title: Stimulus luminance and the spatial acuity of domestic fowl (Gallus g. domesticus).
abstract: The luminance dependence of spatial acuity in domestic fowl was measured directly over stimulus luminances ranging from 0.06 to 57.35 cd m(-2). At the highest luminance, acuity was around 6.5 c deg(-1), in agreement with previous studies in this species. As stimulus luminance decreased, acuity fell with increasing rate to 3.2 c deg(-1) at 0.06 cd m(-2), following the same shape as acuity functions for other mammalian and avian species. These findings suggest that the rod-cone transition for domestic fowl is between 0.45 and 1.79 cd m(-2). Over the photopic range from 1.79 to 57.35 cd m(-2) the change of acuity for fowl was 1%, compared with 32% for humans. For domestic fowl, the Rovamo-Barten MTF model of contrast sensitivity accounted for the behaviour of acuity as a function of luminance down to mesopic levels.
authors.affiliation: The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK. ngover@rvc.ac.uk
authors.forename: Nick
authors.initials: N
authors.lastname: Gover
authors.forename: John R
authors.initials: JR
authors.lastname: Jarvis
authors.forename: Siobhan M
authors.initials: SM
authors.lastname: Abeyesinghe
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Wathes
mesh_terms: D000818:Animals; D002645:Chickens / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008029:Lighting; D010775:Photic Stimulation / Q000379:methods; D013028:Space Perception / Q000502:physiology*; D013045:Species Specificity; D014792:Visual Acuity / Q000502:physiology*