title: The Effect of Attentional Cueing and Spatial Uncertainty in Visual Field Testing.
abstract: OBJECTIVE
  To determine the effect of reducing spatial uncertainty by attentional cueing on contrast sensitivity at a range of spatial locations and with different stimulus sizes.
  
  
  METHODS
  Six observers underwent perimetric testing with the Humphrey Visual Field Analyzer (HFA) full threshold paradigm, and the output thresholds were compared to conditions where stimulus location was verbally cued to the observer. We varied the number of points cued, the eccentric and spatial location, and stimulus size (Goldmann size I, III and V). Subsequently, four observers underwent laboratory-based psychophysical testing on a custom computer program using Method of Constant Stimuli to determine the frequency-of-seeing (FOS) curves with similar variables.
  
  
  RESULTS
  We found that attentional cueing increased contrast sensitivity when measured using the HFA. We report a difference of approximately 2 dB with size I at peripheral and mid-peripheral testing locations. For size III, cueing had a greater effect for points presented in the periphery than in the mid-periphery. There was an exponential decay of the effect of cueing with increasing number of elements cued. Cueing a size V stimulus led to no change. FOS curves generated from laboratory-based psychophysical testing confirmed an increase in contrast detection sensitivity under the same conditions. We found that the FOS curve steepened when spatial uncertainty was reduced.
  
  
  CONCLUSIONS
  We show that attentional cueing increases contrast sensitivity when using a size I or size III test stimulus on the HFA when up to 8 points are cued but not when a size V stimulus is cued. We show that this cueing also alters the slope of the FOS curve. This suggests that at least 8 points should be used to minimise potential attentional factors that may affect measurement of contrast sensitivity in the visual field.
authors.affiliation: Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.|School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia.
authors.forename: Jack
authors.initials: J
authors.lastname: Phu
authors.affiliation: Centre for Eye Health, University of New South Wales, Kensington, New South Wales, Australia.|School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Kalloniatis
authors.affiliation: School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia.
authors.forename: Sieu K
authors.initials: SK
authors.lastname: Khuu
mesh_terms: D000328:Adult; D001288:Attention; D015350:Contrast Sensitivity / Q000502:physiology*; D003463:Cues; D004056:Differential Threshold / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011601:Psychophysics; D035501:Uncertainty; D058609:Visual Field Tests / Q000295:instrumentation; D014794:Visual Fields / Q000502:physiology*