Mathematics requires thinking but also pattern recognition. Recent research indicates that perceptual learning (PL) interventions facilitate discovery of structure and recognition of patterns in mathematical domains, as assessed by tests of mathematical competence. Here we sought direct evidence that a brief perceptual learning module (PLM) produces changes in basic information extraction. Accuracy and speed of undergraduate participants' encoding of equations was assessed in a psychophysical task at pretest and delayed posttest. In between, the experimental group completed an "Algebraic Transformations PLM," which involved identifying valid transformations of equations. Relative to controls, PLM participants showed reliable changes in encoding equations, detectable psychophysically 24 hours later. Encoding improvements were shown robustly by participants who were initially less proficient at algebra and were negligible for participants who were initially proficient. These results provide direct evidence for durable changes in information encoding produced by a PL intervention targeting a complex mathematical skill.