Single-digit Arabic numbers do not automatically activate magnitude representations in adults or in children: Evidence from the symbolic same–different task

Abstract

We investigated whether the mere presentation of single-digit Arabic numbers activates their magnitude representations using a visually-presented symbolic same–different task for 20 adults and 15 children. Participants saw two single-digit Arabic numbers on a screen and judged whether the numbers were the same or different. We examined whether reaction time in this task was primarily driven by (objective or subjective) perceptual similarity, or by the numerical difference between the two digits. We reasoned that, if Arabic numbers automatically activate magnitude representations, a numerical function would best predict reaction time; but if Arabic numbers do not automatically activate magnitude representations, a perceptual function would best predict reaction time. Linear regressions revealed that a perceptual function, specifically, subjective visual similarity, was the best and only significant predictor of reaction time in adults and in children. These data strongly suggest that, in this task, single-digit Arabic numbers do not necessarily automatically activate magnitude representations in adults or in children. As the first study to date to explicitly study the developmental importance of perceptual factors in the symbolic same–different task, we found no significant differences between adults and children in their reliance on perceptual information in this task. Based on our findings, we propose that visual properties may play a key role in symbolic number judgements.

Limited-capacity identity processing of multiple integers

“…As such, this work is akin to that undertaken by researchers in their quest to understand how processes concerning visual featural and letter encoding inform more general theories concerning the mental architecture underpinning word recognition and reading (see, e.g., McClelland & Rumelhart, 1981;Rumelhart & Siple, 1974). Although, historically, these "low-level" processes have not featured heavily in traditional accounts, there is now a growing body of evidence that these need to be considered if adequate models of numerical cognition are to be developed (see Cohen, 2009Cohen, , 2010Cohen & Quinlan, 2016;Cohen, Warren, & Blanc-Goldhammer, 2013;Defever, Sasangie, Vandewaetere, & Reynvoet, 2012;García-Orza, Perea, Mallouh, & Carreiras, 2012;Wong & Szücs, 2013;Zhang, Xin, Feng, Chen, & Szücs, 2018).…”

Separating stages of arithmetic verification: An ERP study with a novel paradigm

“…Investigating arithmetic problem solving by means of a typical arithmetic verification paradigm confounds all the above processes, preventing one from drawing clear conclusions on the temporal structure of the cognitive events involved in arithmetic verification decision. An important factor is that numerical magnitude comparison can be affected by task-relevant non-numerical discrimination processes rather than by number specific representational effects (Van Opstal and Verguts, 2011;Wong and Szűcs, 2013). Therefore, the task relevancy of correctness judgements in verification tasks introduces a major confound.…”

Common magnitude representation of fractions and decimals is task dependent

“…In spite of no distance effect, however, it should be noted that fractions and decimals should be converted into a common representation in the matching task. Several recent studies have argued that the perceptual physical similarity between Arabic numbers other than the numerical distance contributes to the numerical processing in the matching task (e.g., Cohen, 2009;Defever, Sasanguie, Vandewaetere, & Reynvoet, 2012;Garcia-Orza, Perea, Abu Mallouh, & Carreiras, 2012;Wong & Szűcs, 2013). In this study, however, it was unlikely that participants transformed the fraction into a decimal using the semantic system, and then quitted using the semantic system and switched to a perceptual system for the comparison phase.…”