The activity of neurons carries information because they become active only in particular situations. This is called ‘selectivity’, and it allows a group of neurons to signal the state of the world. We may remember things either by keeping neurons active, or by changing their selectivities. However, we haven’t really worked out how changing a neuron’s selectivity works, to help us perform tasks. Here in Bocincova et al. PNAS (2022) (free) we find that neurons in prefrontal cortex change their selectivity to form short-term “bindings” between features, allowing flexible working memory.