Neural substrates of sublexical processing for spelling

Brain Lang. 2017 Jan;164:118-128. doi: 10.1016/j.bandl.2016.10.001. Epub 2016 Nov 10.

Abstract

We used fMRI to examine the neural substrates of sublexical phoneme-grapheme conversion during spelling in a group of healthy young adults. Participants performed a writing-to-dictation task involving irregular words (e.g., choir), plausible nonwords (e.g., kroid), and a control task of drawing familiar geometric shapes (e.g., squares). Written production of both irregular words and nonwords engaged a left-hemisphere perisylvian network associated with reading/spelling and phonological processing skills. Effects of lexicality, manifested by increased activation during nonword relative to irregular word spelling, were noted in anterior perisylvian regions (posterior inferior frontal gyrus/operculum/precentral gyrus/insula), and in left ventral occipito-temporal cortex. In addition to enhanced neural responses within domain-specific components of the language network, the increased cognitive demands associated with spelling nonwords engaged domain-general frontoparietal cortical networks involved in selective attention and executive control. These results elucidate the neural substrates of sublexical processing during written language production and complement lesion-deficit correlation studies of phonological agraphia.

Keywords: Phonological agraphia; Phonological processing; Spelling; Sublexical processing; Writing; fMRI.

MeSH terms

  • Adult
  • Agraphia / physiopathology*
  • Agraphia / psychology
  • Brain Mapping
  • Cerebral Cortex / physiology*
  • Female
  • Functional Laterality
  • Humans
  • Language*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Occipital Lobe / physiology
  • Reading
  • Temporal Lobe / physiology
  • Writing
  • Young Adult