Tactile enumeration: A case study of acalculia.

•Tactile enumeration and brain plasticity in acalculia following left IPS infarct.•Steep RT slope in acute phase and gradual decrease in slope over time.•VBM analysis shows increase in gray matter (GM) in right middle occipital cortex.•Results support tactile subitizing based on embodied pattern recognition.•Improved enumeration coincides with GM change supports “sense of magnitude” theory.