The role of numerical magnitude and order in the illusory perception of size and brightness

Abstract

Processing magnitudes constitutes a common experience across multiple dimensions, for example when one has to compare sizes, duration, numbers, sound height or loudness. From a cognitive point of view, however, it is still unclear whether all these experiences rely on a common system, or on distinct systems, with more or less strong associations. One particularly striking way of observing such interference between the spatial and numerical dimensions consists in eliciting a bias in size judgment through the mere perception of irrelevant numerical stimuli. In such experimental context though, two questions remain open. First, it is still unknown whether the direction of the bias is related to the magnitude of the number presented, or to their position in an ordinal sequence, and thus could be elicited by other non-numerical ordinal sequences such as letters of the alphabet. Second, it is still unclear whether the observed interactions generalize to other continuous dimension of magnitude such as brightness. In the study reported here, both letters and numbers were used in a size- and a brightness-reproduction task. We observed a dissociation between the two types of stimuli when reproducing size, the illusion being elicited solely by numbers. When reproducing brightness, however, neither the letters nor the numbers elicited a bias. These findings suggest that, while only numerical magnitude, and not letters, elicits a bias in size perception, the concurrent processing of magnitude and brightness does not bring about the same illusion, supporting the idea of a relative independence in the processing of these two dimensions.

The number–weight illusion

“…This corresponds to the often-confirmed and robust findings from numbersize congruency experiments reviewed in the Introduction demonstrating that larger (smaller) numbers are strongly associated with larger (smaller) physical size. In fact, in this broader perspective our findings connect well to classical studies (e.g., Bruner & Goodman, 1947) demonstrating that, e.g., the perceived diameter of coins is consistently influenced by the value indicated on it, not unlike the numbered balls in the present study (for corresponding recent grip aperture studies on how numbers influence perceived object size under conditions closely approximating those of the present study, see Andres et al, 2008, andViarouge &de Hevia, 2013). Ross and Gregory (1964) demonstrated that the Weber ratio in psychophysical weight judgments depends on perceived rather than on physical weight.…”

Is 9 louder than 1? Audiovisual cross-modal interactions between number magnitude and judged sound loudness

“…For example, the magnitudes of task-irrelevant symbolic numbers impact judgments about physical size and length (De Hevia, Girelli, Bricolo, & Vallar, 2008;A Henik & Tzelgov, 1982;Viarouge & de Hevia, 2013), numerosity (Naparstek & Henik, 2010), duration (AlardsTomalin, Leboe-McGowan, Shaw, & Leboe-McGowan, 2014;Kiesel & Vierck, 2009;Oliveri et al, 2008;Vicario et al, 2008;Xuan, Chen, He, & Zhang, 2009;Xuan, Zhang, He, & Chen, 2007), and luminance (i.e., brightness) (Cohen Kadosh et al, 2008;Cohen Kadosh, Henik, & Walsh, 2007; but see Pinel et al, 2004). Furthermore, they also interfere with basic spatial-motor response selection, including the performance speed of left vs. right handed responses (Dehaene, Bossini, & Giraux, 1993;Nuerk, Wood, & Willmes, 2005), precision motor responses (pinch vs. whole hand grasps) responses, and grip aperture (Andres, Ostry, Nicol, & Paus, 2008;Lindemann, Abolafia, Girardi, & Bekkering, 2007).…”

A left visual advantage for quantity processing in neonates

“…12). For these young populations, this lateralized relationship is present only when discrete quantity is introduced as a variable to be represented, suggesting that space and number have a uniquely close relationship 9,13–18 …”