This dataset contains observer data and stimulus information for the below publication. Refer to this manuscript for more details. Laysa Hedjar, Matteo Toscani, and Karl R. Gegenfurtner, "Perception of saturation in natural objects," Journal of the Optical Society of American A 40(3), A190-A198 (2023), doi:10.1364/JOSAA.476874. Participant data is available in two files: fruit_pt_data.csv and blob_pt_data.csv fruit_pt_data.csv: fruit name: name of fruit pair object or swatch: whether the stimulus pair were whole objects or 8x8 swatches participant ID: given participant identification number proportion positive: proportion of trials in which participant chose the positive stimulus as more saturated (out of 10 total trials per stimulus pair) blob_pt_data.csv: blob hue (radians - LAB): hue in radians of the blob pair, as defined in LAB-LCH color space object or swatch: whether the stimulus pair were whole objects or 8x8 swatches matched or unmatched: whether the stimulus pair were matched in terms of blob ID (refers to spatial configuration) positive stimulus ID: identification number of the positive LC-slope stimulus (refers to spatial configuration) negative stimulus ID: identification number of the negative LC-slope stimulus (refers to spatial configuration) note that the above two IDs should be identical if the stimulus is a 'matched' pair participant ID: given participant identification number proportion positive: proportion of trials in which participant chose the positive stimulus as more saturated (out of 5 total trials per stimulus pair) Stimuli pngs are in the zip file stimuli.zip. Pngs are not gamma-corrected. Blob and fruit stimulus sets are separated by folder; object and swatch stimulus sets are also separated by folder. Fruit pngs are labeled: fruit_[object/swatch]_[fruitName]-[negative/positive].png For blob pngs, six possible spatial configurations for each hue were used. An ID was given for each configuration. Blob pngs are labeled: blob_[object/swatch]_hue[hueInRadians]_ID[1-6]-[negative/positive].png Statistics of the stimulus images are presented in the files fruit_stats_objects.csv, fruit_stats_swatches.csv, blob_stats_objects.csv, and blob_stats_swatches.csv. Each column represents a different stimulus image. Each row represents a different statistic taken across the distribution of pixels. Calculations were made in CIELAB-LCH color space ('white point' defined as white of monitor: CIE1931 xyY 0.3328, 0.3343, 142.35).