How words and space collide: Lexical and sublexical reading are reliant on separable reflexive and voluntary attention regions in hybrid tasks

Reading ability requires the coordination of many cognitive processes to be effective, including spatial attention. Recent functional magnetic resonance imaging (fMRI) evidence from Ekstrand et al. (2019) suggests that lexical reading is more associated with reflexive attentional orienting regions, whereas sublexical reading is more associated with voluntary attentional orienting regions. The current research sought to further examine the neuroanatomical relationship between reading and attention using a novel experimental design in fMRI. Participants performed four hybrid attentional orienting and reading-aloud tasks, where a reflexive or voluntary spatial cue preceded a lexical or sublexical target. Results indicated that lexical reading resulted in greater activation in the right temporoparietal junction, a reflexive orienting region. Sublexical reading resulted in greater activation in the left inferior frontal gyrus, left fusiform and inferior temporal gyrus, and right superior parietal lobule and intraparietal sulcus (voluntary orienting regions). Further, we found an interaction between reading and attention in the middle occipital gyrus. This study provides the most direct evidence to date that lexical and sublexical reading recruit differential attentional orienting regions during single-word reading in skilled readers. Implications for models of reading and attention, as well as for strategic remediation of their dysfunction, are discussed.