Thanks a lot! I really need some supervision and learning in terms of behavioral analysis.
If you want to change a behavior, you need to look at what the function of that behavior is. Functions of behavior could be: gaining attention, avoiding a task/demand, gaining access to something tangible, and the last is sensory stimulation. There are various data collection forms to use to determine function of behavior. One I use is an ABC data sheet. The A=Antecedent, B=Behavior and C=Consequence. Do you have access to a Behavior Analyst as part of your treatment team? That would be the best person to use as a resource for identifying the function of this behavior and formulating a plan for how to change it. I would look into any workshops that involve Applied Behavior Analysis, Functional Assessment and Behavior Interventions.
I wish I had some advise, but I don't. Maybe someone else here has a better idea. I think trying to distract him with something that he enjoys more (favorite toy or food) may help, but that's a guess.