Feedback works when the person can hold in mind how they behave now and how they would behave in the future. In effect this means people can feed forward and to create a mental picture of the new behaviour. Scientist call this mental contrasting.
The critical reason this is important is that the person can see all the elements that differ in the new behaviour compared to the old. Scientists believe this mental contrasting helps generate both the insight that change would be beneficial, the motivation to undertake the change and the details of the different behaviours required. When people are undertaking mental contrasting scientist see they are thinking in a complex way, it engages the prefrontal cortex as well as the temporal lobe which is essential for accessing the memory of the past (current behaviour) with a vision of the new behaviour in the future. The researchers also see activation in the visual areas of the brain.
This amount of processing is very energy draining for the brain. It requires a lot of mental resources so is hard when people are under threat, are very stressed or are focused on defending their reputation.
This research gives us some insight into why feed forward seems to work. A feed forward system which allows the employee to work out how they will behave in the future is likely to also be activating mental contrasting, and creating insight rather than telling the employee what to do in the future. Introducing this kind of feedback approach requires a shift in the power structure between managers and employees and training for both.
Of course this is not just relevant to feedback. Any behavioural change needs mental contrasting to help direct the subtle shifts which are needed. This short video talks about the research in relation to goals covers some more of the science