Your brain finds it easy to size up four objects but not five — here’s why Nature, Published online: 06 October 2023; doi:10.1038/d41586-023-03136-wNeuron activity shows that the brain uses different systems for counting up to four, and for five or more. #press https://www.nature.com/articles/d41586-023-03136-w?utm_source=press.coop