poor spellers. On the second contrast comparing judgments about whether both items in a pair pronounced the same were both correctly spelled real words and whether both letter strings matched exactly, good spellers activated more than poor writers in the left precentral gyrus, postcentral gyrus, and inferior frontral gyrus, and right superior frontal gyrus, but poor writers activated more than good writers in left primary motor and superior and middle frontal, and word form, and right cuneus and middle frontal regions; fMRI activation in 7 regions correlated with spelling achievement. Results have implications for how both temporary orthographic representations of unfamiliar written words and long-term, precise representations of familiar, learned words contribute to middle-childhood spelling acquisition.