Paradoxical laughter is an exaggerated expression of humour which is unwarranted by external events. It may be uncontrollable laughter which may be recognised as inappropriate by the person involved. It is associated with mental illness, such as mania, hypomania or schizophrenia, schizotypal personality disorder and can have other causes. [1] [2] Paradoxical laughter is indicative of an unstable mood, often caused by the pseudobulbar affect, which can quickly change to anger and back again, on minor external cues.
This type of laughter can also occur at times when the fight-or-flight response may otherwise be evoked.
Paradoxical laughter has been consistently identified as a recurring emotional-cognitive symptom in schizophrenia diagnosis. Closely linked to paradoxical laughter is the symptom; inappropriate affect, defined by the APA Dictionary of Psychology as "emotional responses that are not in keeping with the situation or are incompatible with expressed thoughts or wishes". [3] An example of inappropriate affect with paradoxical laughter may be; expressions of joy when told about the death of a loved one. Inappropriate affect in schizophrenia includes, but is not limited to, paradoxical laughter, it also may involve unexpected bouts of aggression, sudden displays of sadness or undefinably bizarre behaviour.[ citation needed ]
Inappropriate affect officially falls in the category of a negative symptom in schizophrenia, measured on the SANS Scale when a diagnosis is made. [4] However, some dispute this and argue inappropriate affect does not suitably fall in the positive-negative symptom dichotomy. [5] Paradoxical laughter and other inappropriate emotional expressions were defining features of disorganised schizophrenia - one of five sub-types of schizophrenia previously defined in the DSM-IV. [5] The latest version DSM-V (2013), no longer recognises different types of schizophrenia. [6]
Research suggests that inappropriate affect, including paradoxical laughter, occurs due to a diminished ability for recognising facial expressions in schizophrenic patients. Patients with greater scoring on inappropriate affect, using the SANS measure, have been found to show a lower ability in recognising facial expressions measured through the Florida Affect Battery. [7] This suggests that deficits in facial expression recognition are what leads schizophrenic patients to behave in bizarre or inappropriate ways, such that, the inability to make sense of emotional cues results in mismatching or confused expressions. [8] This is linked to the idea of affective attunement, defined as, "the ability of one person to respond to another person's expressed feelings by matching the duration, intensity and rhythm of their emotional expressions". [8] Social interactions can break down when one person fails to sensitively respond to another's emotional signals. Because schizophrenics have an inhibited ability in recognising facial expressions they struggle to affectively relate to and communicate with others, in this sense, inappropriate affect can be recognised as a consequence of a restricted capacity for affective attunement. Deficits in affective perception have also been linked with autism spectrum disorder. [9] A number of studies have recognised inappropriate affect and other co-morbid symptoms present in both autism and schizophrenia, contributing to the idea that the two syndromes may in reality be opposite ends of a single spectrum. [10] [11] [12]
Corroborating evidence which measured schizophrenic patients' affective recognition, found a significant negative correlation with prevalence of inappropriate social and sexual behaviours and scoring on an affective recognition test. The study also found lower scores on the test were indicative of wider impoverished interpersonal relations and limited community participation, further suggesting deficits in affective attunement. After adjusting for intelligence and illness severity ratings, a strong correlation was still observed, suggesting inhibited affective recognition is linked and possibly causally related to the inappropriate affective and behavioural displays, including paradoxical laughter, in schizophrenic patients. [13]
Techniques involving precise facial muscle observations have also been used to measure inappropriate affect. When participants were asked to make specific facial expressions, researchers identified consistent differences between schizophrenics and controls. Between schizophrenic patients, a much more diverse and inconsistent display of emotions was observed compared to controls. As the trials were repeated, patients elicited expressions that became less and less emotive, suggesting the emergence of blunted affect. [14]
Several studies have examined inappropriate affect through imaging techniques observing regional brain abnormalities. Using fMRI techniques to measure activation across the brain, one experiment had patients reacting to and interacting with affective-facial stimuli. Two tasks were used: a discrimination task involving matching the correct emotion to a choice between two expressions, and a labelling task where patients had to verbally identify an emotion with a target facial expression. Compared to healthy controls, the schizophrenic patients showed significantly lower activation in the anterior cingulate on a discrimination task and lower activation in the amygdala-hippocampal area on a labelling task. The deficits in these regions present an explanation for the impoverished facial expression recognition in schizophrenics. When the target expression became more ambiguous, healthy controls showed a greater increase in activation in the right gyrus frontalis medialis, while schizophrenics showed consistently low levels of activation in this region. This evidence suggests that abnormalities in the anterior cingulate and amygdala may be responsible for displays of inappropriate affect. [15]
Other researchers also recognise the important role of the amygdala. Using a three-group experimental design, researchers compared levels of activation in the amygdalae of schizophrenics, their non-affected brothers and healthy controls. Using fMRI imaging, they found schizophrenic patients showed lowest activation in the amygdala when inducing a sad mood and lowest activation in the left thalamus for a task inducing happy mood, out of all three groups. The latter finding is theorised to be caused by amygdala dysfunction given the high levels of inter-connectivity between these regions which form part of the limbic system. Non-affected brothers also showed reduced regional activation during the task, compared to the healthy controls matched on key characteristics. This suggests that regional brain abnormalities linked to inappropriate affect, have a genetic foundation which, to a smaller degree, affect relatives of schizophrenics also. [16]
Most clinical research indicates a greater prevalence of blunted affect in schizophrenics as opposed to inappropriate affect. [14] However, studies throughout the 20th and 21st Century have documented and investigated its recurrence as a symptom linked to schizophrenia.
Observations of paradoxical laughter in schizophrenia date back to the 1940s. The subjective experience of patients was assessed to find inappropriate laughter most common at the early stage of schizophrenia. Through interviews it was found laughter was used by patients as a means to relieve built-up mental tension. Patients reported confusion in observing their environment causing cognitive strain and so used laughter as a way to release the tension and return to a blunted sense of feeling. [17]
More recent observations have found inappropriate affect to be specifically present during the early stages of the illness. Findings recorded paradoxical laughter most prevalent in the period of schizophrenia closely after onset, identifying a significant negative correlation between age of onset and chances of developing inappropriate affective symptoms. [18] [19] More specifically, very early onset patients had a much higher incidence of inappropriate affect (87.5%) compared to later onset patients (41.3%). The correlation was significant for both males and females though stronger for male patients. [18]
A mood swing is an extreme or sudden change of mood. Such changes can play a positive or a disruptive part in promoting problem solving and in producing flexible forward planning. When mood swings are severe, they may be categorized as part of a mental illness, such as bipolar disorder, where erratic and disruptive mood swings are a defining feature.
Facial perception is an individual's understanding and interpretation of the face. Here, perception implies the presence of consciousness and hence excludes automated facial recognition systems. Although facial recognition is found in other species, this article focuses on facial perception in humans.
In psychology, schizotypy is a theoretical concept that posits a continuum of personality characteristics and experiences, ranging from normal dissociative, imaginative states to extreme states of mind related to psychosis, especially schizophrenia. The continuum of personality proposed in schizotypy is in contrast to a categorical view of psychosis, wherein psychosis is considered a particular state of mind, which the person either has or does not have.
Disorganized schizophrenia, or hebephrenia, was a subtype of schizophrenia prior to 2013. Subtypes of schizophrenia were no longer recognized as separate conditions in the DSM 5, published in 2013. The disorder is no longer listed in the 11th revision of the International Classification of Diseases (ICD-11).
Affective neuroscience is the study of how the brain processes emotions. This field combines neuroscience with the psychological study of personality, emotion, and mood. The basis of emotions and what emotions are remains an issue of debate within the field of affective neuroscience.
Reduced affect display, sometimes referred to as emotional blunting or emotional numbing, is a condition of reduced emotional reactivity in an individual. It manifests as a failure to express feelings either verbally or nonverbally, especially when talking about issues that would normally be expected to engage emotions. In this condition, expressive gestures are rare and there is little animation in facial expression or vocal inflection. Additionally, reduced affect can be symptomatic of autism, schizophrenia, depression, post-traumatic stress disorder, depersonalization derealization disorder, schizoid personality disorder or brain damage. It may also be a side effect of certain medications.
Pseudobulbar affect (PBA), or emotional incontinence, is a type of neurological disorder characterized by uncontrollable episodes of crying or laughing. PBA occurs secondary to a neurologic disorder or brain injury. Patients may find themselves crying uncontrollably at something that is only slightly sad, being unable to stop themselves for several minutes. Episodes may also be mood-incongruent: a patient may laugh uncontrollably when angry or frustrated, for example. Sometimes, the episodes may switch between emotional states, resulting in the patient crying uncontrollably before dissolving into fits of laughter.
Multiple complex developmental disorder (MCDD) is a research category, proposed to involve several neurological and psychological symptoms where at least some symptoms are first noticed during early childhood and persist throughout life. It was originally suggested to be a subtype of pervasive developmental disorders (PDD) with co-morbid schizophrenia or another psychotic disorder; however, there is some controversy that not everyone with MCDD meets criteria for both PDD and psychosis. The term multiplex developmental disorder was coined by Donald J. Cohen in 1986.
Emotional responsivity is the ability to acknowledge an affective stimuli by exhibiting emotion. It is a sharp change of emotion according to a person's emotional state. Increased emotional responsivity refers to demonstrating more response to a stimulus. Reduced emotional responsivity refers to demonstrating less response to a stimulus. Any response exhibited after exposure to the stimulus, whether it is appropriate or not, would be considered as an emotional response. Although emotional responsivity applies to nonclinical populations, it is more typically associated with individuals with schizophrenia and autism.
Childhood schizophrenia is similar in characteristics of schizophrenia that develops at a later age, but has an onset before the age of 13 years, and is more difficult to diagnose. Schizophrenia is characterized by positive symptoms that can include hallucinations, delusions, and disorganized speech; negative symptoms, such as blunted affect and avolition and apathy, and a number of cognitive impairments. Differential diagnosis is problematic since several other neurodevelopmental disorders, including autism spectrum disorder, language disorder, and attention deficit hyperactivity disorder, also have signs and symptoms similar to childhood-onset schizophrenia.
Social-emotional agnosia, also known as emotional agnosia or expressive agnosia, is the inability to perceive facial expressions, body language, and voice intonation. A person with this disorder is unable to non-verbally perceive others' emotions in social situations, limiting normal social interactions. The condition causes a functional blindness to subtle non-verbal social-emotional cues in voice, gesture, and facial expression. People with this form of agnosia have difficulty in determining and identifying the motivational and emotional significance of external social events, and may appear emotionless or agnostic. Symptoms of this agnosia can vary depending on the area of the brain affected. Social-emotional agnosia often occurs in individuals with schizophrenia and autism. It is difficult to distinguish from, and has been found to co-occur with, alexithymia.
In psychiatry, stilted speech or pedantic speech is communication characterized by situationally inappropriate formality. This formality can be expressed both through abnormal prosody as well as speech content that is "inappropriately pompous, legalistic, philosophical, or quaint". Often, such speech can act as evidence for autism spectrum disorder (ASD) or a thought disorder, a common symptom in schizophrenia or schizoid personality disorder.
Emotional prosody or affective prosody is the various paralinguistic aspects of language use that convey emotion. It includes an individual's tone of voice in speech that is conveyed through changes in pitch, loudness, timbre, speech rate, and pauses. It can be isolated from semantic information, and interacts with verbal content.
The evolution of schizophrenia refers to the theory of natural selection working in favor of selecting traits that are characteristic of the disorder. Positive symptoms are features that are not present in healthy individuals but appear as a result of the disease process. These include visual and/or auditory hallucinations, delusions, paranoia, and major thought disorders. Negative symptoms refer to features that are normally present but are reduced or absent as a result of the disease process, including social withdrawal, apathy, anhedonia, alogia, and behavioral perseveration. Cognitive symptoms of schizophrenia involve disturbances in executive functions, working memory impairment, and inability to sustain attention.
Pain empathy is a specific variety of empathy that involves recognizing and understanding another person's pain.
Sex differences in schizophrenia are widely reported. Men and women exhibit different rates of incidence and prevalence, age at onset, symptom expression, course of illness, and response to treatment. Reviews of the literature suggest that understanding the implications of sex differences on schizophrenia may help inform individualized treatment and positively affect outcomes.
Emotion perception refers to the capacities and abilities of recognizing and identifying emotions in others, in addition to biological and physiological processes involved. Emotions are typically viewed as having three components: subjective experience, physical changes, and cognitive appraisal; emotion perception is the ability to make accurate decisions about another's subjective experience by interpreting their physical changes through sensory systems responsible for converting these observed changes into mental representations. The ability to perceive emotion is believed to be both innate and subject to environmental influence and is also a critical component in social interactions. How emotion is experienced and interpreted depends on how it is perceived. Likewise, how emotion is perceived is dependent on past experiences and interpretations. Emotion can be accurately perceived in humans. Emotions can be perceived visually, audibly, through smell and also through bodily sensations and this process is believed to be different from the perception of non-emotional material.
Emotions play a key role in overall mental health, and sleep plays a crucial role in maintaining the optimal homeostasis of emotional functioning. Deficient sleep, both in the form of sleep deprivation and restriction, adversely impacts emotion generation, emotion regulation, and emotional expression.
Schizophrenia is a mental disorder characterized by persistent hallucinations, delusions, paranoia, and thought disorder. These experiences are evident in multiple sensory modalities and include deviation in all facets of thought, cognition, and emotion. Compared to other psychological disorders like major depressive disorder (MDD) and generalized anxiety disorder (GAD), schizophrenia has significantly higher heritability. Schizophrenia has been found to present cross-culturally, and it almost always has 0.1% prevalence in a given population, although some studies have cast doubts on this. It has been hypothesized that schizophrenia is unique to human beings and has existed for a long time.
Functional MRI imaging methods have allowed researchers to combine neurocognitive testing with structural neuroanatomical measures, consider cognitive and affective paradigms, and create computer-aided diagnosis techniques and algorithms. Functional MRI has several benefits, such as its non-invasive quality, relatively high spatial resolution, and decent temporal resolution. Recent studies have used fMRI to explore specific brain networks, such as the salience network and default mode network, to understand their roles in schizophrenia-related symptoms. Alterations in these networks may affect self-referential thoughts and responses to external stimuli, potentially contributing to symptoms like hallucinations and disorganized thinking. One particular method used in recent research is resting-state functional magnetic resonance imaging, rs-fMRI. fMRI imaging has been applied to numerous behavioral studies for schizophrenia, the findings of which have hinted toward potential brain regions that govern key characteristics in cognition and affect.
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