Answer:
Introspection
Step-by-step explanation:
Introspection is the term that refers to a subject's ability to observe internal and personal factors from within their own thoughts, memories, feelings, observations, emotions and any other type of content related to their own thinking, becoming aware of what effects these elements have in your own organism.
An example of this can be seen in the question, where a researcher presents his participant with a series of flashing lights at different intervals. After each presentation of a light, he asks the participant to fully describe his internal experiences.