Fig. 2
From: Mastering algebra retrains the visual system to perceive hierarchical structure in equations
Object-based attention for algebraic sub-expressions. Perceptual discriminability was modulated by whether perceptual comparison occurred within an algebraic sub-expression (i.e., variables separated by multiplication) or between algebraic sub-expressions (i.e., variables separated by addition). For Syntax Knowers, who exhibited mastery of the rules governing the hierarchical structure of algebra, discriminability was significantly better within algebraic sub-expressions. By contrast, Non-Knowers showed the opposite effect: better discriminability when comparing variables that were separated by lower-precedence addition. Error bars show SEM; *p < 0.05; **p < 0.01