The economic model of behaviour would suggest that we make rational decisions based on our goals. So if we want to lose weight we will stop eating cake. Yet we all know this is not what actually happens.
Neuroscience is coming up with a different hypothesis: that we actually make a comparison between ourselves now and ourselves in the future – i.e. when we have lost the weight. There is evidence that some people think about their future self like we think about another person; a disassociated view of what we could call 'this new self'. The new self is viewed as quite different from our current self. Other people view their future self as much more similar to their current self; the same but thinner for example. We could call this modified self. The degree of alignment between our current and future self can determine how good we are at making predictions about achieving goals. If there is a big difference between how we view our current and how we view our future self; the new self tendency, this can lead us to make predictions that our future self will want different things to our current self.
This is important because it helps or hinders us achieve our goals to change. The extent to which we understand our own mind in the future, for example, how rewarded we know we will feel if we reach our goals has an impact on whether we resit temptations and stay focused on goals in the present. So if our goal is to be thin or reach a particular job level, for example, is based on a picture of our self as modified as opposed to new we are more likely to resist temptation and stick with the goal. These people have the same level of activation in their Medial Prefrontal cortex when thinking about them self now and in the future.
The lesson? Check your picture of your future self. If it is wildly different to your current self you might want to modify the picture. Also check you have a realistic self-image. How well you know yourself is an important start point for changing.