title: Subitizing reflects visuo-spatial object individuation capacity.
abstract: Subitizing is the immediate apprehension of the exact number of items in small sets. Despite more than a 100years of research around this phenomenon, its nature and origin are still unknown. One view posits that it reflects a number estimation process common for small and large sets, which precision decreases as the number of items increases, according to Weber's law. Another view proposes that it reflects a non-numerical mechanism of visual indexing of multiple objects in parallel that is limited in capacity. In a previous research we have gathered evidence against the Weberian estimation hypothesis. Here we provide first direct evidence for the alternative object indexing hypothesis, and show that subitizing reflects a domain general mechanism shared with other tasks that require multiple object individuation.
authors.affiliation: Center for Mind/Brain Sciences, University of Trento, Italy. manuela.piazza@gmail.com
authors.forename: Manuela
authors.initials: M
authors.lastname: Piazza
authors.forename: Antonia
authors.initials: A
authors.lastname: Fumarola
authors.forename: Alessandro
authors.initials: A
authors.lastname: Chinello
authors.forename: David
authors.initials: D
authors.lastname: Melcher
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D013028:Space Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*