A person certified by the national Behavior Analyst Certification Board who may work with your child, staff and family members to use modifications changes in the environment and instruction to produce create improvements in behavior.

Assesses the function of a behavior of an individual and designs, implements, and evaluates instructional and environmental modifications to produce socially significant improvements in the individual’s behavior through skill acquisition and the reduction of behavior. Duties and qualifications pursuant to Title 17 of the CCR section 54342(a)(11) remain the same.

Your family member seems to be in their own world, isolates themselves, and plays the same video game over and over all the time. A behavior analyst can work with the individual over time to gradually introduce other options that might interest them and to engage them in more social interaction.