Number magnitude potentiates action judgements

Abstract

Motor actions can be simulated and generated through the perception of objects and their characteristics. Such functional characteristics of objects with given action capabilities are called affordances. Here we report an interaction between the perception of affordances and the processing of numerical magnitude, and we show that the numerical information calibrates the judgement of action even when no actual action is required. In Experiment 1, participants had to judge whether they would be able to grasp a rod lengthways between their thumb and index finger. The presentation of the rod was preceded by a number or a non-numerical symbol. When a small number preceded the rod, participants overestimated their grasp; conversely, when a large number preceded the rods, they underestimated their grasp. In Experiment 2, participants were requested to judge if two successive rods had the same length, a judgement that did not involve any grasping. The numerical primes had no effect on this judgement, showing that the magnitude/affordance interaction was not due to a simple perceptual effect. Finally, Experiment 3 showed that the interaction was not present with a non-numerical ordered sequence, thereby eliminating sequence order as a potentially confounding variable.

Number generation bias after action observation

“…The present experiment differs from the latter studies as no actual movement was performed or experienced by the participants themselves, but it demonstrates a similar causal link, here between grip movement observation and number selection and production. This finding adds with previous studies showing that small-and large-magnitude numbers prime grip closing and grip opening, respectively; conversely, grip closing primes the processing of small-magnitude numbers whereas perceiving a grip opening does not produce such a priming effect (Andres et al 2004;Badets et al 2007;Pesenti 2010, 2011;Lindemann et al 2007). Compared with these studies, the present study used a random generation task designed to assess the characteristics of the elements produced and not the speed at which each element was produced, the participants being explicitly instructed not to give speeded responses.…”

“…It has also been shown that numerical magnitude influences the judgement of actions towards objects (e.g. estimating whether rods of various length could be grasped between the index finger and the thumb after processing a small-or a large-magnitude number) without actually performing the action (Badets et al 2007). Interestingly, action observation also influences numerical processing: observing a grip closing posture slows down the processing of large-magnitude numbers, whereas observing a grip opening does not produce any priming or interference effect Pesenti 2010, 2011).…”

When time is space: Evidence for a mental time line

“…The previously mentioned studies by Miles et al (2010) and by Núñez and Sweetser (2006) are rather striking examples of embodiment in time processing. These findings again parallel the numerical domain, where effects of numerical magnitudes on affordances have been documented (Badets et al, 2007). We reiterate that one crucial (though overlooked) embodied aspect of time-space interactions derives from writing direction, which primes the direction of these associations Ouellet et al, 2010b;Tversky et al, 1991;Miles et al, 2011).…”

Selective interference of grasp and space representations with number magnitude and serial order processing

“…More generally, these results validate the use of SRC effects to assess dimensional overlap between cognitive and sensory-motor processes (Fias, Lauwereyns, & Lammertyn, 2001). Previous observations have shown that our ability to grasp an object is overestimated (or underestimated) when the object is preceded by the presentation of small (or large) numbers, whereas such a bias is not observed when the object is preceded by the presentation of the first (or last) letters of the alphabet (Badets, Andres, Di Luca, & Pesenti, 2007). However, the lack of explicit instructions to process alphabetical order in this study may have decreased the saliency of order information during grasping judgments (Gevers, Reynvoet, & Fias, 2003).…”