Cognitive psychology is the branch of psychology that deals with the scientific investigation of the mind.

How does one study the human mind?

The 'mind' can be viewed in different ways. This chapter defines mind, describes how the mind has been viewed over time, and how researchers have studied the mind.

What is the mind?

The mind is a system that creates mental representations of the world and controls mental functions. Examples of such mental functions are perception, attention, memory, emotions, language, decision making, thinking and reasoning. The mental processes involved in mental functions are called cognition.

It is important to realize that cognition does not only encompass the "higher" mental functions and that many of the processes involved occur outside of conscious control.

Which studies in cognitive psychology were conducted first?

Scientists coined the term "cognitive psychology" in 1967, but the following studies can be qualified as cognitive psychological experiments.

Franciscus Donders, a Dutch physiologist, researched the time it took a person to make a decision in 1868. He determined this by measuring the reaction time - the time it takes for a person to respond to a presented stimulus. First he measured the simple reaction time. This is the time it takes for a person to respond to the presence or absence of a stimulus. He used a lamp for this and a participant had to press a button as soon as the lamp came on. Then he measured the choice reaction time. That is the time it takes to respond to one of two or more stimuli. Donders measured this reaction time by pressing participants on the left button when the left light came on and pressing the right button when the right light came on.

The following steps take place during the first measurement: switching on the lamp causes a mental reaction, namely the light is perceived, and this leads to a behavioral reaction (pressing the button). The time between turning on the lamp and pressing the button is the simple reaction time.

An extra step is required when measuring choice reaction time. During this task, participants also have to determine which button to press. As expected, the reaction times of the participants in the first task were shorter than in the second task. Donders reasoned that the time difference in response indicated the time it took the participants to make a decision.

Donders' experiment is important because it shows that mental reactions cannot be directly measured, but must be concluded on the basis of observed behavior. This is a principle that applies to all research in cognitive psychology.

Wilhelm Wundt founded his first laboratory in 1879. Wundt's approach was structuralism. Structuralism is an approach within psychology that explains perception as the addition of small and elementary units. These units are called sensations. Wundt made extensive use of analytic introspection. This is a technique in which trained participants describe their sensations, feelings and thoughts in response to stimuli. Structuralism was not a fruitful approach and researchers stopped using it from the beginning of the twentieth century. Still, Wundt made a significant contribution to psychology through his commitment to study behavior and the mind under controlled conditions.

In 1885, the German psychologist Hermann Ebbinghaus investigated how quickly learned information is forgotten over time. He used a quantitative method to measure this by creating a list of syllables that made no sense and learning them. After a specific amount of time (delay), he measured how long it took him to learn the list again. Relearning the list was faster than the first time he learned the list. To determine how much information was retained after a certain delay, Ebbinghaus suggested a measure: savings. Savings were calculated as follows: savings = (original time to learn the list) - (time to learn the list again after a delay). According to Ebbinghaus, the decrease in savings provides a measure of forgetting, where smaller savings means more forgetting. The savings curve is a plot in which percentage savings are plotted against time. This curve is important because it showed that memory could be quantified and that functions such as the curve could be used to describe a property of the mind.

In 1890 an American psychologist named William James wrote his famous book Principles of Psychology. In this book he describes important observations about the mind. His observations were quite accurate and covered a wide range of cognitive topics.

Why did researchers stop studying the mind?

Much of the emphasis on studying the mind has been replaced by a focus on "pure" observable behavior. This approach is called behaviorism and is strictly concerned with the investigation of stimulus-response or input-output relationships.

Around 1913, John Watson became very dissatisfied with the analytic introspection method because it produced variable results from person to person and the results were very difficult to verify. Watson therefore proposed a new approach: behaviorism. Watson wanted to limit psychology to observable behavioral data and rejected the idea of ​​going beyond these data to draw conclusions about observable mental events. Watson's ideas are closely associated with classical conditioning. This is a procedure in which coupling a neutral stimulus to a stimulus that elicits a response causes the neutral stimulus to elicit the same response. This was first studied by the Russian Ivan Pavlov. Watson showed that the principles of classical conditioning also apply to human behavior and he used the idea of ​​classical conditioning to argue that behavior can be analyzed without referring to the mind.

Twenty-five years later, B. F. Skinner introduced operant conditioning. Operant conditioning focuses on how behavior is reinforced by the presentation of positive reinforcers or by the removal of negative reinforcers.

The idea that behavior can be understood through the study of stimulus-response relationships influenced an entire generation of psychologists for about 30 years. The techniques of classical and operant conditioning have been applied in various fields, such as in education and mental health.

A common criticism of the stimulus-response theory was that it could not explain why people often responded to different aspects of the same stimulus, and that that particular aspect does not become apparent until a response is given.

One researcher who did not follow the strict line of behaviorism was Edward Tolman and later Noam Chomsky. Tolman discovered the existence of a cognitive map through his experiments. That is a mental conception of a spatial layout.

Chomsky saw language development as something that arose not through operant conditioning, but through an innate biological program that is the same for every culture. This idea caused psychologists to rethink the idea that language and other complex behaviors can only be developed through operant conditioning. They began to realize that it is necessary not only to measure observable behavior but also to examine what this behavior says about how the mind works in order to understand complex cognitive behavior.

What is the Cognitive Revolution?

The 1950s are seen as the beginning of the cognitive revolution. The cognitive revolution is a shift in psychology from behaviorism to an approach where the primary focus is on understanding the workings of the mind.

In the 1950s, some psychologists suggested using an information-processing approach to study the mind. This is an approach that follows sequences of mental operations involved in cognition. According to this approach, the functioning of the mind can be described as occurring in a number of stages. Applying the information processing approach caused psychologists to ask new questions and shape their answers in new ways.

Donald Broadbent designed a flow diagram. His scheme provided a way to visualize and analyze the workings of the mind in terms of a sequence of processing stages. This also resulted in a model that could be further studied by means of experiments.

What does modern research look like in cognitive psychology?

Modern research in cognitive psychology uses models.

What is the role of models in cognitive psychology?

Models are representations of structures or processes that help us visualize or explain the structure or process. Two types of models are discussed in the book:

• Structural models: represent the structures in the brain involved in specific functions.

• Process models: illustrate how a process works; often by means of boxes representing a specific process and arrows indicating connections between processes.

Structural models are representations of a physical structure. Structures can also be represented by schemas that do not resemble the structure itself, but instead indicate how different areas of the brain are connected.

Today, cognitive psychologists are increasingly called upon to help solve problems in society, such as road safety issues.

Ebbinghaus showed that repeated presentation of information facilitates learning and improves memory. If repeated presentation of information is spread over time (spacing), learning will slow down, but it will also lead to a more sustainable retention. In the meantime, it's a good idea to learn something else. Research shows that mixing learning from different subjects within the same domain will not impair performance, but improve it. This mixing is called interleaving.

Retrieval based learning is learning based on the retrieval of previously stored information. Research shows that retrieving information from memory increases the chance that the same information can be retrieved again in the near future.