Subitizing reflects visuo-spatial object individuation capacity

Manuela Piazza, Antonia Fumarola, Alessandro Chinello, David Melcher

Research output: Contribution to journalArticlepeer-review


Subitizing is the immediate apprehension of the exact number of items in small sets. Despite more than a 100. years 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.

Original languageEnglish (US)
Pages (from-to)147-153
Number of pages7
Issue number1
StatePublished - Oct 2011


  • Capacity limits
  • Individuation
  • Subitizing
  • Visuo-spatial attention
  • Visuo-spatial working memory

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Language and Linguistics
  • Developmental and Educational Psychology
  • Linguistics and Language
  • Cognitive Neuroscience


Dive into the research topics of 'Subitizing reflects visuo-spatial object individuation capacity'. Together they form a unique fingerprint.

Cite this