Early stage of radiological expertise modulates resting-state local coherence in the inferior temporal lobe

Background The visual system and its inherent functions undergo experience-dependent changes through the lifespan,enabling acquisition of new skills.Previous fMRI studies using tasks reported increased specialization in a number of cortical regions subserving visual expertise.Although ample studies focused on representation of long-term visual expertise in the brain,i.e.in terms of year,monthly-based early-stage representation of visual expertise remains unstudied.Given that spontaneous neuronal oscillations actively encode previous experience,we propose brain representations in the resting state is fundamentally important.Objective The current study aimed to investigate how monthly-based early-stage visual expertise are represented in the resting state using the expertise model of radiologists.Methods In particular,we investigated the altered local clustering pattern of spontaneous brain activity using regional homogeneity(ReHo).A cohort group of radiology interns(n=22)after one-month training in X-ray department and matched laypersons(n=22)were recruited after rigorous behavioral assessment.Results The results showed higher ReHo in the right hippocampus(HIP)and the right ventral anterior temporal lobe(vATL)(corrected by Alphasim correction,P<0.05).Moreover,ReHo in the right HIP correlated with the number of cases reviewed during intern radiologists’training(corrected by Alphasim correction,P<0.05).Conclusions In sum,our results demonstrated that the early stage of visual expertise is more concerned with stabilizing visual feature and domain-specific knowledge into long-term memory.The results provided novel evidence regarding how early-stage visual expertise is represented in the resting brain,which help further elaborate how human visual expertise is acquired.We propose that our current study may provide novel ideas for developing new training protocols in medical schools.

Altered regional homogeneity of prefrontal cortex in Parkinson's disease with mild cognitive impairment

Background:Mild cognitive impairment (MCI) is a common non-motor symptom of early Parkinson's disease (PD),but the neural mechanisms underlying it remain poorly understood.The aim of the present study was to investigate the characteristics of cognition-related brain activities in the PD patients with MCI.Methods:The brain fMRIs and cognition tests were acquired in 39 PD patients and 22 healthy controls (HC) from September 2013 to January 2015.The patients were divided into two groups:PD-MCI (n--18) and PD with normal cognition (PDNC,n =19).we used resting state fMRI and a regional homogeneity (ReHo) method to explore patterns of intrinsic brain activity in patients with PD-MCI as compared with PDNC subjects and HC.Results:Compared with the PDNC group,the PD-MCI group exhibited significantly increased ReHo in parts of the prefrontal cortex regions (e.g.right superior frontal gyrus,right middle frontal gyrus and orbitofrontal cortex).Compared to the HC group,a decrease of ReHo value in left thalamus was found in PD-MCI.However,this reduction was not found in the left thalamus of PDNC group,but in the above prefrontal regions (p ＜ 0.05,with Bonferroni correction).Conclusions:These results demonstrate that the ReHo of prefrontal cortex in resting state is changed in PD patients with MCI.The presence of MCI in PD may be attributed to abnormal regional activity in prefrontal cortex regions.

Reduced homotopic interhemispheric connectivity in psychiatric disorders:evidence for both transdiagnostic and disorder specific features

There is considerable interest in the significance of structural and functional connections between the two brain hemispheres in terms of both normal function and in relation to psychiatric disorders.In recent years,many studies have used voxel mirrored homotopic connectivity analysis of resting state data to investigate the importance of connectivity between homotopic regions in the brain hemispheres in a range of neuropsychiatric disorders.The current review summarizes findings fromthese voxel mirrored homotopic connectivity studies in individuals with autism spectrum disorder,addiction,attention deficit hyperactivity disorder,anxiety and depression disorders,and schizophrenia,aswell as disorders such as Alzheimer’s disease,mild cognitive impairment,epilepsy,and insomnia.Overall,other than attention deficit hyperactivity disorder,studies across psychiatric disorders report decreased homotopic resting state functional connectivity in the default mode,attention,salience,sensorimotor,social cognition,visual recognition,primary visual processing,and reward networks,which are often associated with symptom severity and/or illness onset/duration.Decreased homotopic resting state functional connectivity may therefore represent a transdiagnostic marker for general psychopathology.In terms of disorder specificity,the extensive decreases in homotopic resting state functional connectivity in autism differ markedly from attention deficit hyperactivity disorder,despite both occurring during early childhood and showing extensive co-morbidity.A pattern of more posterior than anterior regions showing reductions in schizophrenia is also distinctive.Going forward,more studies are needed to elucidate the functions of these homotopic functional connections in both health and disorder and focusing on associations with general psychopathology,and not only on disorder specific symptoms.

A Review of the Functional and Anatomical Default Mode Network in Schizophrenia

Schizophrenia is a severe mental disorder characterized by impaired perception, delusions, thought disorder, abnormal emotion regulation, altered motor function, and impaired drive. The default mode network （DMN）, since it was first proposed in 2001, has become a central research theme in neuropsychiatric disorders, including schizophrenia. In this review, first we define the DMN and describe its functional activity, functional and anatomical connectivity, heritability, and inverse correlation with the task positive network. Second, we review empirical studies of the anatomical and functional DMN, and anti-correlation between DMN and the task positive network in schizophrenia. Finally, we review preliminary evidence about the relationship between antipsychotic medications and regulation of the DMN, review the role of DMN as a treatment biomarker for this disease, and consider the DMN effects of individualized therapies for schizophrenia.