TY  - GEN
A1  - Shaki, Samuel
A1  - Fischer, Martin H.
T1  - Competing Biases in Mental Arithmetic
BT  - When Division Is More and Multiplication Is Less
N2  - Mental arithmetic exhibits various biases. Among those is a tendency to overestimate addition and to underestimate subtraction outcomes. Does such “operational momentum” (OM) also affect multiplication and division? Twenty-six adults produced lines whose lengths corresponded to the correct outcomes of multiplication and division problems shown in symbolic format. We found a reliable tendency to over-estimate division outcomes, i.e., reverse OM. We suggest that anchoring on the first operand (a tendency to use this number as a reference for further quantitative reasoning) contributes to cognitive biases in mental arithmetic.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 312 
KW  - heuristics and biases
KW  - mental arithmetic
KW  - mental number line
KW  - numerical cognition
KW  - operational momentum
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-103492
ER  - 
TY  - GEN
A1  - Shaki, Samuel
A1  - Fischer, Martin H.
T1  - Newborn chicks need no number tricks
BT  - Commentary: Number-space mapping in the newborn chick resembles humans' mental number line
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - kein Abstract
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 414 
KW  - mental number line
KW  - innate number sense
KW  - numerical cognition
KW  - spatial cognition
KW  - spatial numerical associations
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-406425
IS  - 414
ER  - 
TY  - GEN
A1  - Hartmann, Matthias
A1  - Mast, Fred W.
A1  - Fischer, Martin H.
T1  - Spatial biases during mental arithmetic
BT  - evidence from eye movements on a blank screen
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - While the influence of spatial-numerical associations in number categorization tasks has been well established, their role in mental arithmetic is less clear. It has been hypothesized that mental addition leads to rightward and upward shifts of spatial attention (along the "mental number line"), whereas subtraction leads to leftward and downward shifts. We addressed this hypothesis by analyzing spontaneous eye movements during mental arithmetic. Participants solved verbally presented arithmetic problems (e.g., 2 + 7, 8-3) aloud while looking at a blank screen. We found that eye movements reflected spatial biases in the ongoing mental operation: Gaze position shifted more upward when participants solved addition compared to subtraction problems, and the horizontal gaze position was partly determined by the magnitude of the operands. Interestingly, the difference between addition and subtraction trials was driven by the operator (plus vs. minus) but was not influenced by the computational process. Thus, our results do not support the idea of a mental movement toward the solution during arithmetic but indicate a semantic association between operation and space.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 426 
KW  - mental arithmetic
KW  - eye movements
KW  - mental number line
KW  - operational momentum
KW  - embodied cognition
KW  - grounded cognition
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-406504
IS  - 426
ER  - 
TY  - GEN
A1  - Fischer, Martin H.
A1  - Shaki, Samuel
T1  - Two steps to space for numbers
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 412 
KW  - spatial-nunmerical association
KW  - SNARC
KW  - mental number line
KW  - numerical cognition
KW  - spatial cognition
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-406522
IS  - 412
ER  -