Observers Efficiently Extract the Minimal and Maximal Element in Perceptual Magnitude Sets: Evidence for a Bipartite Format

Darko Odic, Tyler Knowlton, Alexis Wellwood, Paul Pietroski, Jeffrey Lidz

Research output: Contribution to journalArticlepeer-review


The mind represents abstract magnitude information, including time, space, and number, but in what format is this information stored? We show support for the bipartite format of perceptual magnitudes, in which the measured value on a dimension is scaled to the dynamic range of the input, leading to a privileged status for values at the lowest and highest end of the range. In six experiments with college undergraduates, we show that observers are faster and more accurate to find the endpoints (i.e., the minimum and maximum) than any of the inner values, even as the number of items increases beyond visual short-term memory limits. Our results show that length, size, and number are represented in a dynamic format that allows for comparison-free sorting, with endpoints represented with an immediately accessible status, consistent with the bipartite model of perceptual magnitudes. We discuss the implications for theories of visual search and ensemble perception.

Original languageAmerican English
JournalPsychological Science
StateAccepted/In press - 2024

ASJC Scopus subject areas

  • General Psychology


  • computational theory of mind
  • open data
  • open materials
  • perceptual magnitudes
  • preregistered
  • representational format
  • working memory limits

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