The concept of mental toughness is fairly modern, the idea is that it is various personal attributes and skills a person has to cope with difficult situations.
The human body has evolved to have a fight or flight response to what our brains consider scary situations. By understanding what the common response and behavioural effects are we can start to become aware of when we trigger that response and start to rationalise what we feel.
99% of athletes report using some kind of visualisation in their training or sport. Whilst for many it is just an image, we are going to cover the PETTLEP model of imagery which shows that imagery is a combination of a visual image, kinaesthetic feeling and an emotional response.