Operational momentum affects eye fixation behaviour.
The operational momentum effect (OM) indicates an association of mental addition with a rightward spatial bias, whereas subtraction is associated with a leftward bias. To evaluate the assumed attentional origin of the OM effect, we evaluated not only participants' relative estimation error in a task requiring them to locate addition and subtraction results on a given number line but also their eye-fixation behaviour. Furthermore, to investigate the situatedness of spatial-numerical associations, the orientation of the number line (left-to-right vs. right-to left) was manipulated. OM biases in participants' explicit number line estimations and more implicit eye-fixation behaviour are integrated into a two-process hypothesis of the OM effect suggesting a first rough spatial anticipation followed by an evaluation/correction process. This account not only is capable of accounting for the results observed for participants' relative estimation error but is also corroborated by the eye-fixation results. Importantly, the fact that all effects were found independent of the orientation of the number line indicates that spatial-numerical associations such as the OM effect may not be hard-wired associations of spatial and numerical representations but rather reflect influences of situatedness on numerical cognition.
a KMRC-Knowledge Media Research Center , Neurocognition Lab , Tuebingen , Germany.
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E
Klein
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S
Huber
H C
HC
Nuerk
K
K
Moeller
D000328:Adult; D001244:Association; D001288:Attention / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D008433:Mathematics; D008606:Mental Processes / Q000502:physiology*; D010775:Photic Stimulation; D011340:Problem Solving; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D055815:Young Adult
Eye-fixation behaviour; Mental number line; Numerical cognition; Operational momentum; Spatial–numerical associations