Measurement of contrast thresholds of chimpanzees using a Parameter Estimation by Sequential Testing (PEST) procedure(Summary of Awarded Presentations at the 24th Annual Meeting)

抄録

The detectability of luminance-modulated grating patches was determined for 4 adult chimpanzees. The behavioral experiment with the chimpanzees used a Parameter Estimation by Sequential Testing (PEST) procedure. The first experiment evaluated the consistency and reliability of the thresholds estimated with the PEST procedure in comparison to those collected with the method of constant stimuli. The chimpanzees displayed very small between-session variances of threshold values to detect a 0.5c/deg horizontal Gabor-type patch. The threshold values were also well-matched to those estimated with the method of constant stimuli. In the second experiment, contrast sensitivity functions were obtained over the range of 0.5-8.0c/deg. The contrast sensitivity was similar to that of humans, showing bandpass shape functions with both low and high frequency attenuation. These results suggest that humans and chimpanzees share the same physiological mechanisms which underlie spatial vision.