Displacement of the egocentric visual midline in altitudinal postchiasmatic scotomata

Neuropsychologia. 1993 Mar;31(3):261-5. doi: 10.1016/0028-3932(93)90090-m.


Vertical and horizontal bar bisection was assessed in six patients with homonymous altitudinal scotomata, four of whom had additional hemianopic scotomas. Analysis of performance showed a small but significant deviation of the bisection midline ("egocentric midline") to the upper field in four patients with blindness of the upper hemifield and a more pronounced deviation to the inferior hemifield in two patients with lower altitudinal field defects. In addition, horizontal bar bisection showed a shift of the egocentric midline towards the scotoma in all four patients with left- or right-sided homonymous hemianopia. Hence, location of the scotoma predicted direction of the shift of the egocentric midline but not degree of shift.

MeSH terms

  • Adult
  • Aged
  • Female
  • Humans
  • Male
  • Middle Aged
  • Scotoma / physiopathology*
  • Visual Field Tests
  • Visual Fields / physiology*