The popular 'model' that pilots are taught is the Yerkes-Dodson relationship between stress and arousal.
See:
http://www.nwlink.com/~donclark/hrd/...y/arousal.html
The approach and landing phase you mention has many other stresses than just effecting a safe touchdown. For example, the pilot may have considerations of fuel, ATC, weather, passenger sickness, flight duty limitations, tiredness/fatigue or variables of these.
In extreme circumstances a pilot may not want to go-round to avoid a more complicated situation.
The trick for the crew is to keep the general arousal level at about the right pitch. Too laid back and you don't process enough information to solve the problem.
Too worked up and you don't process enough information to solve the problem.
E.g. good advice for a technical problem at a busy airport might be to go into the hold and give yourself thinking space to troubleshoot. However, having this option requires the ability to plan ahead . . .
Plenty of scope for a good PHd project. Best of luck!