How do we decide when to act?

What did you do in the few seconds before reading this? Sit down and take out your phone? Scroll through some RUclips videos? Take a sip of a drink? While we think of these things as very simple actions - requiring hardly any thought at all - there are actually many complex processes taking place in your brain when they happen. These processes allow you to perfectly time each action, as neuroscientist Dr Nima Khalighinejad explains.