Number-space associations without language: Evidence from preverbal human infants and non-human animal species

Psychon Bull Rev. 2017 Apr;24(2):352-369. doi: 10.3758/s13423-016-1126-2.


It is well known that humans describe and think of numbers as being represented in a spatial configuration, known as the 'mental number line'. The orientation of this representation appears to depend on the direction of writing and reading habits present in a given culture (e.g., left-to-right oriented in Western cultures), which makes this factor an ideal candidate to account for the origins of the spatial representation of numbers. However, a growing number of studies have demonstrated that non-verbal subjects (preverbal infants and non-human animals) spontaneously associate numbers and space. In this review, we discuss evidence showing that pre-verbal infants and non-human animals associate small numerical magnitudes with short spatial extents and left-sided space, and large numerical magnitudes with long spatial extents and right-sided space. Together this evidence supports the idea that a more biologically oriented view can account for the origins of the 'mental number line'. In this paper, we discuss this alternative view and elaborate on how culture can shape a core, fundamental, number-space association.

Keywords: Infants; Mental number line; Non-human animals; Number; Space-number association.

Publication types

  • Review

MeSH terms

  • Animals
  • Association Learning*
  • Concept Formation
  • Cues
  • Discrimination Learning
  • Female
  • Humans
  • Language Development*
  • Male
  • Mathematics*
  • Optical Illusions
  • Orientation*
  • Psychology, Child*
  • Size Perception*
  • Spatial Learning*
  • Species Specificity*