Spatial contrast sensitivity of the tree shrew

• Published in: Vision research (Oxford) Vol. 24; no. 9; pp. 1037 - 1042
• Main Authors: Petry, Heywood M., Fox, Robert, Casagrande, Vivien A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1984; Elsevier Science
• Subjects: Animal psychophysics; Animals; Biological and medical sciences; Contrast sensitivity; Discrimination (Psychology) - physiology; Eye and associated structures. Visual pathways and centers. Vision; Female; Form Perception - physiology; Fundamental and applied biological sciences. Psychology; Grating acuity; Male; Pattern Recognition, Visual - physiology; Psychophysics; Refractive Errors - physiopathology; Sensory Thresholds - physiology; Spatial vision; Tree shrew; Tupaia belangeri; Tupaiidae - physiology; Vertebrates: nervous system and sense organs; Visual Acuity; Tree shrew; Animal psychophysics; Grating acuity; Contrast sensitivity; Spatial vision; Space; Vertebrata; Mammalia; Discrimination; Visual field; Vision; Contrast; Insectivora
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/0042-6989(84)90080-4

Spatial contrast sensitivity functions (CSFs) were measured for 3 tree shrews. Our two- alternative forced-choice discrimination paradigm required the animals to discriminate a vertical sine-wave luminance grating from a homogenous field of the same size (16°) and mean luminance (35 cd/m 2). Spatial frequencies tested ranged from 0.1 to 2.0c/deg and grating contrast was varied trial-by-trial using a modified staircase technique. Small between-subject variations in the shape of the CSFs appeared to be correlated with our estimates of refractive error for each animal. In general, the CSFs were of the typical band-pass type with peak sensitivity occurring at approximately 0.7c/deg. Estimates of grating acuity derived from the CSFs ranged from 1.2 to 2.4c/deg and are within the limitations set by the eye size and retinal anatomy of the tree shrew.