Semantic associations between arithmetic and space: Evidence from temporal order judgements.

in Memory and Cognition (2020), 48(3), 361-369

Spatial biases associated with subtraction or addition problem solving are generally considered as reflecting leftward or rightward attention shifts along a mental numerical continuum, but an alternative ... [more ▼]

Spatial biases associated with subtraction or addition problem solving are generally considered as reflecting leftward or rightward attention shifts along a mental numerical continuum, but an alternative hypothesis not implying spatial attention proposes that the operator (plus or minus sign) may favour a response to one side of space (left or right) because of semantic associations. We tested these two accounts in a series of temporal order judgement experiments that consisted in the auditory presentation of addition or subtraction problems followed 200 ms (Experiments 1-2) or 800 ms (Experiment 3) later by the display of two lateralized targets in close temporal succession. To dissociate the side where the operation first brought their attention from the side they had to respond to, we asked participants to report which of the left or right target appeared first or last on screen. Under the attention-orienting account, addition should elicit more rightward responses than subtraction when participants have to focus on the first target, but more leftward responses when they have to focus on the last target, because the latter is opposite to the side where the operation first brought their attention. Under the semantic account, addition should elicit more rightward responses than subtraction, no matter the focus is on the first or last target, because participants should systematically favour the side conceptually linked to the operator. The results of the three experiments converge to indicate that, in lateralized target detection tasks, the spatial biases induced by arithmetic operations stem from semantic associations. [less ▲]

Spatial biases in mental arithmetic are independent of reading/writing habits: Evidence from French and Arabic speakers.

in Cognition (2020), 200

The representation of numbers in human adults is linked to space. In Western cultures, small and large numbers are associated respectively with the left and right sides of space. An influential framework ... [more ▼]

The representation of numbers in human adults is linked to space. In Western cultures, small and large numbers are associated respectively with the left and right sides of space. An influential framework attributes the emergence of these spatial-numerical associations (SNAs) to cultural factors such as the direction of reading and writing, because SNAs were found to be reduced or inverted in right-to-left readers/writers (e.g., Arabic, Farsi, or Hebrew speakers). However, recent cross-cultural and animal studies cast doubt on the determining role of reading and writing directions on SNAs. In this study, we assessed this role in mental arithmetic, which requires explicit number manipulations and has revealed robust leftward or rightward biases in Western participants. We used a temporal order judgement task in French and Arabic speakers, two languages that have opposite reading/writing directions. Participants had to solve subtraction and addition problems presented auditorily while at the same time determining which of a left or right visual target appeared first on a screen. The results showed that the right target was favoured more often when solving additions than when solving subtractions both in the French- (n = 31) and Arabic-speaking (n = 25) groups. This was true even in Arabic-speaking participants whose preference for ordering of various series of numerical and non-numerical stimuli went from right to left (n = 10). These results indicate that SNAs in mental arithmetic cannot be explained by the direction of reading/writing habits and call for a reconsideration of current models to acknowledge the pervasive role of biological factors in SNAs in adults. [less ▲]

Canonical finger numeral configurations are perceived holistically

Poster (2014, April 04)

Sooner or later human beings represent or see numerosities represented by hands. This handling of small numerosities by prototypical finger configurations has been the focus of many experiments ... [more ▼]

Sooner or later human beings represent or see numerosities represented by hands. This handling of small numerosities by prototypical finger configurations has been the focus of many experiments investigating the possibility that semantic representations of numbers are motor-rooted. Canonical finger configurations (i.e. the culturally determined way to express numerosity with fingers) are for instance recognized faster (Di Luca et al., 2006), and give direct access to number semantics (Di Luca et Pesenti, 2008). It is also known that these effects are not due to a visual facilitation of canonical configurations (Di Luca et Pesenti, 2010), but to a different inner representation (Di Luca, Lefèvre and Pesenti, 2010). However, a precise characterization of their visual processing is currently lacking. We addressed this shortcoming by using an eye-tracking method based on gaze-contingent stimulus presentation (Van Belle et al., 2010). While participants named numerosities expressed by canonical and non-canonical finger numeral configurations presented in upright or inverted orientations, we selectively impaired analytical or holistic visual perception by respectively masking (in real time) peripheral or focal vision. Our data confirm the results found in literature: canonical configurations are processed faster than non-canonical ones, upright configurations are processed faster than inverted ones and holistic perception is faster than analytical one. Most importantly, we also demonstrate that canonical configurations are impaired by the peripheral mask (i.e. holistic vision hindered) whereas non-canonical ones are impaired by the foveal mask (i.e. analytical vision hindered). These results confirm that the practice of finger numeral configurations modifies not only the way human beings process and represent numerosities but especially the way to visually perceive them. [less ▲]

Numbers reorient visuo-spatial attention during cancellation tasks

in Experimental Brain Research (2013), 225(4), 549-57

Numbers induce shifts of spatial attention on the left or the right sides of external space as a function of their magnitude. However, whether this number-space association is restricted to the linear ... [more ▼]

Numbers induce shifts of spatial attention on the left or the right sides of external space as a function of their magnitude. However, whether this number-space association is restricted to the linear horizontal extensions, or extends to the whole visual scene, is still an open question. This study investigates, by means of a cancellation paradigm, the influence of numerical magnitude during scanning tasks in which participants freely explore complex visual scenes unconstrained towards either the horizontal or the vertical unidimensional axes. Five cancellation tasks were adapted in which Arabic digits were used as targets or distracters, in structured (lines and columns) or unstructured visual displays, with a smaller (2 or 3 types of distracters) or larger (10 or more types of distracters) sets of stimuli. Results show that the participants' hits distribution was a function of number magnitude: shifted on the left for small and on the right for large numbers. This effect was maximised when numerical cues were sparse, randomly arranged and, critically, irrelevant to the task. Overall, this study provides novel evidence from visuo-spatial exploratory cancellation tasks for an attentional shift induced by number magnitude. [less ▲]

Place and summation coding for canonical and non-canonical finger numeral representations

in Cognition (2010), 117(1), 95-100

Fingers can be used to express numerical magnitudes, and cultural habits about the fixed order in which fingers are raised determine which configurations become canonical and which non-canonical. Although ... [more ▼]

Fingers can be used to express numerical magnitudes, and cultural habits about the fixed order in which fingers are raised determine which configurations become canonical and which non-canonical. Although both types of configuration carry magnitude information, it has been shown that the canonical ones are recognized faster and directly linked to number semantics. Here we tested whether this difference is a consequence of differences in the qualitative way of processing the two types of configurations. When participants named Arabic digits (Experiment 1) or verbal numerals (Experiment 2) primed by canonical and non-canonical finger configurations, qualitatively different priming patterns were observed for the two types of configurations. Canonical configurations activated a place coding representation, with priming spreading to close smaller and larger magnitudes as a function of the prime-target distance. Conversely, non-canonical configurations activated a summation coding representation priming smaller and equal magnitudes independently of the prime-target distance, and larger targets depending on this distance. [less ▲]

Let us redeploy attention to sensorimotor experience

in Behavioral and Brain Sciences (2010), 33(4), 283

With his massive redeployment hypothesis (MRH), Anderson claims that novel cognitive functions are likely to rely on pre-existing circuits already possessing suitable resources. Here, we put forward ... [more ▼]

With his massive redeployment hypothesis (MRH), Anderson claims that novel cognitive functions are likely to rely on pre-existing circuits already possessing suitable resources. Here, we put forward recent findings from studies in numerical cognition in order to show that the role of sensorimotor experience in the ontogenetical development of a new function has been largely underestimated in Anderson’s proposal. [less ▲]

Finger counting: The missing tool?

in Behavioral and Brain Sciences (2008), 31

Rips et al. claim that the principles underlying the structure of natural numbers cannot be inferred from interactions with the physical world. However, they failed to consider an important source of ... [more ▼]

Rips et al. claim that the principles underlying the structure of natural numbers cannot be inferred from interactions with the physical world. However, they failed to consider an important source of interaction: finger counting. Here, we show that finger counting satisfies all the conditions required for allowing the concept of numbers to emerge from sensorimotor experience through a bottom-up process. [less ▲]

Finger-digit compatibility in Arabic numeral processing

in Quarterly Journal of Experimental Physiology (2006), 59(9), 1648-63

Finger-digit response compatibility was tested by asking participants to identify Arabic digits by pressing one of ten keys with all ten fingers. The direction of the finger-digit mapping was varied by ... [more ▼]

Finger-digit response compatibility was tested by asking participants to identify Arabic digits by pressing one of ten keys with all ten 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 a mapping congruent with the prototypical finger-counting strategy reported by the participants leads to better performance than a mapping congruent with a left-to-right oriented mental number line, and demonstrate that finger-counting strategies clearly influence the way numerical information is mentally represented and processed. [less ▲]