Which numbers do you have in mind? Number generation is influenced by reading direction

Abstract

In Western participants, small numbers are associated with left and larger numbers with right space. A biological account proposes that brain asymmetries lead to these attentional asymmetries in number space. In contrast, a cultural account proposes that the direction of this association is shaped by reading direction. We explored whether number generation is influenced by reading direction in participants from a left-to-right (UK) and a right-to-left (Arab) reading culture. Participants generated numbers randomly while lying on their left and right side. The mean number generated by participants from a left-to-right reading culture was smaller when they lay on their left than on their right side, and the opposite was found for participants from a right-to-left reading culture. Asymmetries in number space observed in number generation are more compatible with a cultural than biological account.

The Possibility of Uniform Pseudo-random Number Generation by a Group of Humans

“…Confirming earlier researches, it was discovered that children and adults tend to have biases for big and small numbers respectively. Researchers have identified factors which can influence number generation by humans to include lateral head turn [15], mental state [22], reading direction [9], hand and mouth action [11] and composite body movement [5]. The study in [24] affirms previous findings revealing the effect of active head rotation on the randomization of numbers in adults who were observed to generate smaller numbers during left rather than right rotation.…”

Random word generation reveals spatial encoding of syllabic word length

“…Conversely, a study by Fern andez, Rahona, Herv as, V azquez, and Ulrich (2011) demonstrated that number magnitude affects free gaze choice by showing that participants are more likely to choose to look left after fixating small numbers and right after fixating large numbers. Other studies showed similar left-to-right biases in RNG studies involving other effectors: finger tapping (Plaisier & Smeets, 2011;Vicario, 2012) and whole-body turns (G€ obel, Maier, & Shaki, 2015;Shaki & Fischer, 2014). Taken together, these production studies demonstrate that spatial-numerical biases do not only accompany bottom-up number processing but are also present during top-down number generation.…”

The influence of semantic processing and response latency on the SNARC effect

“…The MNL is a semantic long-term memory representation in which numbers are coded on a unidimensional conceptual space, horizontally organized in ascending order from left to right: small numbers are encoded on the left side and large numbers on the right side (Hubbard et al, 2005). This spatial organization is thought to emerge from cultural practices such as writing/reading direction (Göbel, 2015;Göbel, Maier, & Shaki, 2015;Göbel, Shaki, & Fischer, 2011; for a right-to-left spatial orientation of the MNL in non-Western cultures see Shaki, Fischer, & Göbel, 2012;Shaki, Fischer, & Petrusic, 2009). According to the MNL account, the SNARC effect emerges from an isomorphism (i.e., a direct mapping) between the position of a number on this semantic representation and the left-right coordinates of the external response locations.…”