Context affects the numerical semantic congruity effect in rhesus monkeys (Macaca mulatta).


Journal Article

Do monkeys anchor their numerical judgments based on the context in which their choices are presented? We addressed this question by varying the numerical range across sessions while macaque monkeys made ordinal judgments. Monkeys were trained to make a conditional discrimination whereby they were reinforced for ordering arrays of dots in ascending or descending numerical order, dependent on a color cue. Monkeys were tested using two ranges of numerosities that converged on a single pair. Similar to the findings of Cantlon and Brannon (2005), we found a semantic congruity effect whereby decision time was systematically influenced by the congruity between the cue (ascending or descending) and the relative Numerical Magnitude of the stimuli within each range. Furthermore, monkeys showed a context effect, such that decision time for a given pair was dependent on whether it was a relatively small or large set of values compared to the other values presented in that session. This finding suggests that, similar to humans, the semantic congruity effect observed in monkeys is anchored by the context. Thus our data provide further evidence for the existence of a shared numerical comparison process in monkeys and humans.

Full Text

Cited Authors

  • Jones, SM; Cantlon, JF; Merritt, DJ; Brannon, EM

Published Date

  • February 2010

Published In

Volume / Issue

  • 83 / 2

Start / End Page

  • 191 - 196

PubMed ID

  • 20015467

Pubmed Central ID

  • 20015467

Electronic International Standard Serial Number (EISSN)

  • 1872-8308

International Standard Serial Number (ISSN)

  • 0376-6357

Digital Object Identifier (DOI)

  • 10.1016/j.beproc.2009.12.009


  • eng