Two separate processes affect the development of the mental number line Academic Article uri icon


  • Two processes are apparently involved when adults compare magnitudes. One is an analog comparison process, which produces the distance effect—a decrease in reaction time (RT) the larger the difference between two compared magnitudes (Moyer and Landauer, 1967). The other is the activation of end stimuli (ie, objects learned to be representing the smallest or the largest magnitudes in the set), which results in the end effect—faster processing of pairs that include the end stimuli of a set (Banks, 1977). Leth-Steensen and Marley (2000) proposed a formal model that shows how the two processes can account for comparisons RTs involving ordinal magnitudes.Natural numbers are symbolic representations of magnitudes which, at least in adults, are apparently represented along a mental number line (eg, Dehaene, 1997; Gallistel and Gelman, 2000). Automatic processing allows a direct …

publication date

  • January 1, 2013