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One contribution to the characteristic social impairment in schizophrenia might be an impaired ability to imitate the actions of others, a recent study suggests.
Using functional magnetic resonance imaging (fMRI) comparisons between healthy and schizophrenia participants’ brains, Katharine N. Thakkar, Ph.D., and her associates at Vanderbilt University in Nashville, Tenn., identified reduced activity among the schizophrenia patients in the parts of the brain involved with the "mirror neuron" network, which is partly responsible for imitation activities.
"Our results indicate abnormal neural activity during action imitation and observation in patients with schizophrenia," Dr. Thakkar and her coauthors reported (Am. J. Psychiatry 2014;171:539-548).
In earlier primate studies, researchers previously identified a network of mirror neurons in the human brain that receive information from the posterior superior temporal sulcus and operate in the temporoparietal and frontal regions. The researchers therefore compared the fMRI brain images of 16 medicated schizophrenia patients to the brain images of 16 healthy comparison controls, matched in age, sex, IQ, and handedness.
During the experiment, the subjects were expected to press one of three buttons based on each of three different visual cues: a video with a hand pressing a button (imitation), a still image with a pointing hand (nonimitative action), and a diagram (nonimitative action). The subjects also observed these visual cues without pressing the buttons to provide brain activity data during biological motion perception.
The results showed reduced activity in the posterior superior temporal sulcus during both imitation and action observation in the schizophrenia patients, compared with the healthy controls. Meanwhile, during nonimitative action, the schizophrenia patients showed greater activity than the healthy controls in the posterior superior temporal sulcus and in the inferior parietal lobe. Patients with a lower score on the Brief Psychiatric Rating Scale showed greater activity in the right posterior superior temporal sulcus during action imitation, and those with a lower Scale for the Assessment of Negative Symptoms score showed greater activity in the right inferior parietal lobe during nonimitative action.
Dr. Thakkar and her associates cited several limitations of their study. For example, the patients with schizophrenia were medicated, and the effects of antipsychotic medication on imitation are unknown. However, the investigators did find that "brain activation in patients with higher medication dosages looked more like that of healthy subjects."
Together, the findings point to cognitive deficits in the ability to observe and imitate others in those with schizophrenia. Action imitation is regarded as a "building block of social cognition," at the root of "the ability to interpret the minds of others," the authors wrote.
The study was supported by the National Institute of Mental Health, a Netherlands Organization for Scientific Research Rubicon grant, and the National Center for Research Resources. The authors reported no disclosures.
"These findings are similar to reports over the past two decades in studies of neurocognitive functioning using much more complex procedures. There too, the findings suggested underactivation of important regions defined by the brain functioning of healthy individuals during task performance and overactivation of regions that appear less relevant to the task immediately at hand.
"As people with schizophrenia commonly have major social problems, understanding their origin, both neurobiological and behavioral, is critically important. Many higher-level social skills are learned through observation and imitation. From the beginning, infants learn many skills through imitation, starting with basic motor skills learned in the preverbal period.
"This paper presents critical data suggesting that the basic neurobiological processes of observation and imitation of others may be deficient in people with schizophrenia, with many higher levels impacted in a bottom-to-top manner. As a result, these findings have the potential to have identified the first step in the cascade of poor social functioning in schizophrenia: the inability to learn through basic observational and imitative processes."
Philip D. Harvey, Ph.D., is professor of psychiatry and behavioral sciences at the University of Miami. These comments were adapted from his editorial in the May issue of the American Journal of Psychiatry.
"These findings are similar to reports over the past two decades in studies of neurocognitive functioning using much more complex procedures. There too, the findings suggested underactivation of important regions defined by the brain functioning of healthy individuals during task performance and overactivation of regions that appear less relevant to the task immediately at hand.
"As people with schizophrenia commonly have major social problems, understanding their origin, both neurobiological and behavioral, is critically important. Many higher-level social skills are learned through observation and imitation. From the beginning, infants learn many skills through imitation, starting with basic motor skills learned in the preverbal period.
"This paper presents critical data suggesting that the basic neurobiological processes of observation and imitation of others may be deficient in people with schizophrenia, with many higher levels impacted in a bottom-to-top manner. As a result, these findings have the potential to have identified the first step in the cascade of poor social functioning in schizophrenia: the inability to learn through basic observational and imitative processes."
Philip D. Harvey, Ph.D., is professor of psychiatry and behavioral sciences at the University of Miami. These comments were adapted from his editorial in the May issue of the American Journal of Psychiatry.
"These findings are similar to reports over the past two decades in studies of neurocognitive functioning using much more complex procedures. There too, the findings suggested underactivation of important regions defined by the brain functioning of healthy individuals during task performance and overactivation of regions that appear less relevant to the task immediately at hand.
"As people with schizophrenia commonly have major social problems, understanding their origin, both neurobiological and behavioral, is critically important. Many higher-level social skills are learned through observation and imitation. From the beginning, infants learn many skills through imitation, starting with basic motor skills learned in the preverbal period.
"This paper presents critical data suggesting that the basic neurobiological processes of observation and imitation of others may be deficient in people with schizophrenia, with many higher levels impacted in a bottom-to-top manner. As a result, these findings have the potential to have identified the first step in the cascade of poor social functioning in schizophrenia: the inability to learn through basic observational and imitative processes."
Philip D. Harvey, Ph.D., is professor of psychiatry and behavioral sciences at the University of Miami. These comments were adapted from his editorial in the May issue of the American Journal of Psychiatry.
One contribution to the characteristic social impairment in schizophrenia might be an impaired ability to imitate the actions of others, a recent study suggests.
Using functional magnetic resonance imaging (fMRI) comparisons between healthy and schizophrenia participants’ brains, Katharine N. Thakkar, Ph.D., and her associates at Vanderbilt University in Nashville, Tenn., identified reduced activity among the schizophrenia patients in the parts of the brain involved with the "mirror neuron" network, which is partly responsible for imitation activities.
"Our results indicate abnormal neural activity during action imitation and observation in patients with schizophrenia," Dr. Thakkar and her coauthors reported (Am. J. Psychiatry 2014;171:539-548).
In earlier primate studies, researchers previously identified a network of mirror neurons in the human brain that receive information from the posterior superior temporal sulcus and operate in the temporoparietal and frontal regions. The researchers therefore compared the fMRI brain images of 16 medicated schizophrenia patients to the brain images of 16 healthy comparison controls, matched in age, sex, IQ, and handedness.
During the experiment, the subjects were expected to press one of three buttons based on each of three different visual cues: a video with a hand pressing a button (imitation), a still image with a pointing hand (nonimitative action), and a diagram (nonimitative action). The subjects also observed these visual cues without pressing the buttons to provide brain activity data during biological motion perception.
The results showed reduced activity in the posterior superior temporal sulcus during both imitation and action observation in the schizophrenia patients, compared with the healthy controls. Meanwhile, during nonimitative action, the schizophrenia patients showed greater activity than the healthy controls in the posterior superior temporal sulcus and in the inferior parietal lobe. Patients with a lower score on the Brief Psychiatric Rating Scale showed greater activity in the right posterior superior temporal sulcus during action imitation, and those with a lower Scale for the Assessment of Negative Symptoms score showed greater activity in the right inferior parietal lobe during nonimitative action.
Dr. Thakkar and her associates cited several limitations of their study. For example, the patients with schizophrenia were medicated, and the effects of antipsychotic medication on imitation are unknown. However, the investigators did find that "brain activation in patients with higher medication dosages looked more like that of healthy subjects."
Together, the findings point to cognitive deficits in the ability to observe and imitate others in those with schizophrenia. Action imitation is regarded as a "building block of social cognition," at the root of "the ability to interpret the minds of others," the authors wrote.
The study was supported by the National Institute of Mental Health, a Netherlands Organization for Scientific Research Rubicon grant, and the National Center for Research Resources. The authors reported no disclosures.
One contribution to the characteristic social impairment in schizophrenia might be an impaired ability to imitate the actions of others, a recent study suggests.
Using functional magnetic resonance imaging (fMRI) comparisons between healthy and schizophrenia participants’ brains, Katharine N. Thakkar, Ph.D., and her associates at Vanderbilt University in Nashville, Tenn., identified reduced activity among the schizophrenia patients in the parts of the brain involved with the "mirror neuron" network, which is partly responsible for imitation activities.
"Our results indicate abnormal neural activity during action imitation and observation in patients with schizophrenia," Dr. Thakkar and her coauthors reported (Am. J. Psychiatry 2014;171:539-548).
In earlier primate studies, researchers previously identified a network of mirror neurons in the human brain that receive information from the posterior superior temporal sulcus and operate in the temporoparietal and frontal regions. The researchers therefore compared the fMRI brain images of 16 medicated schizophrenia patients to the brain images of 16 healthy comparison controls, matched in age, sex, IQ, and handedness.
During the experiment, the subjects were expected to press one of three buttons based on each of three different visual cues: a video with a hand pressing a button (imitation), a still image with a pointing hand (nonimitative action), and a diagram (nonimitative action). The subjects also observed these visual cues without pressing the buttons to provide brain activity data during biological motion perception.
The results showed reduced activity in the posterior superior temporal sulcus during both imitation and action observation in the schizophrenia patients, compared with the healthy controls. Meanwhile, during nonimitative action, the schizophrenia patients showed greater activity than the healthy controls in the posterior superior temporal sulcus and in the inferior parietal lobe. Patients with a lower score on the Brief Psychiatric Rating Scale showed greater activity in the right posterior superior temporal sulcus during action imitation, and those with a lower Scale for the Assessment of Negative Symptoms score showed greater activity in the right inferior parietal lobe during nonimitative action.
Dr. Thakkar and her associates cited several limitations of their study. For example, the patients with schizophrenia were medicated, and the effects of antipsychotic medication on imitation are unknown. However, the investigators did find that "brain activation in patients with higher medication dosages looked more like that of healthy subjects."
Together, the findings point to cognitive deficits in the ability to observe and imitate others in those with schizophrenia. Action imitation is regarded as a "building block of social cognition," at the root of "the ability to interpret the minds of others," the authors wrote.
The study was supported by the National Institute of Mental Health, a Netherlands Organization for Scientific Research Rubicon grant, and the National Center for Research Resources. The authors reported no disclosures.
FROM THE AMERICAN JOURNAL OF PSYCHIATRY
Key clinical point: The nature of social dysfunction within schizophrenia can be understood by looking at activity within two regions of the brain: the posterior superior temporal sulcus and the inferior parietal lobe.
Major finding: Compared with healthy controls, schizophrenia patients showed poorer activation of the mirror neuron network, responsible for the ability to imitate others; the activation correlated with symptom severity and social functioning.
Data source: The findings are based on an analysis of functional magnetic resonance imaging in 16 healthy subjects and in 16 medicated schizophrenia subjects from a Nashville, Tenn., psychiatric facility.
Disclosures: The study was supported by the National Institute of Mental Health, a Netherlands Organization for Scientific Research Rubicon grant, and the National Center for Research Resources. The authors reported no disclosures.