The Impact of Symbolic and Non-Symbolic Quantity on Spatial Learning

An implicit mapping of number to space via a “mental number line” occurs automatically in adulthood. Here, we systematically explore the influence of differing representations of quantity (no quantity, non-symbolic magnitudes, and symbolic numbers) and directional flow of stimuli (random flow, left-to-right, or right-to-left) on learning and attention via a match-to-sample working memory task. When recalling a cognitively demanding string of spatial locations, subjects performed best when information was presented right-to-left. When non-symbolic or symbolic numerical arrays were embedded in these spatial locations, and mental number line congruency prompted, this effect was attenuated and in some cases reversed. In particular, low-performing female participants who viewed increasing non-symbolic number arrays paired with the spatial locations exhibited better recall for left-to-right directional flow information relative to right-to-left, and better processing for the left side of space relative to the right side of space. The presence of symbolic number during spatial learning enhanced recall to a greater degree than non-symbolic number—especially for female participants, and especially when cognitive load is high—and this difference was independent of directional flow of information. We conclude that quantity representations have the potential to scaffold spatial memory, but this potential is subtle, and mediated by the nature of the quantity and the gender and performance level of the learner

Recall performance in Structured vs. Non-Structured Sequences.

<p>Mean recall performance (% correct) in each experiment, contrasting a composite score for structured (LR and RL) trials in green vs. random structure (IND) trials in red. Error bars reflect the between-subjects SEM. The benefit of structure was apparent in all experiments (asterisks indicate a significant difference with an alpha level of. 05), and significantly greater in the cognitively demanding symbolic number condition.</p

Effect of Spatial Flow on Spatial Location Recall for Experiment 1.

<p>Participants’ performance at each position in the 10-panel recall string (T10) for Experiment 1: Space Only, for the left-to-right structured and right-to-left structured spatial flow types. Error bars are the within-subject standard error of the mean (SEM).</p

Spatial recall for Experiment 2: Non-symbolic Number Arrays.

<p>Female and male participants’ performance in Experiment 2: Non-Symbolic Number at each string length (1 panel up to 10 panels), for the left-to-right structured and right-to-left structured spatial flow types. Error bars are the within-subject SEM.</p

Impact of spatial flow type on recall.

<p>Participants’ performance differential for the two horizontal spatial flow types (LR—RL). The asterisk reflects a significant difference between the experiments at an alpha level of. 05, and error bars depicted are the SEM of each group.</p

Experimental Schematic and Embedded Numerical Stimuli.

<p>Schematic of stimuli and spatial flow for Experiments 2, 3A, and 3B (left-to-right flow shown). In Experiment 2 the non-symbolic arrays were embedded in spatial locations as they appeared on the screen, and in Experiment 3A and 3B the symbolic numerals were embedded in the center of each location as it appeared.</p