What is the type of research method that focuses on the relationship between physiological processes and behavior?

Answer: The research method is known as psychophysiological.

Explanation: Psychophysiology is a branch of physiology that deals with the interaction between the mind (psyche) and physiological processes (body).

This study research how the mind and body respond in relation their activities.

An example of this is the fact when an individual is stressed (body) thinking (mind) can make the stress significantly worse.

Or overthinking (mind) can cause an individual to have high blood pressure (body). The relationship between these interactions is termed Psychophysiology.