@misc{LohseSixtusLonnemann2019,
  author    = {Lohse, Karoline and Sixtus, Elena and Lonnemann, Jan},
  title     = {Thinking about time and number},
  series = {Behavioral and brain sciences : an international journal of current research and theory with open peer commentary},
  volume    = {42},
  journal   = {Behavioral and brain sciences : an international journal of current research and theory with open peer commentary},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {0140-525X},
  doi       = {10.1017/S0140525X19000475},
  pages     = {2},
  year      = {2019},
  abstract  = {Based on the notion that time, space, and number are part of a generalized magnitude system, we assume that the dual-systems approach to temporal cognition also applies to numerical cognition. Referring to theoretical models of the development of numerical concepts, we propose that children's early skills in processing numbers can be described analogously to temporal updating and temporal reasoning.},
  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}
}
@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}
}
@inproceedings{SixtusLindemannFischer2014,
  author    = {Sixtus, Elena and Lindemann, Oliver and Fischer, Martin H.},
  title     = {The flexibility of finger-based magnitude representations},
  series = {Cognitive processing : international quarterly of cognitive science},
  volume    = {15},
  booktitle = {Cognitive processing : international quarterly of cognitive science},
  number    = {1},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1612-4782},
  pages     = {S68 -- S69},
  year      = {2014},
  language  = {en}
}
@misc{FischerSixtusGoebel2015,
  author    = {Fischer, Martin H. and Sixtus, Elena and G{\"o}bel, Silke M.},
  title     = {Commentary},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {420},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-406260},
  pages     = {3},
  year      = {2015},
  abstract  = {kein Abstract vorhanden},
  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}
}
@misc{SixtusLonnemannFischeretal.2019,
  author    = {Sixtus, Elena and Lonnemann, Jan and Fischer, Martin H. and Werner, Karsten},
  title     = {Mental Number Representations in 2D Space},
  series = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Humanwissenschaftliche Reihe},
  number    = {538},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-42496},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-424960},
  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}
}
@unpublished{FischerSixtusGoebel2015,
  author    = {Fischer, Martin H. and Sixtus, Elena and G{\"o}bel, Silke M.},
  title     = {Commentary: A pointer about grasping numbers},
  series = {Frontiers in psychology},
  volume    = {6},
  journal   = {Frontiers in psychology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  doi       = {10.3389/fpsyg.2015.00227},
  pages     = {3},
  year      = {2015},
  language  = {en}
}
@book{GuentherPetscheFischeretal.2015,
  author    = {G{\"u}nther, Oliver and Petsche, Hans-Joachim and Fischer, Martin H. and Franz, Norbert P. and Steup, Martin and Sixtus, Elena and Heimann, Heinz-Dieter and Pr{\"o}ve, Ralf},
  title     = {Raum und Zahl im Fokus der Wissenschaften},
  series = {Studieren ++ : Konzepte, Perspektiven, Kompetenzen ; 1},
  journal   = {Studieren ++ : Konzepte, Perspektiven, Kompetenzen ; 1},
  editor    = {Petsche, Hans-Joachim},
  publisher = {Trafo},
  address   = {Berlin},
  isbn      = {978-3-86464-082-7},
  pages     = {168},
  year      = {2015},
  abstract  = {Die nun begonnene Reihe „studieren++" resultiert aus einer von der Universit{\"a}t Potsdam angebotenen Vorlesungsreihe. Das Besondere an dieser Vorlesungsreihe ist der multidisziplin{\"a}re Anspruch und die konsequent umgesetzte Zusammenarbeit {\"u}ber Disziplingrenzen hinweg. Die nicht nur {\"u}ber Instituts-, sondern {\"u}ber Fakult{\"a}tsgrenzen praktizierte Interdisziplinarit{\"a}t erlaubt die Betrachtung eines Problems oder Sachverhalts aus unterschiedlichen Blickwinkeln. Wissenschaftliche Fragestellungen sind komplex und nicht immer auf eine Disziplin beschr{\"a}nkt. Sie in ihrer G{\"a}nze erfassen und nachhaltige L{\"o}sungsstrategien oder Konzepte entwickeln zu k{\"o}nnen gelingt oft nur durch eine multidisziplin{\"a}re Kooperation. Eine Lehrveranstaltung wie die vorliegende ist nicht nur f{\"u}r die Studierenden einer Universit{\"a}t eine hervorragende M{\"o}glichkeit, um {\"u}ber die Grenzen der eigenen Disziplin hinaus zu blicken und die Zusammenarbeit mit Wissenschaftlerinnen und Wissenschaftlern aus anderen Bereichen zu pflegen. So lernt man, sich in andere Sichtweisen hineinzuversetzen und sich zwischen den Disziplinen zu bewegen - eine Kompetenz, die in der hochkomplexen Arbeitswelt von heute von hohem Nutzen ist. Der vorliegende erste Band der Reihe hat „Raum und Zahl" zum Thema und ist aus einer Ringvorlesung aus dem Wintersemester 2013/2014 entstanden. Drei der f{\"u}nf Fakult{\"a}ten, insgesamt neun Institute der Universit{\"a}t Potsdam, haben sich an der Vorlesung beteiligt und sich dieses spannenden Themas angenommen. Als jemand, der sich jahrelang wissenschaftlich mit algorithmischer Geometrie sowie mit raumbezogenen Datenbanken und Navigationssystemen besch{\"a}ftigt hat, kann ich nur bekr{\"a}ftigen, dass die Bez{\"u}ge zwischen Raum und Zahl, zwischen R{\"a}umen und Zahlen, noch viel st{\"a}rker im {\"o}ffentlichen Bewusstsein verankert geh{\"o}ren. R{\"a}ume auch quantitativ zu erfassen und zu verstehen ist eine Kulturtechnik, die an Wichtigkeit eher noch zunimmt, vor allem vor dem Hintergrund, dass wir genetisch nicht allzu gut auf derartige Herausforderungen vorbereitet sind. Denn viele unserer einschl{\"a}gigen Gene entstammen noch aus der Zeit der Savanne, einer Zeit, zu der das Raumkonzept sich fast ausschließlich auf die unmittelbare r{\"a}umliche Umgebung bezog und Zahlen jenseits von 10 nur wenig Relevanz f{\"u}r das eigene {\"U}berleben hatten. Als Pr{\"a}sident der Universit{\"a}t Potsdam freut es mich ganz besonders, dass sich die hier vertretenen Wissenschaftler bereit erkl{\"a}rt haben, ihre {\"U}berlegungen mit den Studierenden und ihren Kolleginnen und Kollegen zu teilen. Herrn Kollegen Hans-Joachim Petsche m{\"o}chte ich f{\"u}r sein Engagement danken und ihm zu dieser gelungenen Reihe gratulieren. Der Geist der Wissenschaft, der nicht nur einsam im B{\"u}ro oder Labor gelebt wird, sondern gerade an einer Universit{\"a}t auch aktiv nach außen getragen werden sollte, wird hier in besonderer Weise sichtbar. Ich w{\"u}nsche Ihnen viel Freude bei der Lekt{\"u}re des Bandes und freue mich auf weitere Ver{\"o}ffentlichungen in dieser Reihe.},
  subject      = {Raum},
  language  = {de}
}
@phdthesis{Sixtus2018,
  author    = {Sixtus, Elena},
  title     = {Subtle fingers - tangible numbers: The influence of finger counting experience on mental number representations},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420115},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vi, 138},
  year      = {2018},
  abstract  = {Numbers are omnipresent in daily life. They vary in display format and in their meaning so that it does not seem self-evident that our brains process them more or less easily and flexibly. The present thesis addresses mental number representations in general, and specifically the impact of finger counting on mental number representations. Finger postures that result from finger counting experience are one of many ways to convey numerical information. They are, however, probably the one where the numerical content becomes most tangible. By investigating the role of fingers in adults' mental number representations the four presented studies also tested the Embodied Cognition hypothesis which predicts that bodily experience (e.g., finger counting) during concept acquisition (e.g., number concepts) stays an immanent part of these concepts. The studies focussed on different aspects of finger counting experience. First, consistency and further details of spontaneously used finger configurations were investigated when participants repeatedly produced finger postures according to specific numbers (Study 1). Furthermore, finger counting postures (Study 2), different finger configurations (Study 2 and 4), finger movements (Study 3), and tactile finger perception (Study 4) were investigated regarding their capability to affect number processing. Results indicated that active production of finger counting postures and single finger movements as well as passive perception of tactile stimulation of specific fingers co-activated associated number knowledge and facilitated responses towards corresponding magnitudes and number symbols. Overall, finger counting experience was reflected in specific effects in mental number processing of adult participants. This indicates that finger counting experience is an immanent part of mental number representations. Findings are discussed in the light of a novel model. The MASC (Model of Analogue and Symbolic Codes) combines and extends two established models of number and magnitude processing. Especially a symbolic motor code is introduced as an essential part of the model. It comprises canonical finger postures (i.e., postures that are habitually used to represent numbers) and finger-number associations. The present findings indicate that finger counting functions both as a sensorimotor magnitude and as a symbolic representational format and that it thereby directly mediates between physical and symbolic size. The implications are relevant both for basic research regarding mental number representations and for pedagogic practices regarding the effectiveness of finger counting as a means to acquire a fundamental grasp of numbers.},
  language  = {en}
}