Social Cues Are Difficult for People with Schizophrenia

Social Cues Are Difficult for People with Schizophrenia New research finds that impairment in a brain area make it difficult for people with schizophrenia to understand the nonverbal actions of others. “Misunderstanding social situations and interactions are core deficits in schizophrenia,” said psychologist Dr. Sohee Park of Vanderbilt University. “Our findings may help explain the origins of some of the delusions involving perception and thoughts experienced by those with schizophrenia.” Researchers found that a particular brain area, the posterior superior temporal sulcus or STS, appears to be implicated in this deficit. “Using brain imaging together with perceptual testing, we found that a brain area in a neural network involved in perception of social stimuli responds abnormally in individuals with schizophrenia,” said co-author Randolph Blake, Ph.D. “We found this brain area fails to distinguish genuine biological motion from highly distorted versions of that motion.” “We have found… that people with schizophrenia tend to ‘see’ living things in randomness and this subjective experience is correlated with an increased activity in the (posterior) STS,” the authors wrote. “In the case of biological motion perception, these self-generated, false impressions of meaning can have negative social consequences, in that schizophrenia patients may misconstrue the actions or intentions of other people.” In their experiments, the researchers compared the performance of people with schizophrenia to that of healthy controls on two visual tasks. One task involved deciding whether or not an animated series of lights depicted the movements of an actor’s body. The second task entailed judging subtle differences in the actions depicted by two similar animations viewed side by side. On both tasks, people with schizophrenia performed less well than the healthy controls. Next, the researchers measured brain activity using functional magnetic resonance imaging (fMRI) while the subjects—healthy controls and schizophrenia patients—performed a version of the side-by-side task. Once again, the individuals with schizophrenia performed worse on the task. The researchers were then able to correlate those performance deficits with the brain activity in each person. Researchers do not yet understand this specific brain area in schizophrenia patients fails to differentiate normal human activity from non-human motion. They speculate that this abnormal brain activation contributes to the patients’ difficulties reading social cues in the actions of others. Their findings are published in the journal PLoS ONE. Source: Vanderbilt University

Postural Problems a Sign of Bipolar Illness?

Postural Problems a Sign of Bipolar Illness?Although motor deficits often accompany a mood or psychiatric disorder, most researchers have not targeted motor areas as a method to improve mental health. In a new study, researchers at Indiana University suggests that postural control problems may be a core feature of bipolar disorder, not just a random symptom. The investigators believe attention to the postural problems can provide insights both into areas of the brain affected by the psychiatric disorder and new potential targets for treatment. Bipolar disorder is a severe psychiatric disorder characterized by extreme, debilitating mood swings and unusual shifts in a person’s energy and ability to function. Balance, postural control and other motor control issues are frequently experienced by people with mood and psychiatric disorders such as bipolar disorder and schizophrenia, and neurological disorders such as Huntington’s and Parkinson’s disease. In this study, published in the journal PLoS ONE, researchers surmised that problems with postural control — maintaining balance while holding oneself upright — are a core component of bipolar disorder. As such, the researchers believe it is possible that the motor abnormalities could appear before other symptoms, signaling an increased risk for the disorder. According, researchers wanted to know if therapies that improve motor symptoms may also help mood disorders. “For a number of psychological disorders, many different psychiatric treatments and therapies have been tried, with marginal effects over the long term. Researchers are really starting to look at new targets,” said Amanda Bolbecker, Ph.D., lead author of the study. “Our study suggests that brain areas traditionally believed to be responsible for motor behavior might represent therapeutic targets for bipolar disorder.” The link between motor and mental is not as distant as some would believe. For example, try as we might, humans cannot stand perfectly still. “Instead, we make small adjustments at our hips and ankles based on what our eyes, muscles, ligaments, tendons, and semi-circular canals tells us,” said S. Lee Hong, Ph.D., a study co-author. “The better these sensory sources are integrated, the less someone sways.” Areas of the brain that are critical for motor control, mainly the cerebellum, basal ganglia and brain stem, also aid in mood regulation and are areas where abnormalities often are found in people with bipolar disorder. Postural sway — a measure of the endless adjustments people make in an attempt to stand still — is considered a sensitive gauge of motor control that likely is affected by these abnormalities. In the study, participants who had bipolar disorder displayed more postural sway, particularly when their eyes were closed, than study participants who had no psychological disorders. The troubles, which involved the study participants’ proprioception, or ability to process non-visual sensory information related to balance, were not affected by their mood or the severity of their disorder. “It appears that people with bipolar disorder process sensory information differently and this is seen in their inability to adapt their movement patterns to different conditions, such as eyes open vs. eyes closed or feet together vs. feet apart,” said Hong, whose research focuses on how humans control motion. “The different conditions will cause people to use the information their senses provide differently, in order to allow them to maintain their balance.” Additional research is called for as investigations involving motor control, mood and psychiatric disorders are complicated by the fact that the primary treatment for these disorders is medication, which can have severe side effects including motor control problems. Source: Indiana University

Dopamine Release Fuels Anxiety in Brains of Anorexics

Dopamine Release Fuels Anxiety in Brains of AnorexicsAlthough most people find pleasure in eating and even have a difficult time refraining from foods they love, individuals suffering from anorexia nervosa often say that eating makes them feel more anxious. Instead, refusing to eat — something called food refusal – is what brings more pleasure. New research, published online in the journal International Journal of Eating Disorders, helps explain why these symptoms occur in anorexia. For the study, scientists administered a one-time dose of the drug amphetamine which releases dopamine in the brain; positron emission tomography (PET) was then used to visualize the subsequent dopamine activity. In healthy subjects without an eating disorder, the amphetamine-induced release of dopamine was associated with feelings of extreme pleasure in the brain’s “reward center.” However, in people with anorexia, amphetamine made them feel anxious and activated the part of the brain that worries about consequences. “This is the first study to demonstrate a biological reason why individuals with anorexia nervosa have a paradoxical response to food,” said Walter Kaye, M.D., professor of psychiatry and director of the Eating Disorder Treatment and Research Program at the University of California-San Diego School of Medicine. “It’s possible that when people with anorexia nervosa eat, the related release of the neurotransmitter dopamine makes them anxious, rather than experiencing a normal feeling of reward. It is understandable why it is so difficult to get people with anorexia to eat and gain weight, because food generates intensely uncomfortable feelings of anxiety.” Significantly, the study included individuals who had recovered from anorexia for at least a year, suggesting that the feeling provoked was possibly due to pre-existing traits, rather than a response to being extremely underweight. Currently, there are few treatments proven to reduce core symptoms in anorexia, including eating-induced anxiety. Finding ways to help anorexic individuals eat and gain weight is necessary for treatment, even when food is still accompanied by severe anxiety. The study was supported in part by the National Institute of Mental Health and the Prince Foundation. Source:  University of California

Crossing Arms Confuses Brain, Relieves Hand Pain

Crossing Arms Confuses Brain But Relieves Hand PainIf your hand hurts, simply cross your arms; it will confuse the brain and reduce your pain intensity, according to scientists at University College London. Researchers believe this happens because of conflicting information between two of the brain’s maps: the one for your body and the one for external space. Since the left hand typically performs actions on the left side of space (and the right hand performs on the right side), these two maps work together to create powerful impulses in response to stimuli. When the arms are crossed, however, the two maps are mismatched and information processing becomes weaker — resulting in less pain. “Perhaps when we get hurt, we should not only ‘rub it better’ but also cross our arms,” said lead author Giandomenico Iannetti of the UCL department of Physiology, Pharmacology and Neuroscience. Using a laser, scientists produced a four millisecond pin prick of “pure pain” (pain without touch) on the hands of a small group of eight volunteers.  It was then repeated with their arms crossed. The partipants’ brain responses to the pain were measured through electroencephalography (EEG); the volunteers also gave a rating on how much pain they felt during each circumstance. The results from both the EEG and the participants’ reports revealed that the perception of pain was weaker when the arms were crossed. “In everyday life you mostly use your left hand to touch things on the left side of the world, and your right hand for the right side of the world — for example when picking up a glass of water on your right side you generally use your right hand,” said Iannetti. “This means that the areas of the brain that contain the map of the right body and the map of right external space are usually activated together, leading to highly effective processing of sensory stimuli. When you cross your arms these maps are not activated together anymore, leading to less effective brain processing of sensory stimuli, including pain, being perceived as weaker.” According to the scientists, this new research could lead to novel clinical therapies to reduce pain that exploit the brain’s way of representing the body. The study is published in the journal PAIN. Source: University College London
Skip to toolbar