Movie directors discovered that they can film different parts of the same scene on different days, and most viewers would not detect that the extras (background actors) had changed clothes or appearance. Psychologists call this failure to notice such differences

Answer: Change blindness

Explanation: Change blindness occurs when an individual is blind to changes occurring to objects with which they are actively engaged. This usually occur due to perception of vision which occurs when a stimulus undergoes a change without this being noticed by its observer.