Picture yourself standing at the edge of a road, trying to decide if it’s safe to cross. It’s night time and rain is falling, making it difficult to see what’s up ahead. After looking both ways, you step onto the road. But what if this was a poor choice? Perhaps you’ve misjudged the speed of an approaching car. How does your brain realise its error and correct things before it’s too late? Experiments in cognitive psychology and neuroscience have taught us we make decisions by integrating information over time – that is, our brains collect and “add up” information across a very brief window of time, often only tens to hundreds of milliseconds, to form a clearer picture before committing to an action. But when we need to judge how appropriate a decision actually was, for example when we already have one foot on the road, we suddenly become selective. …