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  • Michael J Arcaro
    Princeton University
  • Lore Thaler
    Unversity of Durham
  • Derek J Quinlan
    University of Western Ontario, Canada
  • Simona Monaco
    University of Trento, Italy
  • Sarah Khan
    University of Western Ontario, Canada
  • Kenneth F Valyear
  • Rainer Goebel
    Maastricht University, Netherlands
  • Gordon N Dutton
    Glasgow Caledonian University
  • Melvyn A Goodale
    University of Western Ontario, Canada
  • Sabine Kastner
    Princeton University
  • Jody C Culham
    University of Western Ontario, Canada

Patients with injury to early visual cortex or its inputs can display the Riddoch phenomenon: preserved awareness for moving but not stationary stimuli. We provide a detailed case report of a patient with the Riddoch phenomenon, MC. MC has extensive bilateral lesions to occipitotemporal cortex that include most early visual cortex and complete blindness in visual field perimetry testing with static targets. Nevertheless, she shows a remarkably robust preserved ability to perceive motion, enabling her to navigate through cluttered environments and perform actions like catching moving balls. Comparisons of MC's structural magnetic resonance imaging (MRI) data to a probabilistic atlas based on controls reveals that MC's lesions encompass the posterior, lateral, and ventral early visual cortex bilaterally (V1, V2, V3A/B, LO1/2, TO1/2, hV4 and VO1 in both hemispheres) as well as more extensive damage to right parietal (inferior parietal lobule) and left ventral occipitotemporal cortex (VO1, PHC1/2). She shows some sparing of anterior occipital cortex, which may account for her ability to see moving targets beyond ~15 degrees eccentricity during perimetry. Most strikingly, functional and structural MRI revealed robust and reliable spared functionality of the middle temporal motion complex (MT+) bilaterally. Moreover, consistent with her preserved ability to discriminate motion direction in psychophysical testing, MC also shows direction-selective adaptation in MT+. A variety of tests did not enable us to discern whether input to MT+ was driven by her spared anterior occipital cortex or subcortical inputs. Nevertheless, MC shows rich motion perception despite profoundly impaired static and form vision, combined with clear preservation of activation in MT+, thus supporting the role of MT+ in the Riddoch phenomenon.

Keywords

  • Riddoch phenomenon, Blindsight, Vision, Motion perception, fMRI, Middle temporal area (MT+)
Original languageEnglish
Pages (from-to)150-165
JournalNeuropsychologia
Volume128
Issue numberMay
Early online date9 May 2018
DOIs
Publication statusPublished - May 2019
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