How did researchers study internal mental processes using measurable behavior?

During the mid-20th century, researchers shifted away from the behaviorist view that the mind was inaccessible, instead developing experimental methods to infer internal mental processes from measurable behavior. Rather than relying solely on observable stimuli and responses, cognitive scientists began treating the mind as a system that acquires, organizes, stores, and uses information.1

Researchers study these internal processes by analyzing observable data, such as:

• Reaction time: By measuring how long it takes to make a decision or respond to a stimulus, researchers can isolate the time required for specific mental operations.12
• Accuracy: Tracking the precision of memory recall or task performance provides insight into how information is processed and stored.1
• Mathematical modeling: Investigators use reaction-time data to break down complex tasks into constituent mental processes, assuming these processes occur either serially or in parallel.2
• Computer modeling: By constructing algorithms that mimic proposed mental functions, researchers test hypotheses; if the computer's output matches human performance, the underlying theory is supported.32

These approaches allow scientists to investigate complex abilities like memory, attention, and problem-solving by making measurable predictions about how the mind functions.14