How can emotions, moods and feelings be measured? - Chapter 2

How can we define emotions and moods? 

This chapter covers a brief history of scientific research on affect, to determine what is generally meant by emotions, feelings, and moods. This mainly concerns the different methods used to measure these different aspects of affect.

What is the definition of emotion?

There is no clear definition of emotion. However, many theories agree that each emotion consists of a number of different components: subjective report, physiological response, cognitive appraisal, and so on. Each component fulfills a certain function in dealing with an emotional situation.

A frequently asked question is whether cognitive appraisals are a cause of emotion or rather a component of it. The component process model states that appraisals are important components and that emotions are only experienced if multiple subsystems are coordinated to cause an adaptive response to an event that is considered significant for the well-being of a person. From this perspective, emotion is seen as an occurrence of interrelated, synchronized changes in the state of the subsystems, in response to the appraisal of an internal or external stimulus perception that is relevant to the organism.

Recognizing a cognitive component in emotion is very controversial because many researchers assume that emotion and cognition are completely separate - but interacting - systems. Izard, for example, states that a distinction must be made between an emotion and an emotion scheme. An emotion is only a response to an event, and in his opinion, does not require appraisal, but an emotion scheme integrates the emotional response with complex cognitive appraisals.

The component process model states that all five components (cognitive, physical, tendency to act, expression and feelings) operate separately most of the time. To be able to form an emotion, these components must be coordinated and synchronized for a short time, and this process is driven by evaluation processes.

Emotions can be understood as coordinated responses to a number of different objects and situations, which are called emotionally-competent stimuli. The question is whether any stimulus that is appraised is emotionally competent, or whether there are stimuli that are previously judged to be significant by their important biological or social influence. One possibility is that stimuli that provoke emotions can be divided into the categories of rewards and punishments. This simplified distribution of emotionally-competent stimuli is an elegant way to describe the cause of emotions, but does not properly reflect the complexity of the stimuli and evaluations.

Some argue that emotions are best understood as action tendencies that prepare an organism to act in a certain way. From an evolutionary perspective, emotions can be seen as the regulators of behavior intended to help us deal with the demands of evolution.

Emotions have three unique characteristics:

1. Emotions are embodied, they are clearly recognizable by behavioral patterns, facial expression and excitement
2. Emotions are less sensitive to our intentions than other psychological states
3. Emotions are less encapsulated than other psychological states, which becomes clear in their global effects.

What is a mood?

The term mood describes a wide range of feelings. Moods are generally seen as evaluations of our overall well-being. They can be seen as states that reflect one's general position in life. This explains why a situation can sometimes cause a change in emotion, but not necessarily in the mood. Moods are actually emotions that have been spread over a longer period. According to Damasio, this means that the feelings and physical changes associated with the emotion are also spread over time.

How can moods and emotions be distinguished? 

Emotions are short-lived, arise in response to specific events and are relatively intense with the additional physiological excitement. This confirms that it is an important function of emotions to enable adaptation to important events. Opposite of emotions are moods, which are characterized as of longer duration and less intense. The physiological excitement is more diffuse and moods have more influence on cognitions (instead of actions). Moods can arise due to the influence of emotions.

Emotions are related to specific objects or events, while moods lack this clear focus. This can be explained by the fact that a mood is also seen as an emotion without the cognitive evaluation of the characteristics of a stimulus. Therefore, to cause a mood, there is no direct stimulus required. 

Another theory states that a mood is always present as a kind of affective background for our daily lives. It colors our cognitive processes, while emotions can be seen as disturbances in this background. So, emotions cause more short-term changes in the way we see the world.

How do we measure affect?

There is a wide range of measurement instruments for both emotions and moods. Some focus on subjective self-report: asking someone how they feel. Others focus on physiological and behavioral indicators, while others directly measure brain activity. A challenge is to generate moods and emotions in a laboratory setting. This is possible, for example, with the mood induction procedure, a technique whereby people read a list of statements about themselves that are either sad or happy. This is an effective technique, but it is not always clear whether it is a mood or an emotion that is being generated. To create real emotions, emotionally competent stimuli are often used, such as an angry face. More cognitive tasks (for example, remembering a traumatic event) tend to trigger a mood.

How do we measure emotions?

Emotions are often accompanied by a feeling. These conscious feelings can only be reported firsthand, so this self-report cannot be replaced by all other components that we measure emotion. However, we cannot get a complete picture of emotions without taking physiological and behavioral measurements.

How are the behavioral aspects of emotions measured?

A form of behavior that is clearly linked to emotion is facial expression. Other behaviors include screaming when afraid or shouting loudly when anger. However, a problem for researchers is that people are good at suppressing these behaviors. For example, a sad person can do his best to appear cheerful to his environment. In addition, it differs per culture whether it is appropriate to show a certain emotion. In Japan, for example, it is inappropriate to show anger or aggression.

Observation techniques are used to observe children or animals in their natural environment, allowing different behavioral responses to be viewed in relation to the presence of a particular stimulus. Many animal species show a series of behaviors that are indicative of emotional state, especially anxiety.

Charles Darwin was one of the first who studied facial expressions. His conclusion was that similar facial expressions throughout the world indicated similar emotions. Ekman found the same with his research with an isolated group of people from Papua New Guinea who were able to divert emotions from the facial expressions of white Americans. This indicates that facial expressions are universal rather than culturally determined.

How are the physiological aspects of emotions measured?

In addition to behavioral responses, emotions are also associated with a range of physiological responses, such as an increased heartbeat, sweaty hands, or the release of large amounts of hormones. In the event of an extreme fear reaction, blood is carried away from slow processes such as digestion and supplied to muscles and the brain, to enable a rapid fight or flight response. All these physiological changes are controlled by the autonomic nervous system (ANS). This system ensures the function regulation of the internal environment of the body and consists of two parts. The sympathetic nervous system controls the effects of excitement, the parasympathetic nervous system controls the effects that occur when we are at rest. General techniques used in measuring physiological responses in emotion science are skin conductance response (SCR), measuring heart rate (HR), measuring blood pressure (BP), measuring cortisol level, electromyography (EMG) and measuring respiration rate.

How are the neural aspects of emotions measured?

Despite the fact that certain structures that are part of the limbic system (cingulate cortex, hippocampus, thalamus, hypothalamus, amygdala) are important for emotions, recent research shows that different brain circuits control different aspects of emotions. In addition, many of these brain parts are involved in other functions as well as emotion.

Much of what we know about the brain and emotion comes from animal studies, in which specific parts of the brain were removed and the changes that occurred were then examined. Another common technique is single cell recording. An electrode is introduced deep into the brain that can directly measure the activity of a single neuron or a small group of neurons.

However, most progress in neural basis research has been made through the development of functional imaging of the brain. Different techniques are positron emission tomography (PET), functional magnetic resonance imaging (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG). PET and fMRI both work by measuring changes in blood flow in different parts of the brain. More active parts use more oxygen and therefore receive more blood. EEG works by measuring electrical activity in the brain. From this we can obtain a measurement called event-related potential (ERP), a specific electrical signal that occurs in response to a specific stimulus. MEG uses a device that can measure the magnetic field that is created by the electrical activity in the brain.

How are the subjective aspects of emotions measured?

Many people find that the subjective component of emotions is the most important, because how an emotion feels is often the most salient to us. Introspection ('looking into our own minds') has long been an important method for investigating emotions. Nowadays, it is almost no longer used because it appears not to be a reliable method. People often do not have a good idea of ​​the causes of their own behavior. We have a natural tendency to look for a reasonable explanation for our behavior, even though this explanation is often wrong. In addition, we also do not have a good picture of the causes of our emotions; stimuli that we unconsciously receive can still influence our behavior.

Backward masking is a technique in which a target stimulus can be seen very briefly, after which a masking stimulus is shown almost immediately. The subject is not aware that he has seen the target stimulus, but when this is a frightening image, a physical fear reaction nevertheless arises. This proves that an emotional response can occur even when there is no conscious recognition of the stimulus. The mere exposure effect is the finding that we tend to like stimuli that have been repeatedly presented even though we may not be aware of the repeated presentation.

It is important to develop methods for measuring subjective experiences. Keeping a diary is an example of a promising technique, but it is not often used. What is often used at the moment is questionnaires, developed to give people the opportunity to report their subjective state of feeling.

What are questionnaire-based measurements of emotion?

With a questionnaire, it is important to distinguish between state and trait aspects of emotion. This means that it is important to consider carefully in advance whether the feelings will be asked when the questions are asked (state) or more general feelings (trait). State emotions often have a wider range of intensity than trait emotions and refer to a specific event of limited duration. If someone possesses a certain trait emotion, this means that he or she is inclined to experience that emotion more often in different situations.

How are the cognitive aspects of emotions measured?

When we talk about the cognitive aspects of emotions, we mean the fundamental biases in perception, attention and memory. The most commonly used measurement is the simple reaction time, which indicates very precisely how quickly someone can give a motor or verbal response to a particular stimulus. It appears that the processing of negatively charged words (such as 'cancer' or 'failure') is faster than positively charged words (such as 'vacation' or 'price').

In addition to response time, memory is also used as a measurable concept. For example, when people see a number of positively charged and negatively charged words and we later ask them to repeat as many of these words as possible, it appears that people generally remember the negative words better.

In summary, for the measurement of emotions, the behavioral, physiological, and neural components are mainly considered. There is some controversy about whether the cognitive factors (evaluations and tendencies) are also components of emotions, or causes of emotions. The subjective aspects are also important, although there is disagreement about the quality of the existing measurements.

How are moods measured?

The terms emotions and moods are often used interchangeably, this lack of a clear dividing line may have had an inhibiting effect on the development of research into the two phenomena. Most of the above measurements can be used for both emotions and moods. It is therefore not always clear which of the two is being measured precisely.

How are the physiological and neural aspects of moods measured?

The before mentioned brain imaging techniques EEG, PET, fMRI and the physiological measurements of heart rate and cortisol release can also be used to study moods. This even has advantages; because moods are longer, there is more time to view the effects. However, one problem is that most of what we know about moods comes from the investigation of mood disorders such as depression.

This research shows that a reduced presence of neurotransmitters such as dopamine and serotonin in the body plays an important role in the development of depression. According to the monoamine hypothesis or mood disorders, a depressive mood is related to a reduced presence of monoamine neurotransmitters (in particular serotonin and noradrenaline) in the brain. Conversely, an increased presence of these transmitters in the brain leads to a positive mood. The hypothalamic-pituitary-adrenal (HPA) axis is responsible for the release of the neurotransmitters (especially cortisol) that deal with stress. An overactive HPA axis is associated with anxiety disorders and mood disorders, which often occur together.

An interesting fact is that the HPA axis is regulated by the amygdala and the hippocampus, both of which are of great importance for affect. Activity in the amygdala (often related to anxiety) stimulates the HPA axis, while activity in the hippocampus suppresses the HPA axis. The hippocampus contains glucocorticoid receptors that bind cortisol from the HPA axis. As a result, the hippocampus knows when the activity in the HPA axis must be suppressed. A reduction in the number of these receptors therefore explains part of the high activity of the HPA axis in depression and anxiety disorders. This reduction in receptors can be a result of neglect and abuse during childhood. This has greater consequences for mood states than for emotions.

Research into neural structures shows that emotions are mainly mediated by, among others, the amygdala and the anterior cingulate cortex (ACC). These structures work closely with motor circuits and can therefore cause action-oriented responses triggered by perception. Moods, on the other hand, are associated with a more refined cognitive-oriented response triggered by complex cognitive processes. These are mainly located in the prefrontal cortex (PFC).

How are the cognitive aspects of moods measured?

The most commonly used research strategy in this field is to measure the effects of mood on memory or social judgments. This is done by causing a certain mood, after which a memory task must be done in which negatively or positively charged words must be remembered. These must be repeated later, when the person is back in a neutral mood. This type of research has found mood congruent encoding, which means that people in a certain mood are more inclined to remember information that is consistent with that mood. In other words, the current mood also determines whether people tend to make a positive or negative prediction about their future. Mood determined by the weather can affect our sense of well-being and our satisfaction with life. When people are in a good mood, they are quicker to identify happy words, but when they are in a bad mood, they are more likely to identify sad words.

How do we experience emotions and moods?

An important component of emotions and moods is the conscious experience of affect; the states of feeling that are such essential ingredients of human emotion. When we talk about emotions in everyday life, we actually always talk about how we felt in these situations. Some even argue that affective responses (emotions and moods) and feelings are so close together that it makes no sense to distinguish them from each other. However, Damasio does not agree. According to him, feelings are the mental representation of the physiological changes that occur during an emotion, or during a mood.

What and how do we feel?

It is not so long ago that emotions and feelings were first treated as separate concepts in the research into affect. The fact that this did not happen before could be due to the fact that researchers have to use the unreliable introspective techniques. There is increasing evidence that emotions and moods are only felt in consciousness as states of either pleasure or displeasure. The mental representation of an emotion then indicates whether the degree of pleasure (or displeasure) is high or low. Feeling is a complex combination of information from all kinds of different systems, which represents the valence and excitement in consciousness.

Damasio came up with the first-order bodily representations: both the own body and an external object are stored as neural patterns, these are the first-order maps. Second-order maps can be formed based on changes in these maps that are related to changes in the body. These represent the relationship between the external object and the body. Second-order bodily representations mean that the neural patterns from the second-order maps form mental images that describe the relationship; these are the feelings according to Damasio. They help to provide integrated feedback, which in turn can be adjusted by continuous experiences. According to Damasio, feelings are therefore the awareness of biological functions and this awareness allows us to distinguish the different emotions. Feelings therefore depend on consciousness.

How are the neural and physiological aspects of feelings measured?

The difficulty in discovering the neural basis of feelings is that feelings are by definition private mental states. In addition, feelings only arise after emotions, making it difficult to separate the functional neuroanatomy of emotions from that of feelings. Many have tried to explore feelings by letting people recall memories of emotionally charged moments. Unfortunately, in virtually none of these studies, a significant difference was found between brain activity with different feelings.

When the activity was compared with a baseline, it was found that in all different moods there was an increased activity in the punching hypothalamus. This finding supports the theory that feelings are associated with changes in autonomic nerve functions that are controlled by the same parts of the brain.