@article{SixtusLindemannFischer2018,
  author    = {Sixtus, Elena and Lindemann, Oliver and Fischer, Martin H.},
  title     = {Stimulating numbers},
  series = {Psychological research : an international journal of perception, attention, memory, and action},
  volume    = {84},
  journal   = {Psychological research : an international journal of perception, attention, memory, and action},
  number    = {1},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0340-0727},
  doi       = {10.1007/s00426-018-0982-y},
  pages     = {152 -- 167},
  year      = {2018},
  abstract  = {Finger counting is one of the first steps in the development of mature number concepts. With a one-to-one correspondence of fingers to numbers in Western finger counting, fingers hold two numerical meanings: one is based on the number of fingers raised and the second is based on their ordinal position within the habitual finger counting sequence. This study investigated how these two numerical meanings of fingers are intertwined with numerical cognition in adults. Participants received tactile stimulation on their fingertips of one hand and named either the number of fingers stimulated (2, 3, or 4 fingers; Experiment 1) or the number of stimulations on one fingertip (2, 3, or 4 stimulations; Experiment 2). Responses were faster and more accurate when the set of stimulated fingers corresponded to finger counting habits (Experiment 1) and when the number of stimulations matched the ordinal position of the stimulated finger (Experiment 2). These results show that tactile numerosity perception is affected by individual finger counting habits and that those habits give numerical meaning to single fingers.},
  language  = {en}
}
@article{SixtusLonnemannFischeretal.2019,
  author    = {Sixtus, Elena and Lonnemann, Jan and Fischer, Martin H. and Werner, Karsten},
  title     = {Mental Number Representations in 2D Space},
  series = {Frontiers in Psychology},
  volume    = {10},
  journal   = {Frontiers in Psychology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-1078},
  doi       = {10.3389/fpsyg.2019.00172},
  pages     = {11},
  year      = {2019},
  abstract  = {There is evidence both for mental number representations along a horizontal mental number line with larger numbers to the right of smaller numbers (for Western cultures) and a physically grounded, vertical representation where "more is up." Few studies have compared effects in the horizontal and vertical dimension and none so far have combined both dimensions within a single paradigm where numerical magnitude was task-irrelevant and none of the dimensions was primed by a response dimension. We now investigated number representations over both dimensions, building on findings that mental representations of numbers and space co-activate each other. In a Go/No-go experiment, participants were auditorily primed with a relatively small or large number and then visually presented with quasi-randomly distributed distractor symbols and one Arabic target number (in Go trials only). Participants pressed a central button whenever they detected the target number and elsewise refrained from responding. Responses were not more efficient when small numbers were presented to the left and large numbers to the right. However, results indicated that large numbers were associated with upper space more strongly than small numbers. This suggests that in two-dimensional space when no response dimension is given, numbers are conceptually associated with vertical, but not horizontal space.},
  language  = {en}
}
@article{SixtusLindnerLohseetal.2023,
  author    = {Sixtus, Elena and Lindner, Nadja and Lohse, Karoline and Lonnemann, Jan},
  title     = {Investigating the influence of body movements on children's mental arithmetic performance},
  series = {Acta psychologica : international journal of psychonomics},
  volume    = {239},
  journal   = {Acta psychologica : international journal of psychonomics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0001-6918},
  doi       = {10.1016/j.actpsy.2023.104003},
  pages     = {7},
  year      = {2023},
  abstract  = {Several lines of research have demonstrated spatial-numerical associations in both adults and children, which are thought to be based on a spatial representation of numerical information in the form of a mental number line. The acquisition of increasingly precise mental number line representations is assumed to support arithmetic learning in children. It is further suggested that sensorimotor experiences shape the development of number concepts and arithmetic learning, and that mental arithmetic can be characterized as "motion along a path" and might constitute shifts in attention along the mental number line. The present study investigated whether movements in physical space influence mental arithmetic in primary school children, and whether the expected effect depends on concurrency of body movements and mental arithmetic. After turning their body towards the left or right, 48 children aged 8 to 10 years solved simple subtraction and addition problems. Meanwhile, they either walked or stood still and looked towards the respective direction. We report a congruency effect between body orientation and operation type, i.e., higher performance for the combinations leftward orientation and subtraction and rightward orientation and addition. We found no significant difference between walking and looking conditions. The present results suggest that mental arithmetic in children is influenced by preceding sensorimotor cues and not necessarily by concurrent body movements.},
  language  = {en}
}
@article{SixtusFischerLindemann2017,
  author    = {Sixtus, Elena and Fischer, Martin H. and Lindemann, Oliver},
  title     = {Finger posing primes number comprehension},
  series = {Cognitive processing : international quarterly of cognitive science},
  volume    = {18},
  journal   = {Cognitive processing : international quarterly of cognitive science},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1612-4782},
  doi       = {10.1007/s10339-017-0804-y},
  pages     = {237 -- 248},
  year      = {2017},
  abstract  = {Canonical finger postures, as used in counting, activate number knowledge, but the exact mechanism for this priming effect is unclear. Here we dissociated effects of visual versus motor priming of number concepts. In Experiment 1, participants were exposed either to pictures of canonical finger postures (visual priming) or actively produced the same finger postures (motor priming) and then used foot responses to rapidly classify auditory numbers (targets) as smaller or larger than 5. Classification times revealed that manually adopted but not visually perceived postures primed magnitude classifications. Experiment 2 obtained motor priming of number processing through finger postures also with vocal responses. Priming only occurred through canonical and not through non-canonical finger postures. Together, these results provide clear evidence for motor priming of number knowledge. Relative contributions of vision and action for embodied numerical cognition and the importance of canonicity of postures are discussed.},
  language  = {en}
}
@article{SixtusFischer2015,
  author    = {Sixtus, Elena and Fischer, Martin H.},
  title     = {Eine kognitionswissenschaftliche Betrachtung der Konzepte "Raum" und "Zahl"},
  series = {Raum und Zahl im Fokus der Wissenschaften : eine multidisziplin{\"a}re Vorlesungsreihe},
  journal   = {Raum und Zahl im Fokus der Wissenschaften : eine multidisziplin{\"a}re Vorlesungsreihe},
  publisher = {Trafo},
  address   = {Berlin},
  isbn      = {978-3-86464-082-7},
  pages     = {35 -- 62},
  year      = {2015},
  language  = {de}
}