Preserved mid-fusiform activation for visual words in a patient with a visual word recognition impairment

Neuropsychologia. 2014 Dec:65:113-24. doi: 10.1016/j.neuropsychologia.2014.10.012. Epub 2014 Oct 23.

Abstract

Previous functional imaging studies have highlighted the role of left ventral temporal cortex in processing written word forms. We explored activation and anatomical connectivity of this region in HE, a professional writer with alexia as a result of stroke affecting primarily white matter in the left inferior temporal lobe. We used a one-back visual recognition task and functional Magnetic Resonance Imaging to elicit automatic activation to various orthographic and non-orthographic stimuli. Surprisingly, HE showed cortical activation in the left mid-fusiform area during the presentation of words and word-like stimuli, suggesting that this region׳s role in processing visual words is intact despite his severely impaired reading. Diffusion Tensor Imaging data further suggest that HE shows an anatomical disconnection between the ventral temporal cortex and posterior middle temporal cortex. Together, these findings suggest that activation of word-specific regions of mid-fusiform gyrus is not sufficient to yield the conscious experience of reading in the absence of activity in downstream regions of the classical reading network.

Keywords: Connectivity; Diffusion tensor imaging (DTI); Disconnection syndrome; Functional MRI; Reading.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Diffusion Tensor Imaging
  • Dyslexia / pathology
  • Dyslexia / physiopathology*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Pattern Recognition, Visual / physiology*
  • Temporal Lobe / pathology
  • Temporal Lobe / physiopathology*