Finger–digit compatibility in Arabic numeral processing

Abstract

Finger-digit response compatibility was tested by asking participants to identify Arabic digits by pressing 1 of 10 keys with all 10 fingers. The direction of the finger-digit mapping was varied by manipulating the global direction of the hand-digit mapping as well as the direction of the finger-digit mapping within each hand (in each case, from small to large digits, or the reverse). The hypothesis of a left-to-right mental number line predicted that a complete left-to-right mapping should be easier whereas the hypothesis of a representation based on finger counting predicted that a counting-congruent mapping should be easier. The results show that when all 10 fingers are used to answer, a mapping congruent with the prototypical finger-counting strategy reported by the participants leads to better performance than does a mapping congruent with a left-to-right oriented mental number line, both in palm-down and palm-up postures of the hands, and they demonstrate that finger-counting strategies influence the way that numerical information is mentally represented and processed.

Are numbers special? An overview of chronometric, neuroimaging, developmental and comparative studies of magnitude representation

“…The only area that showed a preference for the calculation task was the anterior part of the left IPS, similar to other later findings (Cohen Kadosh et al, 2005;Fias et al, 2003). One could argue that such activation might be the result of digital representation, which is used for counting (Butterworth, 1999;Di Luca et al, 2006;Göbel et al, 2004;Kansaku et al, 2006), and not from a numerical representation per se. However, the results from control tasks of grasping and pointing, which used digital movement, refute such an argument.…”

“…However, the results from control tasks of grasping and pointing, which used digital movement, refute such an argument. Moreover, no area in the parietal lobe showed a joint activation for calculation and grasping, thus, challenging the idea of digital representation as being part of numerical processing (Butterworth, 1999;Di Luca et al, 2006). However, it should be noted that the calculation task yielded the slowest RT among all tasks.…”

Touch perception reveals the dominance of spatial over digital representation of numbers

“…Therefore, even when emphasis was given to fingers and might have in principle favored a finger-based numerical representation, the results were clear in showing a space-based dominance in number representation. When compared with previous studies, it is noteworthy that the present findings were obtained within a best-suited approach to disambiguate between number representations: First, number magnitude was totally task-irrelevant, at odds with previous visuomotor number-finger mapping task (24); second, a single centrally located effector was used, at variance with SNARC tasks whereby two left-right horizontally aligned effectors are typical used (14,17); finally, the foot was used as response effector, i.e., a body part that is not used to learn counting.…”

“…contrast, finger-based dominance has been suggested by Di Luca et al (24), who asked subjects to perform a visuomotor finger-number compatibility task and found better performance when the mapping was congruent with the prototypical finger-counting strategy. In addition, a certain degree of flexibility in number representation has been recently suggested (25)(26)(27)(28), because the mapping between numbers and space can vary to some extent with instructional context (25) and task demands (17).…”

The role of vision in the development of finger–number interactions: Finger-counting and finger-montring in blind children

“…Canonical finger configurations were also reported to be reactivated when adults need to retrieve the result of simple arithmetic operations (Badets, Pesenti, & Olivier, 2010). Finally, Di Luca, Granà, Semenza, Seron, and Pesenti (2006) showed that Italian participants identify Arabic digits from 1 to 10 faster and more accurately when the finger used to press the response button corresponds to the canonical Italian finger-digit mapping (i.e., from the right thumb to the right little finger for numbers 1-5 and from the left thumb to the left little finger for numbers 6-10).…”