In previous articles, I covered sensations, perceptions, attention, and memory. Through our sensory organs, we receive information about the world, and using our memory, we store and retrieve that information. In this article, I will explain the next step: interpreting received and stored information.
In our day-to-day life, we often say “I think” and frequently hear terms like analytical thinking, abstract thinking, critical thinking, creative thinking, and so on. But have you ever thought about what thinking actually is? The Cambridge Dictionary defines thinking as the activity of using your mind to consider something. Not a very helpful explanation, is it?
In my opinion, thinking is the process of establishing associations between different facts or pieces of information. For example, imagine that someone told you that you have new neighbors. You haven’t met them yet, but for several consecutive days, from your window, you see a new child on the playground and a young woman looking after him. By connecting the information you heard earlier with what you see now, you may conclude that these must be your new neighbors. The next day, you see the same child, but now it is not a woman, but a young man looking after him. Connecting this new piece of information to previously analyzed details, you may now conclude that the young woman you saw yesterday and the young man you see today must be related, perhaps they are husband and wife, and this is their child. Although you have never seen the man and woman together, you can establish a relationship between them through the common denominator — the same child. This example illustrates the thinking process — how we establish relationships or associations between different facts.
The outcome of thinking is called a conclusion. Importantly, there may be several possible conclusions. In our example, the young man could be the woman’s brother who helps her look after her child when she is absent. Or maybe that young man is a single father, and the woman is a babysitter or his sister. So, there may be several explanations, but normally, we choose the most logical, or in other words, the most plausible, explanation when drawing a conclusion.
Now let’s move on to the pathology of thinking. The pathology of thinking can be divided into two major groups: disorders of HOW we think and disorders of WHAT we think. Disorders of HOW we think are called thought process impairments, whereas disorders of WHAT we think are called thought content impairments.
Let’s begin with the pathology of the thought process. The process of thinking can be impaired in many ways. First, the speed of thinking may be abnormal. It can be accelerated or decelerated. Accelerated thinking is when a person jumps to conclusions too quickly, making conclusions superficial and prone to establishing wrong associations between facts. This symptom is often observed in manic disorder. Their speech becomes very fast-paced, and they jump from one idea to the next without finishing the previous one, which sometimes makes it difficult to understand what they mean. They draw conclusions and make serious decisions without spending enough time carefully considering the possible outcomes of their decisions. They often overestimate their abilities and underestimate the risks. That’s accelerated thinking in manic disorder.
The opposite of that is decelerated thinking — when it takes a lot of time, and it becomes very difficult to make a decision, even in simple everyday tasks. This symptom is characteristic of people with depression. Depressed people tend to speak and think very slowly, with long pauses between sentences. It takes longer for them to draw a conclusion. They hesitate and quickly become tired of thinking, leaving problems unsolved. That’s decelerated thinking in depression.
The second group of symptoms is characterized by an impaired goal-orientation of thinking. Usually, when thinking, our goal is to solve a certain problem. It could be a serious problem like deciding where to live, or a simple problem like deciding what to wear. In some mental disorders, the goal orientation of thinking may be disturbed. For example, if you ask a person a question, answering that question becomes their goal. However, when trying to answer, the person may go far off topic, losing track of the initial question. This symptom is called tangential thinking.
Another symptom is called circumstantial thinking. In this type of thinking, a person has trouble separating relevant from irrelevant information. In these irrelevant details, the initial goal of thinking may also be lost.
The next symptom of impaired goal orientation is called autistic thinking, which is characterized by a tendency to be preoccupied with impractical ideas disconnected from real life. For example, someone might spend a lot of time thinking about inventing a new language, even though they are not a scientist or linguist. Tangential, circumstantial, and autistic thinking describe impairments in goal orientation.
The third category in thought process pathology describes an impaired logical structure of thinking. The word “logical” here is somewhat synonymous with “most probable.” As I mentioned previously, when we interpret something, we usually have several possible explanations, and when drawing a conclusion, we typically choose the most probable explanation. This is called logical thinking.
In some disorders, for example, schizophrenia, the logical structure of thinking may be impaired. One such symptom is derailed thinking — when a person’s ideas are strange and difficult to understand due to a lack of logical connections between them. For example, if you ask them, “How are you feeling today?”, they might answer, “I’m feeling good because a rectangle has four angles.” That’s strange logic, isn’t it?
In more severe cases of derailed thinking, the speech may be grammatically correct but have no logical meaning. For example, a person may say, “Last century, I was traveling on the spoon of oil through the quantum field of the Alexandrian library inside a bleached hair of California in China.” As you can see, the words are connected correctly, but there is no meaning in the sentence.
In the most severe cases, the logical structure of thinking may be so impaired that even the grammatical order of words becomes incorrect. For example, a patient might say, “Yes! Low over the sun, losing should cook purple strongly so not.” This symptom is called incoherent thinking or word salad. It may be observed in people with schizophrenia, but also in those with dementia, or after brain damage due to a stroke or head injury.
Finally, there is a subtle symptom called paralogical thinking, characterized by an impaired discrimination between primary and secondary features, which leads to strange conclusions, loose associations, and odd behavior. To demonstrate paralogical thinking, let’s do a quick test. Here are a book, a pen, a mobile phone, a ruler, an eraser, and a notebook. The task is to exclude one item that does not match the others. Which one should we exclude? You may pause and carefully think about that.
The most logical answer would be to exclude the phone, because it is an electronic communication device, while the book, pen, ruler, eraser, and notebook are school supplies. This conclusion is based on the analysis of the main features of the items—namely their functions. However, a person with paralogical thinking might exclude, for example, the pen, because all the other items have rectangular shapes, while the pen is cylindrical. Although it is true that only the pen has a cylindrical shape and there is some logic to such a conclusion, the shape is not the main feature of these items. That is why such thinking is called paralogical. The prefix “para” in this word means “next to” or “nearby.” So, it is close to logical, but not quite.
Paralogical thinking is often observed in people with schizophrenia. But don’t worry if you also excluded the pen. Paralogical thinking can be observed in healthy individuals too. In fact, it has been linked with creativity and the ability to find non-standard solutions in challenging situations. As mentioned in the previous video, there is no clear-cut border between normal and pathological thinking. It all depends on the degree. If, for example, you can think logically but can also switch to a paralogical style of thinking when conventional logical thinking does not help you find a solution, then it is not pathological, but advantageous. It may be considered pathological if paralogical thinking is your only way of thinking. In such cases, it can impair the quality of your decisions.
Similarly, all disturbances of thinking we have covered so far can also be observed in healthy people. For example, some people think and talk faster than others, some people are more circumstantial, and some have more autistic traits than others. It all depends on the degree of expression of the trait. If it exceeds a certain degree, it becomes pathological. Usually, we may start suspecting a pathology if that trait significantly interferes with social or professional functions.
Now, let’s move on to disorders of thought content. There are three main symptoms in this category: delusions, obsessive thoughts, and overvalued ideas.
Let’s start with delusions. It would be useful first to remind you of the definition of thinking. Remember that we defined it as the process of establishing relationships between different facts. We also mentioned that the outcome of thinking is called a conclusion. In other words, during the thinking process, we are trying to figure out whether certain events or facts are causally related or unrelated to each other. Our conclusions can then be correct or incorrect; the latter is also called a mistake. Mistakes are normal. We all make them from time to time. However, an important feature of healthy thinking is the ability to acknowledge our mistakes, understand that we may be wrong, and change our initial conclusions when there is clear evidence contradicting them. When we are unable to do that, it is called delusional thinking. So, by definition, a delusion is a false conclusion that persists despite the presence of contradictory evidence.
There are many types of delusions, but in general, they can be grouped into three categories.
The first is persecutory delusions. In this type of delusion, a person might firmly believe that someone or something is trying to harm them physically, emotionally, or reputationally. There are many forms of persecutory delusions. For example, one might believe that someone is controlling or influencing their thoughts, feelings, or actions. This is called delusions of influence. Or one might think that someone is mistreating them, spying on them, or trying to poison them. Another example is a delusion of infidelity, when a person has a firm but unfounded belief that their spouse or partner is being unfaithful.
The second category is grandiose delusions. These are characterized by firm beliefs that one has more power, knowledge, wealth, or other special traits and abilities than one actually has. For example, one might think that they have made an important scientific discovery, that they are of royal descent, or that a celebrity is in love with them.
The third category is self-deprecating or depressive delusions. These delusions are the opposite of grandiose delusions. People with self-deprecating delusions might believe that they are guilty of something or have an incurable disease. In severe cases, they might even believe that they are already dead.
Delusions can also be divided into primary and secondary delusions. Primary delusions are also called interpretative delusions. They result from incorrect interpretations of events and are characterized by an elaborate system of facts and evidence that supports the delusion. Sometimes, the interpretation may sound very plausible, making it difficult for a psychiatrist to decide whether it is true or false. It is especially difficult to diagnose so-called minor delusions, such as delusions of infidelity or theft, simply because infidelity and theft can be real. Even less probable persecutory ideas, such as being spied on, can sometimes be true. For example, the famous American writer Ernest Hemingway, before committing suicide, started expressing ideas that he was under FBI surveillance. Psychiatrists thought that these ideas were delusional, and he was eventually treated in a psychiatric hospital, not only for his delusions but also for severe depression. However, years later, the FBI admitted that they had indeed been spying on Hemingway. This is an example of how difficult it can be to separate true from delusional ideas.
Secondary delusions are easier to spot. As the name suggests, they are secondary to other psychopathology, such as hallucinations. For example, if a person has started experiencing auditory hallucinations telling them that the FBI is spying on them, they may then express persecutory delusions, believing those hallucinations. That’s secondary delusions. They are secondary to hallucinations.
Another type of thought content impairment is called an overvalued idea. As the name suggests, some ideas may have special emotional value for a person. These ideas are usually understandable when you consider a person’s past experiences and life history. For example, fidelity may become an overvalued idea for someone who has experienced infidelity in the past. They might become very jealous and restrictive in a current relationship. Unlike the delusion of infidelity, a person with an overvalued idea of infidelity does not accuse their spouse or partner of being unfaithful, but they are very suspicious and sensitive to situations that increase the possibility of infidelity. Importantly, overvalued ideas are ego-syntonic, meaning they don’t seem unnatural or pathological to the person. Therefore, people with overvalued ideas do not wish to correct these ideas, and it is difficult to prove them wrong. In some cases, overvalued ideas may later transform into delusions—unfounded false beliefs.
The next symptom is called obsessive thoughts. Obsessive ideas are ego-dystonic, meaning people who have obsessive thoughts do not like these ideas but cannot stop thinking about them. For example, someone might not be able to stop thinking about germs and dirt. Because of these thoughts, they might constantly wash their hands, clean their home, refuse to leave the house, or avoid public places and transport. They might understand that these fears are unfounded, that germs and dirt are not always dangerous, but they cannot stop ruminating and worrying about them. Such obsessions may cause significant suffering, negatively impact the quality of life, and interfere with professional and social functions.
And that’s it! We have covered the most important aspects of thinking and its pathology. Here are the main key points I wanted to explain:
• Thinking is a process of establishing relationships between different pieces of information. However, establishing the absence of relationships is just as important.
• When interpreting information, we may have several possible explanations. Healthy thinking is characterized by the ability to estimate plausibility, choose the most plausible explanation, and discard the less plausible ones.
• Another important feature of healthy thinking is the ability to change your opinion when there is strong evidence suggesting that the initial conclusion was wrong.
Of course, there is much more that can be discussed, but we will return to this topic many times later.