Multimodal Assessment of Neural Substrates in Computerized Cognitive Training: A Preliminary Study

BACKGROUND AND PURPOSE: Several studies have validated the clinical efficacy of computerized cognitive training applications. However, few studies have investigated the neural substrates of these training applications using simultaneous multimodal neuroimaging modalities. We aimed to determine the effectiveness of computerized cognitive training and corresponding neural substrates through a multimodal approach. METHODS: Ten patients with mild cognitive impairment (MCI), six patients with subjective memory impairment (SMI), and 10 normal controls received custom-developed computerized cognitive training in the memory clinic of a university hospital. All of the participants completed 24 sessions of computerized cognitive training, each lasting 40 minutes and performed twice weekly. They were assessed using neuropsychological tests (both computerized and conventional), electroencephalography, fluorodeoxyglucose positron-emission tomography (FDG-PET), volumetric magnetic resonance imaging (MRI), and diffusion-tensor imaging (DTI) at pre- and posttraining. RESULTS: The patients with MCI exhibited significant improvements in the trail-making test–black & white-B, and memory domain of the computerized cognitive assessment. Subjects with normal cognition exhibited significant improvements in scores in the language and attention-/psychomotor-speed domains. There were no significant changes in subjects with SMI. In the pre- and posttraining evaluations of the MCI group, FDG-PET showed focal activation in the left anterior insula and anterior cingulate after training. Volumetric MRI showed a focal increase in the cortical thickness in the rostral anterior cingulate. DTI revealed increased fractional anisotropy in several regions, including the anterior cingulate. CONCLUSIONS: The anterior cingulate and anterior insula, which are parts of the salience network, may be substrates for the improvements in cognitive function induced by computerized cognitive training.

Advance in Default Mode Network,Salience Network and Central Executive Network about Cognitive Function in Old Persons(review) / 中国康复理论与实践

@#A lot of researches indicate the relationship between cognitive impairment and functional connectivity of default mode network,salience network and central executive network.The changes of networks are various in different cognitive dys-function.It is important to apply resting state functional magnetic resonance in the old adults with cognitive dysfunction.

Neural correlates of hallucinations in bipolar disorder

Objective: Approximately one-half of all patients affected by bipolar disorder present with psychotic features on at least one occasion. Several studies have found that alterations in the activity of mesolimbic and prefrontal regions are related to aberrant salience in psychotic patients. The aim of the present study was to investigate the structural correlates of a history of hallucinations in a sample of euthymic patients with bipolar I disorder (BD-I). Methods: The sample consisted of 21 euthymic patients with BD-I and no comorbid axis I DSM-IV-TR disorders. Voxel based morphometry (VBM) was used to compare patients with and without a lifetime history of hallucinations. Preprocessing was performed using the Diffeomorphic Anatomical Registration through Exponentiated Lie Algebra (DARTEL) algorithm for VBM in SPM8. Images were processed using optimized VBM. Results: The main finding of the present study was a reduction in gray matter volume in the right posterior insular cortex of patients with BD-I and a lifetime history of hallucinations, as compared to subjects with the same diagnosis but no history of hallucinations. Conclusions: This finding supports the presence of abnormalities in the salience network in BD patients with a lifetime history of hallucinations. These alterations may be associated with an aberrant assignment of salience to the elements of one’s own experience, which could result in psychotic symptoms.

Does premotor connectivity on resting fMRI reflect stereotyped behavior in ASD children / 实用放射学杂志

Objective To probe the relationship between the connectivity of premotor area detected by resting state functional MRI and stereotyped behavior of ASD.Methods 39 children patients with ASD and 42 healthy controls with matched age,sex and IQ were recruited.All the 81 subjects performed scaling with behavior scale index and underwent resting-state fMRI scans.After the fMRI data precession,the premotors in left and right sides were selected as ROI seeds to perform functional connectivity.Results Compared with healthy controls,children patients showed significant increased connectivity between the left premotor area and posterior cingulate cortex,as well as decreased functional connectivity between the left premotor area and the left insula.In addition, a negative linear correlation was showed between the connectivity of the left premotor and the insula and the behavioral scores.Con-clusion Imbalanced premotor functional connectivity may be one possible mechanism of stereotyped behavior of ASD,representing an attention deficit and/or impaired sensory perception to the external salient stimuli.

Aberrant resting-state functional connectivity of default mode and salience network in patients with schizo-phrenia / 中国神经精神疾病杂志

Objective To explore the feature of functional connectivity of default mode network (DMN) and salience network (SN) in unmedicated schizophrenia patients during a resting state by functional magnetic resonance imaging (fM-RI). Methods The SPM8 and DPARSFA softwares combined with independent component analysis (ICA) were used to in-vestigate functional connectivity (FC) of the DMN and SN in 27 unmedicated patients with schizophrenia and 27 age-and gender-matched healthy controls. Results Concerning the DMN, patients with schizophrenia showed decreased FC in right inferior frontal gyrus , right precuneus(unadjusted P<0.05)and increased FC in right middle cingulate gyrus, left middle frontal gyrus(unadjusted P<0.05). With regard to the SN, patients showed reduced connectivity in left inferior frontal gyrus, right inferior frontal gyrus, left anterior cingulate, left postcentral gyrus(unadjusted P<0.05)and increased connectivity in left superior temporal gyrus(unadjusted P<0.05). Correlation analyses showed that the increased FC of left superior temporal gyrus significantly correlated with PANSS-positive symptoms(r=0.568,P=0.002)and decreased FC of right precuneus significantly negatively correlated with delusion symptom(r=-0.458,P=0.016). Conclusion This study provides evidence for resting state functional abnormalities of DMN and SN in unmedicated schizophrenia patients. These aberrant function connectivities in some brain regions of the two networks could be a source of abnormal introspectively-oriented mental actives.