Pleasure is not just about experiencing an enjoyable moment. It also involves anticipation – a connection between one's present and future selves.
Schizophrenia is one of the most widely misunderstood of human maladies. The truth of the illness is far different from popular caricatures of a sufferer muttering incoherently or lashing out violently. People with schizophrenia are, in fact, not more likely to be violent than people without schizophrenia. About one per cent of the worldwide population has schizophrenia, affecting men and women, rich and poor, and people of all races and cultures. It can be treated with medication and psychosocial treatments, though the treatments don't work well for every person and for every symptom. Most of all, it impacts everything that makes us human: the way one thinks, the way one behaves, and the way one feels – particularly the ability to experience pleasure.
Three-quarters of people with schizophrenia suffer from anhedonia: the decreased pleasure from events or activities that were once enjoyed. Friends will no longer be fun to be around, and once-tasty meals can come to taste bland. (It is also a core symptom of depression.) From a clinical perspective, anhedonia is assessed via an interview with a mental-health professional in which a person is asked about pleasure and enjoyment in various life activities such as socialising, eating, working or participating in hobbies.
In my research, I have incorporated methods, theories and measures from the field of affective science to better understand anhedonia in schizophrenia. Affective science theory and research is grounded in the notion that emotions, such as pleasure, are more fully captured and understood through comprehensive, multimethod assessment. I assess emotional responses by measuring changes in facial expression, reports of experience, brain activity and body responses when people with and without schizophrenia are engaging with emotionally salient stimuli such as films, pictures, foods or simply talking about their own lives.
Can people with schizophrenia accurately and reliably report on their feelings, given that they often have profound thinking disturbances? Yes. People with schizophrenia can use the same broad dimensions when describing their feelings as people without schizophrenia: valence, or how pleasant or unpleasant a particular emotion is; and arousal, or how highly activating or calming an emotion is. Excitement represents a high-activation pleasant emotion; serenity represents a low-activation positive emotion, and boredom reflects a low-activation unpleasant emotion. People with schizophrenia report experiencing similar (or slightly lower) amounts of pleasant emotion, compared with those without schizophrenia, in the presence of emotionally evocative stimuli and in daily life, regardless of changes in medication status.
However, pleasure is not just about experiencing an enjoyable moment. It also involves anticipation – a connection between one's present and future selves. This is a crucial distinction. Pleasure is not just about the consummatory (that is, in-the-moment) experience, but also anticipatory pleasure: the ability to both look forward to future pleasurable experiences, as well as to enjoy the anticipation of pleasure in and of itself. Schizophrenia makes this distinction clear. People with this illness are less likely to predict or anticipate that future events will be pleasurable, as well as less likely to experience pleasure in anticipation of things to come. This, in turn, makes it less likely that they will seek out pleasurable experiences at all.
Anticipating whether something in the future will be pleasurable requires myriad cognitive skills, including imagination, reflection, drawing upon past experiences, and maintaining an image or emotional state. Consider the example of deciding where to go on holiday. You might think about visiting a national park in the United States, which leads you to call forth a past vacation you took to visit Yellowstone National Park. This then prompts you to predict that your vacation will be relaxing and enjoyable, taking in the sights and the wildlife. With this prediction you actually begin to experience pleasure now – in the knowledge that you will be experiencing pleasure soon. This is anticipatory pleasure. These processes will support your motivational system such that you will make your travel reservations (approach motivation and behaviour) and, once you take your holiday, you will experience consummatory pleasure. You will savour (maintain) the pleasure from the holiday, and this experience will be remembered. And the next time you need to make a holiday choice, this memory might be called upon to restart the temporal process again.
One way that I have assessed the experience of pleasure-in-anticipation in my research is by using a self-report measure of physical/sensory anticipation experience called the Temporal Experience of Pleasure Scale. This measure includes items that assess both anticipatory and consummatory pleasure experience for different physical sensations (for example, 'When I think about eating my favourite food, I can almost taste how good it is'). People with schizophrenia score lower on the anticipatory pleasure scale compared with people without schizophrenia, but they score the same on the consummatory pleasure scale. This pattern has been found among those who are at risk for developing schizophrenia, are early in the course of the illness or have had the illness for many years, and in people with schizophrenia from different countries and cultures.
Other research approaches to studying anhedonia in schizophrenia draw heavily from neuroscience research, in part because the quest for pharmacological treatments is informed by what we know about the human brain. In particular, the neuroscience of motivation, which includes several processes and brain networks, has been used to understand anhedonia in schizophrenia. Motivation processes include a calculation of how much effort is needed to achieve a desired, pleasant outcome (reward), a plan of how to obtain that outcome, and a behavioural response to get the reward. This neuroscience approach has illuminated a number of key findings about anhedonia in schizophrenia, showing for example that people with schizophrenia have difficulties in computing the value and effort needed to obtain pleasant outcomes and exerting effort to achieve rewards.
It is essential to also measure phenomenological experience: if you want to know how someone is feeling, you need to ask them. No measure of brain activity, facial expression or bodily response is a substitute for assessing feelings. My colleagues and I have shown that people with schizophrenia can report clearly on how they feel, and assuming that people with schizophrenia cannot do so is not only incorrect, but can also perpetuate myths and misperceptions about the illness (the loopy, incoherent muttering and flailing anger). Current neuroscience research on human brain networks that support thinking, feeling and perceiving other people has demonstrated that many of the brain's same networks participate in the support of these psychologically diverse processes and functions, rendering the search for psychological process-specific networks nearly obsolete.
Anhedonia, or diminished pleasure, in schizophrenia is most apparent when it comes to anticipating future events. People with schizophrenia report expecting less pleasure from enjoyable activities, and experience less pleasure when anticipating future events, than people without schizophrenia. However, when actually doing these pleasant activities, people with and without schizophrenia report experiencing the same amount of pleasure. The example of anhedonia in schizophrenia illustrates that pleasure is not a single process. Instead, pleasure emerges from a host of interacting cognitive, affective and motivational systems, dysfunction in any one of which can lead to problems with pleasure.
Ann M. Kring
This article was originally published at Aeon and has been republished under Creative Commons.
In a study that might enable earlier diagnosis, neuroscientists find abnormal brain connections that can predict onset of psychotic episodes.
Anne Trafton | MIT News Office
November 8, 2018
Schizophrenia, a brain disorder that produces hallucinations, delusions, and cognitive impairments, usually strikes during adolescence or young adulthood. While some signs can suggest that a person is at high risk for developing the disorder, there is no way to definitively diagnose it until the first psychotic episode occurs.
MIT neuroscientists working with researchers at Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, and the Shanghai Mental Health Center have now identified a pattern of brain activity correlated with development of schizophrenia, which they say could be used as a marker to diagnose the disease earlier.
“You can consider this pattern to be a risk factor. If we use these types of brain measurements, then maybe we can predict a little bit better who will end up developing psychosis, and that may also help tailor interventions," says Guusje Collin, a visiting scientist at MIT's McGovern Institute for Brain Research and the lead author of the paper.
The study, which appears in the journal Molecular Psychiatry on Nov. 8, was performed at the Shanghai Mental Health Center. Susan Whitfield-Gabrieli, a visiting scientist at the McGovern Institute and a professor of psychology at Northeastern University, is one of the principal investigators for the study, along with Jijun Wang of the Shanghai Mental Health Center, William Stone of Beth Israel Deaconess Medical Center, the late Larry Seidman of Beth Israel Deaconess Medical Center, and Martha Shenton of Brigham and Women's Hospital.
Before they experience a psychotic episode, characterized by sudden changes in behavior and a loss of touch with reality, patients can experience milder symptoms such as disordered thinking. This kind of thinking can lead to behaviors such as jumping from topic to topic at random, or giving answers unrelated to the original question. Previous studies have shown that about 25 percent of people who experience these early symptoms go on to develop schizophrenia.
The research team performed the study at the Shanghai Mental Health Center because the huge volume of patients who visit the hospital annually gave them a large enough sample of people at high risk of developing schizophrenia.
The researchers followed 158 people between the ages of 13 and 34 who were identified as high-risk because they had experienced early symptoms. The team also included 93 control subjects, who did not have any risk factors. At the beginning of the study, the researchers used functional magnetic resonance imaging (fMRI) to measure a type of brain activity involving “resting state networks." Resting state networks consist of brain regions that preferentially connect with and communicate with each other when the brain is not performing any particular cognitive task.
“We were interested in looking at the intrinsic functional architecture of the brain to see if we could detect early aberrant brain connectivity or networks in individuals who are in the clinically high-risk phase of the disorder," Whitfield-Gabrieli says.
One year after the initial scans, 23 of the high-risk patients had experienced a psychotic episode and were diagnosed with schizophrenia. In those patients' scans, taken before their diagnosis, the researchers found a distinctive pattern of activity that was different from the healthy control subjects and the at-risk subjects who had not developed psychosis.
For example, in most people, a part of the brain known as the superior temporal gyrus, which is involved in auditory processing, is highly connected to brain regions involved in sensory perception and motor control. However, in patients who developed psychosis, the superior temporal gyrus became more connected to limbic regions, which are involved in processing emotions. This could help explain why patients with schizophrenia usually experience auditory hallucinations, the researchers say.
Meanwhile, the high-risk subjects who did not develop psychosis showed network connectivity nearly identical to that of the healthy subjects.
This type of distinctive brain activity could be useful as an early indicator of schizophrenia, especially since it is possible that it could be seen in even younger patients. The researchers are now performing similar studies with younger at-risk populations, including children with a family history of schizophrenia.
“That really gets at the heart of how we can translate this clinically, because we can get in earlier and earlier to identify aberrant networks in the hopes that we can do earlier interventions, and possibly even prevent psychiatric disorders," Whitfield-Gabrieli says.
She and her colleagues are now testing early interventions that could help to combat the symptoms of schizophrenia, including cognitive behavioral therapy and neural feedback. The neural feedback approach involves training patients to use mindfulness meditation to reduce activity in the superior temporal gyrus, which tends to increase before and during auditory hallucinations.
The researchers also plan to continue following the patients in the current study, and they are now analyzing some additional data on the white matter connections in the brains of these patients, to see if those connections might yield additional differences that could also serve as early indicators of disease.
The research was funded by the National Institutes of Health and the Ministry of Science and Technology of China. Collin was supported by a Marie Curie Global Fellowship grant from the European Commission.
Reprinted with permission of MIT News
Both schizophrenics and people with a common personality type share similar brain patterns.
- A new study shows that people with a common personality type share brain activity with patients diagnosed with schizophrenia.
- The study gives insight into how the brain activity associated with mental illnesses relates to brain activity in healthy individuals.
- This finding not only improves our understanding of how the brain works but may one day be applied to treatments.
Researchers have found that the signals in the brains of people with schizophrenia are similar to signals in the brains of people with schizotypal personalities. This discovery opens up new ways of looking at the condition as well as new avenues for treatment.
The study, published in Schizophrenia Bulletin, was carried out by scientists at the University of Nottingham, the Hospital for Sick Children in Toronto, and Cardiff University. Building off previous research and ideas on personality types going back decades, the study suggests that schizophrenia is not an entirely distinct condition but is instead an extreme variation of a common personality type.
The Schizotypal Personality
The schizotypal personality is characterized by social anxiety, magical thinking, unusual perceptual experiences, eccentric behavior, a lack of close friends, atypical speech patterns, and suspicions bordering on paranoia. These personality traits that, taken together, resemble the symptoms of schizophrenia.
A person with schizotypal personality disorder has these personality traits at a level where they begin to interfere with their lives, such as preventing them from forming close relationships, but they lack the hallucinations or delusions commonly associated with full-blown schizophrenia.1
The similarities between this personality type and the symptoms of schizophrenia interested the researchers. Since previous studies had shown that the electrophysiological response patterns in the brains of schizophrenic test subjects were often strange (the patterns showed a reduced post-movement beta rebound [PMBR] to be precise), the study looked at the brains of healthy patients to see if a person with a schizotypal personality would have similar brain activity.
Eduard Einstein (left) and his father Albert Einstein. Eduard was a brilliant student who wanted to study psychiatry before being diagnosed with schizophrenia at the age of 20. He lived a difficult life afterwards, dying in an institution at the age of 55.
(Einstein: His Life and Universe)
The experiment took 112 test subjects and had them answer a questionnaire, similar to others available online, to determine how many features of the schizotypal personality they had. They were then strapped into a magnetoencephalography (MEG) machine to have their brains scanned while they performed a simple motor task.
The volunteers were asked to move their index fingers when given a prompt. The reaction in their brains was recorded. The results were then compared to the answers the test subjects gave in their questionnaires.
As expected, the higher that a person scored on the schizotypal personality test, the more subdued their PMBR brain activity was—just as it is for patients with schizophrenia. This brain activity was particularly associated with scoring high on the parts of the test geared towards reveling the subject's tendencies to disorganized thinking and difficulty in forming interpersonal relationships.
What are the implications of this study?
Sample brain scans from the study. Here we see false color images of the brain, with areas that showed higher brain activity during the experiment shown in the most vibrant shades. The top row shows the change above baseline and the bottom shows the change below it. In a test subject with either schizophrenia or many schizotypal traits, the amplitude of the change would be greatly reduced.
(Hunt et al.)
The authors conclude the study by explaining
The finding that diminution of PMBR, previously reported in schizophrenia, is correlated with the severity of schizotypal features across the range observed in the general population, supports the hypothesis that at least some aspects of schizophrenia lie at the extreme end of a normal personality variant.
This idea, which has been around since the seventies, has recently been given more attention as a result of increasing interest in the concept of viewing mental disorders as existing on a gradient. This new view could lead to a better understanding of schizophrenia and perhaps even better treatments over the long run.
The results might also be of use in reducing the stigma around mental illness, as the study shows that the thought processes of people with schizophrenia are not categorically different from those of many other people. It is a difference of severity, not substance, which seems to separate those suffering from schizophrenia from the people who are merely eccentric.
Of course, more research is needed. At this moment, scientists aren't sure what neural mechanism even causes this brain activity, let alone how to treat the more extreme manifestations of the reduced activity seen in cases of schizophrenia.
Our understanding of mental illness has changed drastically over the last few decades as old ideas of what counted as mental illness are thrown out, and new ideas step up to replace old paradigms. The results of this study suggest that the brains of patients with this disease are more similar to the minds of healthy people than had previously been thought. While it will take years of more research before any medical advances are made on this information, our understanding of the people who go through life with this condition can be improved today.
1 Schizophrenia is not multiple personality disorder, despite the common misconception.