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Scope of cognitive psychology

cognitive psychology is generally understood to be a part of psychology, but specialises in studying the internal mental process of perception, memory, and decision-making. In the book “principles of cognitive psychology”, it is described as:

“a study of the main internal psychological processes that are involved in making sense of the environment and deciding what action might be appropriate”.

Challenges of studying cognitive psychology

cognitive psychology is a difficult subject to study, not because it is intellectually challenging, but the subject of study is invisible to human eyes. In addition, the processes involved within our brain are not always clear.

For example, there was a time when it was believed that thinking process works in a sequential manner. In other words, it was believed that we process information one at a time and those processes never happen in parallel. This idea however cannot explain how human can multitask. This has now been replaced with the theory of parallel processing.

Similarly, it was believed that stimulus always generate a response. According to this theory, a piece of reading material can be a form of stimulus, which in turn triggers some response or action that can be measured. This conceptual framework is called top-down processing. However, many experiments have been designed and shown and that people miss read statements because of the brain is not reacting purely and simply to the stimulus. To the contrary, we have our own perception and expectation, which may interfere with the way we process the stimulus information. We were given an example of a statement which says, “Paris in the the spring”. It has been shown through similar experiments with the repeatable results and observations that many people read the statement as, “Paris in the spring”. The fact that the word of “the” is repeated is often missed out. This is an example of bottom-up processing of the brain. In other words, the brain is not just reacting to the stimulus as an independent trigger of response, but perception and expectation has a role to play as well.

Overall, there is a strong message in these introductory chapters that the main challenge in cognitive psychology is to identify the exact process used by the brain. In engineering terms, one can describe the situation as a study of a black box, where inputs and outputs can be controlled measured but opening up the blackbox is prohibited. Or perhaps in mathematical terms, one can describe the situation as a study of a function box, where again the inputs and outputs can be measured but the precise mathematical function of the box is not known. In both analogies, we can see multiple possibilities and theories can be developed for any given set of inputs and outputs. Therefore, we can never be sure that the proposed process represents the way the brain functions. At best, we arrive at a conceptual model that helps our understanding.

Four main research methods in cognitive psychology

Given that we’re studying the blackbox that we may not open, the next logical question is how does one study it? It would appear in the area of cognitive psychology, there are four main ways of studying cognition: A) by experiment, B) by comparing brain-damaged patients, C) by developing computational models, and D) by brain scans.

Experiment

out of all the methods, the experimental methods is the easiest to understand. There are usually conducted in a controlled environment, which lends itself to scientific studies of data. However this type of approaches are commonly challenged for two reasons: A) as explained before, these can only provide indirect evidence about the internal processes involved, and B) given the context of a controlled environment, which is highly artificial, it is often difficult to justify or believe that the subjects will behave in an identical manner in real life.

Comparison

the comparison method is an interesting one. Essentially, cognitive psychologists look for brain-damaged patients and compare what they can or cannot do with other patients. For example, if they have patients who can speak very well but cannot hear, they can then conclude that the processes involved in speaking are independent of those for hearing. This method is most conclusive when patients with opposite skills matrix occur. For instance, if a group of patients can do task A very well but not task B, and another group of patients can do task B very well but not task A, we can then conclude with confidence that the processes involved in task A or B are totally independent of each other.

This method has its own limitations though. For example, where patients can perform part of the task, can we still make a conclusion? Also, this issue is that there is only one or two of the brain that contributes to a certain function. However, more often than not, unless the task is exceptionally simple, different functions of the brain will be invoked. Take matching shapes as an example. Young children are often given toys which required them to recognise different shapes. This is a very simple task in its own right. However, it involves long-term memory (remembering the instruction given), short-term memory (what their eyes have just seen), decision-making, and motor skills. It is often very difficult to isolate these processes as totally independent of each other.

computational models

computational models are closely akin to a branch of computer science called artificial intelligence. Feeding by the information gathered through previous methods, programmers builds computational models to represent cognitive processes. Although cannot guarantee to be representative of the exact cognitive process involved, it does allow a systematic way of investigating the processes. Usually, the programmers involved use what is known as the connection networks, where there are input links, processing units, and output links. Unlike computer networks where there is specific location for memories, connection networks in psychology have memories distributed over the network.

brain scans

finally, the last approach makes use of a modern technology in brain scanning to establish where and when cognitive processes happen within the brain. This method of study has been very useful in areas where processors function in discreet ways. However, it has been less successful in higher order cognitive functions such as reasoning and decision-making or where cognitive functions and processes do overlap.

Reflection

it has been very interesting to read through the introductory chapters of my first book in cognitive psychology. I have found the definition and scope of cognitive psychology very helpful and the chapters discussing the four major approaches informative. I was very surprised to see how brain-damaged patients can help in research. And of course technological advances has made it possible to probe into the blackbox itself.

Moving On

This book then continues to discuss cognitive psychology in four main study areas: A) three chapters on recognition and perception, B) two chapters on memory management, C) two chapters on language comprehension and production, and D) three chapters on problem solving and decision making. I will be updating my blog as I read and reflect on the material as I consider these areas one at a time.