Magnitudes In The Coding Of Visual Multitudes: Evidence From Adaptation

Four adaptation experiments examine the relationship between texture density and perceived number. In Experiment 1 [Huk, A. C., & Durgin, F. H. (1996). Concordance of numerosity comparison and numerosity estimation: Evidence from adaptation [abstract]. Investigative Ophthalmology & Visual Science, 37(3), 1341], magnitude estimation (5–1152 dots) with and without adaptation to dense textures was less affected by adaptation at low number (up to about 20, where estimation was fairly linear), but were logarithmically scaled and proportionally affected by adaptation for numbers of 40 and more. Experiments 2 through 4 show that texture density adaptation to composite texture units (sheep) seems to be based on feature numerosity/density (legs), although unitization is not utterly unsuccessful. Adaptation to dense texture does affect magnitude estimation of number, but perceived number dissociates from effective density when it comes to adaptation. The perceptual unit applied to a multitude is tailored to the specific sensory magnitude being used for the estimation of number, and the scaling of number estimation can be aided by exposure to the subitizing range