Within the NFL there are a great number of quarterbacks, including both starters and backups. Both the starters and the backups are equally responsible for learning, knowing and understanding the entire offensive scheme of their particular team and the defensive scheme of their opponents. These schemes or playbooks can be quite massive such as the Oakland Raiders offensive playbook which is 800 pages. In the NFL throughout the entire season the starting quarterbacks take every single practice snap at every practice unless their injured or tired. Despite this fact, the backup quarterbacks are required to know all of the same information and be ready to play at a moment's notice. The article below further explains the difficulties faced by backup quarterbacks attempting to learn offenses.
As a result, backup quarterbacks face a number of psychological hurdles one of which is proactive interference. One prime example of proactive interference faced by an NFL quarterback is Carson Palmer's case. He was traded from the Bengals to the Raiders less than a week ago, but is now going to be expected to start. This means that he is going to have to learn the entire 800 page offensive playbook, while having to deal with proactive interference. Palmer played for several years on the Bengals and as a result knew their playbook very well but now has learn all the new plays, some of which may be the exact same with different names. Since many of the play concepts will be similar but slightly different and have different names he is likely going to have issues with proactive inference, in learning the offense. Despite this fact he is expected to learn the playbook without being confused and then recall it entirely under stressful situations and correctly execute the plays. This concept of trading NFL quarterbacks and expecting them to learn, remember and perform under these circumstances is mind boggling to me because of the numerous psychological hurdles they face particularly in dealing with proactive interference.