***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Access to mental representations of smaller vs. larger number symbols is associated with leftward vs. rightward spatial locations , as represented on a number line . The well-replicated SNARC effect ( Spatial-Numerical Association of Response Codes ) reveals that simple decisions about small numbers are facilitated when stimuli are presented on the left , and large numbers facilitated when on the right . We present novel evidence that the size of the SNARC effect is relatively stable within individuals over time . This enables us to take an individual differences approach to investigate how the SNARC effect is modulated by spatial and numerical cognition . Are number-space associations linked to spatial operations , such that those who have greater facility in spatial computations show the stronger SNARC effects , or are they linked to number semantics , such that those showing stronger influence of magnitude associations on number symbol decisions show stronger SNARC effects ? Our results indicate a significant correlation between the SNARC effect and a  2D mental rotation task  , suggesting that spatial operations are at play in the expression of this effect . We also uncover a significant correlation between the SNARC effect and the distance effect , suggesting that the SNARC is also related to access to number semantics . A multiple regression analysis reveals that the relative contributions of spatial cognition and distance effects represent significant , yet distinct , contributions in explaining variation in the size of the SNARC effect from one individual to the next . Overall , these results shed new light on how the spatial-numerical associations of response codes are influenced by both number semantics and spatial operations 
    Output:
    
Additional analyses revealed a significant effect size advantage for explicit instruction tasks compared with implicit instructions , yet yielded no difference for the role of expertise on SNARC-like effects .
The similarities in the response properties for the spatial mappings of numerical and non-numerical domains support the concept of a general higher order magnitude system .