@article{WiemersBekkeringLindemann2014,
  author    = {Wiemers, Michael and Bekkering, Harold and Lindemann, Oliver},
  title     = {Spatial interferences in mental arithmetic: Evidence from the motion-arithmetic compatibility effect},
  series = {The quarterly journal of experimental psychology},
  volume    = {67},
  journal   = {The quarterly journal of experimental psychology},
  number    = {8},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {1747-0218},
  doi       = {10.1080/17470218.2014.889180},
  pages     = {1557 -- 1570},
  year      = {2014},
  abstract  = {Recent research on spatial number representations suggests that the number space is not necessarily horizontally organized and might also be affected by acquired associations between magnitude and sensory experiences in vertical space. Evidence for this claim is, however, controversial. The present study now aims to compare vertical and horizontal spatial associations in mental arithmetic. In Experiment 1, participants solved addition and subtraction problems and indicated the result verbally while moving their outstretched right arm continuously left-, right-, up-, or downwards. The analysis of the problem-solving performances revealed a motion-arithmetic compatibility effect for spatial actions along both the horizontal and the vertical axes. Performances in additions was impaired while making downward compared to upward movements as well as when moving left compared to right and vice versa in subtractions. In Experiment 2, instead of being instructed to perform active body movements, participants calculated while the problems moved in one of the four relative directions on the screen. For visual motions, only the motion-arithmetic compatibility effect for the vertical dimension could be replicated. Taken together, our findings provide first evidence for an impact of spatial processing on mental arithmetic. Moreover, the stronger effect of the vertical dimension supports the idea that mental calculations operate on representations of numerical magnitude that are grounded in a vertically organized mental number space.},
  language  = {en}
}
@article{GianelliRanziniMarzocchietal.2012,
  author    = {Gianelli, Claudia and Ranzini, Mariagrazia and Marzocchi, Michele and Micheli, Leticia Rettore and Borghi, Anna M.},
  title     = {Influence of numerical magnitudes on the free choice of an object position},
  series = {Cognitive processing : international quarterly of cognitive science},
  volume    = {13},
  journal   = {Cognitive processing : international quarterly of cognitive science},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1612-4782},
  doi       = {10.1007/s10339-012-0483-7},
  pages     = {S185 -- S188},
  year      = {2012},
  abstract  = {The link between numerical magnitude and mechanisms of spatial orienting has been underlined in an increasing number of studies. Similarly, the relationship between numerical magnitude and grasping actions has started to be investigated. The present study focuses on the influence of numerical magnitude processing in the free choice of the position of an object. Participants were presented with a digit (1-9 without 5) and were required to decide whether it was smaller or larger than 5. Then, they had to grasp a small cube and change its position before vocally responding "higher" or "lower". Results showed that in the initial phase of the grasp movement, the grip aperture was modulated by the numerical magnitude. Moreover, participants shifted the position of the cube more leftward with smaller digits compared with larger ones, and they tended to position the object closer to themselves with smaller digits compared with larger ones. These results extend the previous findings indicating that the processing of magnitude is tightly related to the mechanisms of spatial orienting that subserve action execution.},
  language  = {en}
}