Separate mechanisms for magnitude and order processing in the spatial-numerical association of response codes (SNARC) effect: The strange case of musical note values.

Abstract

The SNARC effect is considered an evidence of the association between numbers and space, with faster left key-press responses to small numbers and faster right key-press responses to large numbers. We examined whether visually presented note values produce a SNARClike effect. Differently from numbers, note values are represented as a decreasing left-toright progression, allowing us to disambiguate the contribution of order and magnitude in determining the direction of the effect. Musicians with formal education performed a note value comparison in Experiment 1 (direct task), a line orientation judgment in Experiment 2 (indirect task), and a detection task in Experiment 3 (indirect task). When note values were task relevant (direct task), participants responded faster to large note values with the left key-press, and vice versa. Conversely, when note values were task irrelevant (indirect tasks), the direction of this association was reversed. This evidence suggests the existence of separate mechanisms underlying the SNARC effect. Namely, an Order-Related Mechanism (ORM) and a Magnitude-Related Mechanism (MRM), that are revealed by different task demands. Indeed, according to a new model we proposed, ordinal and magnitude related information seem to be preferentially involved in direct and indirect tasks, respectively.

The influence of time units on the flexibility of the spatial numerical association of response codes effect

“…In a recent study, Prpic et al . () dissociated these two types of information using musical symbols related to time duration and found that they were associated with different processing mechanisms. Additional studies are needed to explore how magnitude and order information are combined and processed from various perspectives using different materials and methods.…”

“…Besides our findings, non-numerical information can be divided into non-numerical magnitude information (e.g., time units, weight units, and length units) and non-numerical order information (e.g., months of the year and letters of the alphabet). In a recent study, Prpic et al (2016) dissociated these two types of information using musical symbols related to time duration and found that they were associated with different processing mechanisms. Additional studies are needed to explore how magnitude and order information are combined and processed from various perspectives using different materials and methods.…”

SNARC-like compatibility effects for physical and phenomenal magnitudes: a study on visual illusions

“…In Experiment 2 we decided to use an orientation task since previous studies (Fias, Lauwereyns & Lammertyn, 2001;Prpic, Fumarola, De Tommaso, Luccio, Murgia & Agostini, 2016;Mitchell, Bull & Cleland, 2012) showed that the processing of orientation interferes with both numerical and non-numerical magnitudes by eliciting a consistent SNARC-like effect. Indeed, orientation strongly relies on the parietal cortex where the magnitude system is located (Bueti & Walsh, 2009;Piazza et al, 2007;Van Opstal & Verguts, 2013).…”

Vertical spatial representation of numbers across two cultures

“…Those experiments have consistently shown that performance is more accurate and rapid when the physical positions of the production of responses to the numeric stimuli match the positions of the numeric stimuli within the mental representation of numbers (i.e., faster and more accurate judgement regarding larger numbers when the right hand is used to respond and vice versa). By using the SNARC paradigm, the spatial representation of numbers was observed not only for integer numbers (Dehaene et al, 1993), but also for fractional numbers (Bonato et al, 2007), negative numbers (Fischer, 2003), and even musical notes (Prpic et al, 2016). The mechanism underlying spatial-numerical associations is still debated (Gevers et al, 2010;Proctor & Cho, 2006, Van Dijck, Gevers, & Fias, 2009.…”