Feature selective adaptation of numerosity perception

Perceptual adaptation has been widely used to infer the existence of numerosity detectors, enabling animals to quickly estimate the number of objects in a scene. Here we investigated, in humans, whether numerosity adaptation is influenced by stimuli features changes as previous research suggested that adaptation is more pronounced when adapting and test stimuli share the same color. We tested whether such adaptation reduction is due to a novelty effect (due to changing stimulus features) or changes of stimuli identity. Numerosity adaptation was measured for stimuli matched or unmatched for low-level (color, luminance, shape, motion) or high-level (letters' identity, face emotions) features. Robust numerosity adaptation occurred in all conditions but it was reduced when adapting and test stimuli differed for color, luminance, and shape. However, no reduction was observed between moving and still stimuli, a readable change that did not affect item’s identity. Similarly, changes in letters..., , , # Feature selective adaptation of numerosity perception

[https://doi.org/10.5061/dryad.280gb5mz4](https://doi.org/10.5061/dryad.280gb5mz4)

We investigated, in humans, whether numerosity adaptation is influenced by stimuli features changes as previous research suggested that adaptation is more pronounced when adapting and test stimuli share the same color. Numerosity adaptation was measured for stimuli matched or unmatched for low-level (Experiment 1: color, Experiment 2: luminance, Experiment 3: shape, Experiment 4: motion) or high-level (Experiment 5: letters' identity, Experiment 6:face emotions) features. Across all experiments, a total of 56 participants took part in the study (mean age: 25.2, standard deviation: 3.9, 37 females). Each participant performed one or more of six different experiments which differed in the type of feature characterizing the arrays of visual stimuli. Each experiment aimed at investigating whether and to what extent the congruency between the adapting ...