More than an imitation game: Top-down modulation of the human mirror system

All interpersonal interactions are underpinned by action: perceiving and understanding the actions of others, and responding by planning and performing self-made actions. Perception of action, both self-made and observed, informs ongoing motor responses by iterative feedback within a perception-action loop. This fundamental phenomenon occurs within single-cells of the macaque brain which demonstrate sensory and motor response properties. These ‘mirror’ neurons have led to a swathe of research leading to the broadly accepted idea of a human mirror system. The current review examines the putative human mirror system literature to highlight several inconsistencies in comparison to the seminal macaque data, and ongoing controversies within human focused research (including mirror neuron origin and function). In particular, we will address the often-neglected other side to the ‘mirror’: complementary and opposing actions. We propose that engagement of the mirror system in meeting changing task-demands is dynamically modulated via frontal control networks.     

Testing the connection of the mirror system and speech: how articulation affects imitation in a simple response task

There seems to be a close connection between speech and action, which we experience almost daily when we try to support our verbal expressions with gestures. Recently, the assumption that the language system and the action system are intimately linked has received support from brain imaging research showing that imitation and language production involve the same cortical structure, namely Broca's area. However, if the assumption of a functional interdependency holds true, one would predict that language production and imitation should interact on the behavioural level. We have tested this assumption in a series of experiments in which we investigated the influence of an articulation task on imitation. Here we show that articulation has a specific influence on the imitation of finger movements when compared to a non-imitative stimulus-response (S-R) association. These findings provide strong experimental support for the assumption that language production and imitation share common functional mechanisms.     

The human mirror system: a motor resonance theory of mind-reading

Electrophysiological data confirm the existence of neurons that respond to both motor and sensory events in the macaque brain. These mirror neurons respond to execution and observation of goal-orientated actions. It has been suggested that they comprise a neural basis for encoding an internal representation of action. In this paper the evidence for a parallel system in humans is reviewed and the implications for human theory of mind processing are discussed. Different components of theory of mind are discussed; the evidence for mirror activity within subtypes is addressed. While there is substantial evidence for a human mirror system, there are weaknesses in the attempts to localize such a system in the brain. Preliminary evidence indicates that mirror neurons may be involved in theory of mind; however, these data by their very nature are reliant on the presence, and precise characterization, of the human mirror system.     

Reflecting on the mirror neuron system in autism: A systematic review of current theories

There is much interest in the claim that dysfunction of the mirror neuron system in individuals with autism spectrum condition causes difficulties in social interaction and communication. This paper systematically reviews all published studies using neuroscience methods (EEG/MEG/TMS/eyetracking/EMG/fMRI) to examine the integrity of the mirror system in autism. 25 suitable papers are reviewed. The review shows that current data are very mixed and that studies using weakly localised measures of the integrity of the mirror system are hard to interpret. The only well localised measure of mirror system function is fMRI. In fMRI studies, those using emotional stimuli have reported group differences, but studies using non-emotional hand action stimuli do not. Overall, there is little evidence for a global dysfunction of the mirror system in autism. Current data can be better understood under an alternative model in which social top-down response modulation is abnormal in autism. The implications of this model and future research directions are discussed.     

Morphological differences in the mirror neuron system in Williams syndrome

Williams syndrome (WS) is a genetic condition characterized by an overly gregarious personality, including high empathetic concern for others. Although seemingly disparate from the profile of autism spectrum disorder (ASD), both are associated with deficits in social communication/cognition. Notably, the mirror neuron system (MNS) has been implicated in social dysfunction for ASD; yet, the integrity of this network and its association with social functioning in WS remains unknown. Magnetic resonance imaging (MRI) methods were used to examine the structural integrity of the MNS of adults with WS versus typically developing (TD) individuals. The Social Responsiveness Scale (SRS), a tool typically used to screen for social features of ASD, was also employed to assess the relationships between social functioning with the MNS morphology in WS participants. WS individuals showed reduced cortical surface area of MNS substrates yet relatively preserved cortical thickness as compared to TD adults. Increased cortical thickness of the inferior parietal lobule (IPL) was associated with increased deficits in social communication, social awareness, social cognition, and autistic mannerisms. However, social motivation was not related to anatomical features of the MNS. Our findings indicate that social deficits typical to both ASD and WS may be attributed to an aberrant MNS, whereas the unusual social drive marked in WS is subserved by substrates distinct from this network.     

Schizophrenia, cancer and obstetric complications in an evolutionary perspective-an empirically based hypothesis

Objective

Patients diagnosed with schizophrenia have reduced fecundity and premature mortality (both accidental and violent) with no obvious compensatory advantages among kin. The prevalence of the disorder is around 0.7/1%, higher than the expected prevalence of spontaneous mutations. Genes favoring schizophrenia may have been positively selected in the environment of evolutionary adaptation. Literature on potential adaptive genes is reviewed within an evolutionary framework.

Methods

Literature search on major scientific search engine (PubMed/Medline, Ovid/PsychInfo) on papers aimed at investigating potential pathways justifying a mutation-selection balanced model. Findings are presented with a narrative touch to favor readability and understanding.

Results

Reduced incidence of cancer in both patients diagnosed with schizophrenia and their siblings was reported worldwide. Such findings are notable given higher cancer risk factors in schizophrenia, i.e., smoking, alcohol abuse, obesity, poor diet, and poor adherence to therapy. Some genes involved in cancer proliferation might as well confer protective advantage in immune-surveillance, inflammation, vascular proliferation or apoptosis that otherwise will adversely affect early neurodevelopment.

Conclusion

Evidence that reduced risk of certain somatic diseases is associated with schizophrenia is quite significant to progress in the evolutionary epidemiological analysis of psychopathology.     

Cortical neural activity evoked by bilateral and unilateral mirror therapy after stroke

ObjectiveThis study aimed to investigate the differential effects of bilateral and unilateral mirror therapy (MT) on motor cortical activations in stroke patients by magnetoencephalography (MEG).MethodsSixteen stroke patients and 16 right-handed healthy volunteers were recruited. All participants were required to perform 4 conditions: resting, no mirror with bilateral hand movements (Bilateral-No mirror), mirror with bilateral hand movements (Bilateral-Mirror) and mirror with unilateral hand movements (Unilateral-Mirror). Beta oscillatory activities in the primary motor cortex (M1) were collected during each condition using MEG. The percentage change of beta oscillatory activity was calculated for each condition to correct the baseline differences.ResultsIn the stroke group, the percentage change of M1 beta oscillatory activity significantly decreased more in the Bilateral-Mirror condition than in the Bilateral-No mirror and Unilateral-Mirror conditions. In the healthy group, no significant differences in the percentage change of beta oscillatory activity were found among the 3 conditions. Further, a significant difference in the percentage change of beta oscillatory activity only in the Bilateral-Mirror condition was found between the 2 groups.ConclusionsThis study provides new information on the differential cortical activations modulated by bilateral and unilateral MT.SignificanceBilateral MT led to greater M1 neural activities than unilateral MT and bilateral movements without a mirror in stroke patients.     

镜像书写与大脑功能关系的探讨

本文检测了学龄前儿童72名,学龄儿童40名和弱智学龄儿童60名的镜像书写情况。检查结果表明学龄前儿童组、学龄儿童组和弱智学龄儿童组用左手书写时镜像书写的出现率分别为45.8％、10％和43.3％;定向力差者分别为47.2％、22.5％和41.7％。弱智学龄儿童中镜像书写出现率较高是因智力落后使书写运动一图式和镜像书写运动一图式在两侧大脑半球建立得不够牢固有关。所以是否可考虑镜像书写归为儿童智力测定的项目之     

Schizophrenia and neurogenesis: A stem cell approach

Several recent research findings indicate that schizophrenia (SCZ) may begin with an abnormal neuro-genesis from embryonic Neural Stem Cells (NSCs) and that this process may be particularly vulnerable to a number of genetic and/or environmental disturbances of early brain development. Since it is now well known that neurogenesis is not confined to the womb, but is a protracted process continuing in postnatal life well into adolescence and beyond, and since in the majority of subjects diagnosed with SCZ the first psychotic break occurs in late adolescence or early adulthood, the aim of our paper is to summarize the main findings supporting a possible link between changes in developmental postnatal neurogenesis and SCZ, with a specific focus on the critical period of adolescence and associated environmental risk factors. Establishing a significant role of adult neurogenesis in the emergence of psychosis will help us not only to better understand the pathogenesis of this neuopsychiatric disorder, but also to provide the key to potential strategies toward possible treatments and/or early corrective interventions.     

Learning-related changes of brain activation in the visual ventral stream: an fMRI study of mirror reading skill

A previous neuroimaging study has indicated that the visual dorsal stream may contribute to accurate reading of mirror-reversed words. However, the role of the visual ventral stream in the learning of mirror reading skill remains ambiguous. In the present fMRI study, we investigated learning-related changes in brain activation in the visual ventral stream in a mirror reading task. Subjects participated in three successive runs of the mirror reading task, in each of which they were asked to read mirror-reversed words and normal words as accurately and as quickly as possible. The behavioral data for the mirror reading condition showed significant improvement in reaction time but not in performance accuracy across the three runs. The activation data showed different learning-associated patterns related to the right and left visual ventral streams. On the right side, activity related to the reading of mirror stimuli was significantly greater than that related to normal stimuli in the first run only, whereas on the left side it was greater in all runs. Additional correlation analysis between response time data and percentage signal changes only in the mirror reading condition showed significant correlation on the right visual ventral stream in the first run only, whereas that on the left visual ventral stream was found only in the third run. The dissociable response between the right and left visual ventral streams may reflect learning-related changes in reading strategy and may be critical in improving the speed of reading mirror-reversed words.     

Heritability of Schizophrenia and Schizophrenia Spectrum Based on the Nationwide Danish Twin Register

Background

Twin studies have provided evidence that both genetic and environmental factors contribute to schizophrenia (SZ) risk. Heritability estimates of SZ in twin samples have varied methodologically. This study provides updated heritability estimates based on nationwide twin data and an improved statistical methodology.

1例汶川地震所致老年精神分裂症报道

1 临床资料 患者,男性,71岁,四川省汶川县增坡村人,2008年6月4日我院医疗分队前去当地巡诊时家人带来就诊.2008年5月12日汶川地震发生后患者出现双颞部波动性疼痛,每日间断睡眠半小时左右,易醒、多梦,一些话语旁人无法理解,对亲人冷漠,对周围事物无动于衷,活动减少.     

吸烟行为和精神分裂症

吸烟行为与肿瘤、心血管疾病等慢性疾病的关系已获得了多数学者的认同,而精神分裂症患者的吸烟行为比普通人群更为常见,但吸烟对其影响却一直备受争议。鉴于此,本文将分别从阴性症状、阳性症状、认知症状、药物不良反应、血药浓度等多个方面阐述吸烟行为对精神分裂症患者的影响。     

Reward modulates the mirror neuron system in schizophrenia: A study into the mu rhythm suppression,empathy, and mental state attribution

Impairments in the mirror neuron system (MNS) have been implicated as a possible underlying neurological basis for deficits in higher-level social cognition in schizophrenia. Previous work testing this hypothesis has used the electroencephalographic mu rhythm as an index of MNS activity, with studies showing mixed results. Here we investigated the role that reward plays in modulating the mu rhythm, and its association with empathy and emotional mental state reasoning. A group of schizophrenia patients and a healthy control group completed an action observation paradigm in which they watched actions that were financially rewarding, punishing, or neutral. Patients showed intact reward-related modulation of the mu rhythm, and greater mu suppression was associated with greater negative symptoms. There was also a trend for reduced mu suppression in patients. Furthermore, both empathy and emotional mental state reasoning were associated with the degree of mu suppression, but only in healthy controls. These findings confirm the association between the mu suppression and high-level social cognition. It is possible that schizophrenia patients utilize different cognitive routes to infer mental states. The demonstration that reward influences the degree of mu suppression in schizophrenia patients may help to account for previous conflicting findings in the literature.     

Career Development in Schizophrenia: A Heuristic Framework

Adults with schizophrenia continue to have poor rates of competitive employment. We have learned how to support individuals in the workplace with supported employment (SE); but have paid limited attention to early vocational identity development, work antecedents, illness characteristics, and career preferences. Vocational identity development is an important and natural condition of human growth for all persons and is well-researched in career counseling. For young adults with schizophrenia, the predictor of positive work outcome with the most evidence has been that working competitively prior to illness leads to better chances for work post-diagnosis. A heuristic framework is proposed to conceptualize how pre-illness vocational development (paid and unpaid) plus life cycle supports can provide direction to the individual in their work recovery.     

Effective connectivity of the human mirror neuron system during social cognition

The human mirror neuron system (MNS) can be considered the neural basis of social cognition. Identifying the global network structure of this system can provide significant progress in the field. In this study, we use dynamic causal modeling (DCM) to determine the effective connectivity between central regions of the MNS for the first time during different social cognition tasks. Sixty-seven healthy participants completed fMRI scanning while performing social cognition tasks, including imitation, empathy and theory of mind. Superior temporal sulcus (STS), inferior parietal lobule (IPL) and Brodmann area 44 (BA44) formed the regions of interest for DCM. Varying connectivity patterns, 540 models were built and fitted for each participant. By applying group-level analysis, Bayesian model selection and Bayesian model averaging, the optimal family and model for all experimental tasks were found. For all social-cognitive processes, effective connectivity from STS to IPL and from STS to BA44 was found. For imitation, additional mutual connections occurred between STS and BA44, as well as BA44 and IPL. The results suggest inverse models in which the motor regions BA44 and IPL receive sensory information from the STS. In contrast, for imitation, a sensory loop with an exchange of motor-to-sensory and sensory-to-motor information seems to exist.     

Bridging Psychiatric Rehabilitation and Recovery in Schizophrenia: A Life's Work

For many years, schizophrenia was thought of as a lifelong deteriorating illness with little hope of improvement. However, recent naturalistic studies demonstrate that the course of the disorder is more positive than had been previously thought. With the advent of more effective pharmacological and psychosocial interventions for those with the disorder who continue to experience impairment and disabilities, the potential of recovery in schizophrenia has become increasingly acknowledged. This paper presents a brief history of the development of psychosocial interventions for schizophrenia and the role Robert Paul Liberman played in advancing psychiatric rehabilitation as an effective strategy for helping individuals with serious psychiatric illnesses live richer lives in the community. The core tenets of Liberman's work—community-based care, designing interventions to bolster (re)hablitation of life skills critical to successful functional adjustment, promoting widespread availability of effective interventions, emphasizing personalized goals as legitimate treatment targets, and recognizing the importance of cultivating enduring respectful relationships among professionals and consumers and those who care about them—are identified and their relevance to the evolving recovery movement is discussed.     

Disrupted-in-Schizophrenia-1 SNPs and Susceptibility to Schizophrenia: Evidence from Malaysia

Objective

Even though the role of the DICS1 gene as a risk factor for schizophrenia is still unclear, there is substantial evidence from functional and cell biology studies that supports the connection of the gene with schizophrenia. The studies associating the DISC1 gene with schizophrenia in Asian populations are limited to East-Asian populations. Our study examined several DISC1 markers of schizophrenia that were identified in the Caucasian and East-Asian populations in Malaysia and assessed the role of rs2509382, which is located at 11q14.3, the mutual translocation region of the famous DISC1 translocation [t (1; 11) (p42.1; q14.3)].

Methods

We genotyped eleven single-neucleotide polymorphism (SNPs) within or related to DISC1 (rs821597, rs821616, rs4658971, rs1538979, rs843979, rs2812385, rs1407599, rs4658890, and rs2509382) using the PCR-RFLP methods.

Results

In all, there were 575 participants (225 schizophrenic patients and 350 healthy controls) of either Malay or Chinese ethnicity. The case-control analyses found two SNPs that were associated with schizophrenia [rs4658971 (p=0.030; OR=1.43 (1.35-1.99) and rs1538979-(p=0.036; OR=1.35 (1.02-1.80)] and rs2509382-susceptibility among the males schizophrenics [p=0.0082; OR=2.16 (1.22-3.81)]. This is similar to the meta-analysis findings for the Caucasian populations.

Conclusion

The study supports the notion that the DISC1 gene is a marker of schizophrenia susceptibility and that rs2509382 in the mutual DISC1 translocation region is a susceptibility marker for schizophrenia among males in Malaysia. However, the finding of the study is limited due to possible genetic stratification and the small sample size.