In one of my favourite paintings, “The School of Athens,” the most famous Greek philosophers are represented by Raphael. In the centre of the scene we can see Plato pointing to the ceiling and Aristotle pointing to the floor. Rationalism vs. Empiricism. Ideas or Facts. In psychology, Mind or Brain. In the eighteenth century, German philosopher Immanuel Kant dialectically synthesized the views of Descartes and Locke (Rationalism and Empiricism). Kant argued that both rationalism and empiricism have their place. Both must work together in the quest for truth. Most psychologists today accept Kant’s synthesis. In fact, research in Psychology follows the Scientific Method where ideas-hypothesis and facts-data play together. Now my question is, can we conciliate this Mind-Brain debate in the context of the current cognitive psychology?
Cognitive psychology and behaviour
Cognitive psychology assumes that our thinking is responsible for our behaviour. In the previous psychological theory, behaviourism (Watson, 1919), human behaviour (the response) is always understood in terms of the situation that evokes this response (stimulus)- there´s nothing in between. We feel happy because we are celebrating our birthday. However, cognitive psychology defends the idea that the stimulus itself is not enough to explain human behaviour. In other words, to understand humans, we need to study their minds. Cognitive psychology, hence, is the study of how people perceive, learn, remember, and think about information (Stenberg & Stenberg, 2012).
Following this perspective, authors of the cognitive tradition study the main psychological processes which are: perception, attention, memory, reasoning and language. From the beginning of cognitive psychology in the 50’s, psychologists have studied these processes in an effort to understand how humans approach our reality. In this sense, for example, the study of human memory sheds light on how people remember some experiences and forget others.
Recently, cognitive psychology has been strongly influenced by some advances made in the field of Neuroscience. The birth of Cognitive Neuroscience is, in words of Gazzaniga, the effort to relate the psychological processes to the brain activity (Gazzaniga, 2018).
Cognitive Neuroscience techniques
The study of the correlation between the nervous system and our cognition is possible thanks to the development of techniques that have allowed cognitive neuroscience to achieve this objective. The most well-known techniques are event-related potential (ERP) and Functional Magnetic Resonance Image (fMRI). Through the application of these techniques, researchers aim to understand what happens in our brain while we are doing specific tasks related to perception, attention, memory, reasoning or language, which are the main correlations of cognitive processing.
Event Related Potential (ERP) is used to study the electrical activity in our cerebral cortex while we are doing a specific task. The antecedent of the ERP is the EEG, which is a technique that allows us to study brain activity in a period of time. In ERP we coordinate this EEG record with specific events. A computer will mark the EEG recording every time the participant performs the specific task that we want to study. That way, we can see what happens specifically in our brain when we are doing this specific task. For example, in a classical study of memory and ERP, participants must retrieve words that they previously learned and as they do so, the electrical activity in the cortex related to this task is recorded. We can use this technique with a broad range of participants because of its non-invasive character; from babies to older people. The main advantage of this technique is temporal resolution, which means that ERPs allow us to observe the cortex activity at the same time the participant is doing the task, without delay. For instance, if the participant is trying to remember a specific word previously learned, we can observe the electrical activity of the cortex simultaneously. The principal drawback of ERP is that we can only register activity related to the cortex- it is not possible to directly see what happens in subcortical structures like the hippocampus.
Another technique is the fMRI. The antecedent of the fMRI is the MRI. The main purpose of the MRI is to take a very detailed image of the brain. The fMRI allows us to observe in this detailed image the activity of the brain. These changes in our brain activity are also correlated with cognitive processes. Following the previous example of a typical memory task, we can ask a person to recall some words previously learned and observe with the fMRI what occurs in the brain during this activity.
The main assumption of the fMRI is based on the idea that when a specific area of our brain is implicated to do a task, this area will demand more oxygen in our bloodstream. The fMRI will detect which areas have consumed this oxygen. In an fMRI experiment, the participant will lie down in the scanner and be asked to perform a specific task inside the scanner. Usually the researchers present the experimental task on a computer and participants see the computer through a mirror located in the scanner.
fMRI allows us to observe the activity of the entire brain, with a very precise quality, including subcortical structures. The main disadvantage of this technique is related to temporal resolution, as I previously explained. In contrast to the ERP, here, we cannot simultaneously observe the activity of the cortex while the participant is doing the task. With the fMRI, we can only observe the brain activity after the completion of the task. We’re talking about a very brief delay of mere seconds.
After analysing these techniques, we can see how modern cognitive psychology demonstrates the relationship between cognitive processes and the brain, thanks to cognitive neuroscience. At this point, it is worthy of note that this relationship between cognition and neuroscience is able to conciliate the brain vs. mind debate that we, as psychologists, have inherited from philosophy. Cognitive psychology is the science in charge of understanding the main processes (mind) that help us to understand our world and neuroscience studies how the brain correlates these processes.
Gazzaniga, M.S.; Ivri R.B.; Mangun G.R. (2018). Cognitive Neuroscience: The Biology of the Mind. New York. USA. W. W. Norton & Company.
Sternberg, R. J., & Sternberg, K. (2012). Cognitive Psychology. Belmont. USA. Wadsworth.
Watson, J. B. (1919). Psychology from the standpoint of a behaviorist. Philadelphia. USA. Lippincott.