ABSTRACT
BACKGROUND: There is growing evidence for the use of acceptance-commitment therapy (ACT) for the treatment of obsessive-compulsive disorder (OCD). However, few fully implemented ACT have been conducted on the neural mechanisms underlying its effect on OCD. Thus, this study aimed to elucidate the neural correlates of ACT in patients with OCD using task-based and resting-state functional magnetic resonance imaging (fMRI). METHODS: Patients with OCD were randomly assigned to the ACT (n = 21) or the wait-list control group (n = 21). An 8-week group-format ACT program was provided to the ACT group. All participants underwent an fMRI scan and psychological measurements before and after 8 weeks. RESULTS: Patients with OCD showed significantly increased activation in the bilateral insula and superior temporal gyri (STG), induced by the thought-action fusion task after ACT intervention. Further psycho-physiological interaction analyses with these regions as seeds revealed that the left insular-left inferior frontal gyrus (IFG) connectivity was strengthened in the ACT group after treatment. Increased resting-state functional connectivity was also found in the posterior cingulate cortex (PCC), precuneus, and lingual gyrus after ACT intervention Most of these regions showed significant correlations with ACT process measures while only the right insula was correlated with the obsessive-compulsive symptom measure. CONCLUSIONS: These findings suggest that the therapeutic effect of ACT on OCD may involve the salience and interoception processes (i.e. insula), multisensory integration (i.e. STG), language (i.e. IFG), and self-referential processes (i.e. PCC and precuneus). These areas or their interactions could be important for understanding how ACT works psychologically.
Subject(s)
Magnetic Resonance Imaging , Obsessive-Compulsive Disorder , Humans , Magnetic Resonance Imaging/methods , Brain Mapping/methods , Prefrontal Cortex , Obsessive-Compulsive Disorder/diagnostic imaging , Obsessive-Compulsive Disorder/therapy , Gyrus Cinguli/diagnostic imaging , Brain/diagnostic imagingABSTRACT
Many studies have been conducted on the use of ultra-small iron oxide nanoparticles (USIONs) (d < 3 nm) as potential positive magnetic resonance imaging (MRI)-contrast agents (CAs); however, there is dearth of research on clustered USIONs. In this study, nearly monodispersed clustered USIONs were synthesized using a simple two-step one-pot polyol method. First, USIONs (d = 2.7 nm) were synthesized, and clustered USIONs (d = 27.9 nm) were subsequently synthesized through multiple cross-linking of USIONs with poly(acrylic acid-co-maleic acid) (PAAMA) polymers with many -COOH groups. The clustered PAAMA-USIONs exhibited very weak ferromagnetism owing to the magnetic interaction between superparamagnetic USIONs; this was evidenced by their appreciable r1= 3.9 sâ1mMâ1and high r2/r1ratio of 14.6. Their ability to function as a dual-modal T1/T2MRI-CA in T1-weighted MRI was demonstrated when they simultaneously exhibited positive and negative contrasts in T1-weighted MRI of tumor model mice after intravenous injection. They displayed positive contrasts at the kidneys, bladder, heart, and aorta and negative contrasts at the liver and tumor. .
ABSTRACT
Spinal cord injury (SCI) can cause motor, sensory, and autonomic dysfunctions and may affect the cerebral functions. However, the mechanisms of plastic changes in the brain according to SCI severity remain poorly understood. Therefore, in the current study, we compared the brain activity of the entire neural network according to severity of SCI using fractional amplitude of low-frequency fluctuations (fALFF) analysis in resting-state functional magnetic resonance imaging (rs-fMRI). A total of 59 participants were included, consisting of 19 patients with complete SCI, 20 patients with incomplete SCI, and 20 healthy individuals. Their motor and sensory functions were evaluated. The rs-fMRI data of low-frequency fluctuations were analyzed based on fALFF. Differences in fALFF values among complete-SCI patients, incomplete-SCI patients, and healthy controls were assessed using ANOVA. Then post hoc analysis and two-sample t-tests were conducted to assess the differences between the three groups. Pearson correlation analyses were used to determine correlations between clinical measures and the z-score of the fALFF in the SCI groups. Patients with SCI (complete and incomplete) showed lower fALFF values in the superior medial frontal gyrus than the healthy controls, and were associated with poor motor and sensory function (p < .05). Higher fALFF values were observed in the putamen and thalamus, and were negatively associated with motor and sensory function (p < .05). In conclusion, alterations in the neural activity of the motor- and sensory-related networks of the brain were observed in complete-SCI and incomplete-SCI patients. Moreover, plastic changes in these brain regions were associated with motor and sensory function.
Subject(s)
Brain/physiopathology , Magnetic Resonance Imaging/methods , Nerve Net/physiopathology , Spinal Cord Injuries/physiopathology , Adult , Aged , Brain/diagnostic imaging , Brain Mapping , Female , Humans , Male , Middle Aged , Nerve Net/diagnostic imaging , Severity of Illness Index , Spinal Cord Injuries/diagnostic imagingABSTRACT
BACKGROUND: Cognitive theories of obsessive-compulsive disorder (OCD) stress the importance of dysfunctional beliefs in the development and maintenance of the disorder. However, a neurobiological understanding of these cognitive models, including thought-action fusion (TAF), is surprisingly lacking. Thus, this functional magnetic resonance imaging study aimed to investigate whether altered functional connectivity (FC) is associated with the TAF paradigm in OCD patients. METHODS: Forty-one OCD patients and 47 healthy controls (HCs) participated in a functional magnetic resonance imaging study using a TAF task, in which they were asked to read the name of a close or a neutral person in association with positive and negative statements. RESULTS: The conventional TAF condition (negative statements/close person) induced significant FC between the regions of interest (ROIs) identified using multivoxel pattern analysis and the visual association areas, default mode network subregions, affective processing, and several subcortical regions in both groups. Notably, sparser FC was observed in OCD patients. Further analysis confined to the cortico-striato-thalamo-cortical (CSTC) and affective networks demonstrated that OCD patients exhibited reduced ROI FC with affective regions and greater ROI FC with CSTC components in the TAF condition compared to HCs. Within the OCD patients, middle cingulate cortex-insula FC was correlated with TAF and responsibility scores. CONCLUSIONS: Our TAF paradigm revealed altered context-dependent engagement of the CSTC and affective networks in OCD patients. These findings suggest that the neurobiology of cognitive models corresponds to current neuroanatomical models of OCD. Further, they elucidate the underlying neurobiological mechanisms of OCD at the circuit-based level.
Subject(s)
Obsessive-Compulsive Disorder , Humans , Obsessive-Compulsive Disorder/diagnostic imaging , Magnetic Resonance Imaging/methods , Gyrus Cinguli/diagnostic imagingABSTRACT
Changes in the brain with age can provide useful information regarding an individual's chronological age. studies have suggested that functional connectomes identified via resting-state functional magnetic resonance imaging (fMRI) could be a powerful feature for predicting an individual's age. We applied connectome-based predictive modeling (CPM) to investigate individual chronological age predictions via resting-state fMRI using open-source datasets. The significant feature for age prediction was confirmed in 168 subjects from the Southwest University Adult Lifespan Dataset. The higher contributing nodes for age production included a positive connection from the left inferior parietal sulcus and a negative connection from the right middle temporal sulcus. On the network scale, the subcortical-cerebellum network was the dominant network for age prediction. The generalizability of CPM, which was constructed using the identified features, was verified by applying this model to independent datasets that were randomly selected from the Autism Brain Imaging Data Exchange I and the Open Access Series of Imaging Studies 3. CPM via resting-state fMRI is a potential robust predictor for determining an individual's chronological age from changes in the brain.
Subject(s)
Connectome , Adult , Aging , Brain/diagnostic imaging , Connectome/methods , Humans , Magnetic Resonance Imaging/methods , Nerve Net/diagnostic imagingABSTRACT
The study of ultra-small paramagnetic gadolinium oxide (Gd2O3) nanoparticles (NPs) as in vivo positive (T1) magnetic resonance imaging (MRI) contrast agents is one of the most attractive fields in nanomedicine. The performance of the Gd2O3 NP imaging agents depends on the surface-coating materials. In this study, poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was used as a surface-coating polymer. The PMVEMA-coated paramagnetic ultra-small Gd2O3 NPs with an average particle diameter of 1.9 nm were synthesized using the one-pot polyol method. They exhibited excellent colloidal stability in water and good biocompatibility. They also showed a very high longitudinal water proton spin relaxivity (r1) value of 36.2 s-1mM-1 (r2/r1 = 2.0; r2 = transverse water proton spin relaxivity) under a 3.0 tesla MR field which is approximately 10 times higher than the r1 values of commercial molecular contrast agents. High positive contrast enhancements were observed in in vivo T1 MR images after intravenous administration of the NP solution sample, demonstrating its potential as a T1 MRI contrast agent.
Subject(s)
Coated Materials, Biocompatible , Gadolinium , Magnetic Resonance Imaging , Maleic Anhydrides , Metal Nanoparticles , Polyvinyls , Animals , Cell Line, Tumor , Cell Survival , Chemical Phenomena , Coated Materials, Biocompatible/chemistry , Contrast Media , Gadolinium/chemistry , Magnetic Resonance Imaging/methods , Maleic Anhydrides/chemistry , Metal Nanoparticles/chemistry , Metal Nanoparticles/ultrastructure , Mice , Molecular Structure , Particle Size , Polyvinyls/chemistry , Signal-To-Noise Ratio , Spectrum AnalysisABSTRACT
BACKGROUND: Thought-action fusion (TAF) represents an individual's belief that a thought is like action. Inflated TAF has been considered a central mechanism for developing obsessive thoughts. However, the neural mechanisms underlying TAF are yet unknown. METHODS: We recruited 32 healthy men to participate in a functional magnetic resonance imaging (fMRI) study. Whereas inside the 3T MRI scanner, participants were asked to read negative statements describing the expectation of bad events associated with close persons (CPs condition) or neutral persons (NPs condition). They also completed the assessment of TAF and obsessive-compulsive (OC) symptoms. RESULTS: Both CP and NP conditions commonly activated the lingual gyrus, caudate nucleus, precuneus, and several areas of the frontal cortex. Importantly, many of these regions were positively correlated with measures of OC symptoms, especially for the CP condition. The CP condition showed higher activation in the insula and temporal gyrus than the NP condition. In contrast, the NP condition evoked higher activation in regions associated with mentalizing, such as the medial prefrontal cortex and dorsal anterior cingulate cortex than the CP condition. CONCLUSIONS: We introduced and validated a TAF-induction paradigm suitable for fMRI studies and characterized the neural circuits engaged during this paradigm. Further studies using this task may help us to better understand how dysfunctions in TAF neural processing may contribute to psychiatric conditions such as obsessive-compulsive disorder.
Subject(s)
Brain Mapping/methods , Brain/physiopathology , Magnetic Resonance Imaging/methods , Obsessive-Compulsive Disorder/physiopathology , Thinking/physiology , Adult , Brain/diagnostic imaging , Humans , Male , Republic of Korea , Young AdultABSTRACT
BACKGROUND: Mixed reality (MR) technology, which combines the best features of augmented reality and virtual reality, has recently emerged as a promising tool in cognitive rehabilitation therapy. OBJECTIVE: To investigate the effectiveness of an MR-based cognitive training system for individuals with mild cognitive impairment (MCI). METHODS: Twenty-one individuals aged 65 years and older who had been diagnosed with MCI were recruited for this study and were divided into two groups. Participants in the MR group (n=10, aged 70.5±4.2 years) received 30 minutes of training 3 times a week for 6 weeks using a newly developed MR-based cognitive training system. Participants in the control group (n=11, aged 72.6±5.3 years) received the same amount of training using a conventional computer-assisted cognitive training system. Both groups took the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K) both before and after intervention. To determine the effect of the intervention on cognitive function, we compared the difference in each group's CERAD-K scores. RESULTS: There was a statistically significant interaction between intervention (MR group vs control group) and time (before vs after intervention) as assessed by the Constructional Recall Test. The individuals with MCI who participated in the MR training showed significantly improved performance in visuospatial working memory compared with the individuals with MCI who participated in the conventional training. CONCLUSION: An MR-based cognitive training system can be used as a cognitive training tool to improve visuospatial working memory in individuals with MCI.
Subject(s)
Cognition Disorders/diagnosis , Neuropsychological Tests/standards , Aged , Aged, 80 and over , Augmented Reality , Cognitive Dysfunction/diagnosis , Female , Humans , Male , Pilot Projects , Virtual RealityABSTRACT
D-glucuronic acid-coated ultrasmall chromium oxide (Cr2O3) nanoparticles were synthesized by a one-pot polyol method and their relaxometric and optical properties were investigated. The as-synthesized D-glucuronic acid-coated nanoparticles were amorphous owing to ultrasmall particle diameters (davg = 2.0 nm), whereas orthorhombic Cr2O3 nanoparticles with two size groups (davg = 3.6 and 5.7 nm) were observed after thermogravimetric analysis (900 °C) as a result of particle growth. The nanoparticles exhibited size-dependent UV-visible absorption maxima at 238, 274, and 372 nm with increasing particle diameter, corresponding to band gaps of 5.13, 4.45, and 3.28 eV, respectively. D-glucuronic acid-coated ultrasmall Cr2O3 nanoparticles revealed low water proton relaxivities of r1 = 0.05 s-1mM-1 and r2 = 0.20 s-1mM-1, consistent with the antiferromagnetic property of Cr2O3. They showed good biocompatibility up to 500 µM of Cr.
ABSTRACT
Mixed Zn(II)/Gd(III) oxide nanoparticles (~8 mole%Zn) with d(avg) of 2.1 nm were synthesized. The D-glucuronic acid coated Zn(II)/Gd(III) oxide nanoparticles showed a longitudinal water proton relaxivity (r1) of 12.3 s⻹mM⻹ with r2/r1 = 1.1, corresponding to an ideal condition for T1 MRI contrast agent. We attribute this to reduced magnetization of the mixed nanoparticles owing to non-magnetic Zn in the nanoparticles. Their effectiveness as a T1 MRI contrast agent was confirmed by acquiring In Vivo T1 MR images of a mouse after intravenous injection.
ABSTRACT
BACKGROUND: Glutathione (GSH) is a crucial antioxidant in the human brain. Although proton magnetic resonance spectroscopy (MRS) using the MEscher-GArwood Point RESolved Spectroscopy (MEGA-PRESS) sequence is highly recommended, limited literature has measured cortical GSH using this method in major psychiatric disorders. METHODS: By combining MRS using the MEGA-PRESS and resting-state functional magnetic resonance imaging, we quantified brain GSH and glutamate in the medial prefrontal cortex (mPFC) and precuneus and explore relationships between the GSH levels and intrinsic neuronal activity as well as clinical symptoms among the three groups of healthy controls (HCs, N=30), major depressive disorder (MDD, N=28), and obsessive-compulsive disorder (OCD, N=28). RESULTS: GSH concentrations were lower in both the mPFC and precuneus in both the MDD and OCD groups compared to HCs. In HCs, positive correlations were noted between the GSH and glutamate levels, and between GSH and fractional amplitude of low-frequency fluctuations (fALFF) in both regions. However, while these correlations were absent in both patient groups, they showed a weak positive correlation between glutamate and fALFF values. Moreover, GSH levels negatively correlated with depressive and compulsive symptoms in MDD and OCD, respectively. CONCLUSIONS: These findings suggest that reduced GSH levels and an imbalance between GSH and glutamate could increase oxidative stress and alter neurotransmitter signaling, leading to disruptions in GSH-related neurochemical-neuronal coupling and psychopathologies across MDD and OCD. Understanding these mechanisms could provide valuable insights into the underlying processes of these disorders, potentially becoming a springboard for future directions and advancing our knowledge of their neurobiological foundations.
ABSTRACT
Magnetite nanoparticles (Fe3O4 NPs) have been intensively investigated because of their potential biomedical applications due to their high saturation magnetization. In this study, core-shell Fe3O4@C NPs (core = Fe3O4 NPs and shell = amorphous carbons, davg = 35.1 nm) were synthesized in an aqueous solution. Carbon coating terminated with hydrophilic -OH and -COOH groups imparted excellent biocompatibility and hydrophilicity to the NPs, making them suitable for biomedical applications. The Fe3O4@C NPs exhibited ideal relaxometric properties for T2 magnetic resonance imaging (MRI) contrast agents (i.e., high transverse and negligible longitudinal water proton spin relaxivities), making them exclusively induce only T2 relaxation. Their T2 MRI performance as contrast agents was confirmed in vivo by measuring T2 MR images in mice before and after intravenous injection.
ABSTRACT
OBJECTIVE: Although cognitive models of obsessive-compulsive disorder (OCD) fall into two categories: cognitive deficit models and dysfunctional belief models, these approaches have their own ways and have hardly been reconciled. Therefore, this study aimed to investigate the potential relationships between cognitive deficit (using the Wisconsin Card Sorting Task, WCST) and dysfunctional belief (measured by scales of dysfunctional beliefs) mediated by neural activity in OCD patients. METHODS: Thirty OCD patients and 30 healthy participants performed the WCST condition and a baseline MATCH condition during the 3T-functional magnetic resonance imaging (fMRI) acquisition. RESULTS: Engagement of additional frontoparietal networks with poorer performance of WCST was found during the fMRI scan in OCD patients. Selected regions of interest from activated regions have positive relationships with dysfunctional beliefs and with the unacceptable thoughts symptom dimension in the OCD group. CONCLUSION: Findings suggest that alteration in frontoparietal networks related to cognitive deficits can be associated with dysfunctional beliefs while performing conventional neurocognitive tasks and this association with dysfunctional beliefs may be pronounced in the unacceptable thoughts domain-dominant OCD patients.
ABSTRACT
Contralateral C7 (CC7) nerve transfer surgery was shown to significantly improve the spasticity condition and the motor function of paralyzed arms. However, the involvement of the white matter tract in the recovery process is not well established. We here investigated the possible biologic explanation for this phenomenon. A 62-year-old female patient, who suffered from spastic hemiparesis due to intracranial hemorrhage, underwent CC7 transfer surgery 13 years after the initial stroke event. Six months after the surgery, the patient's Modified Ashworth Scale and Fugl-Myere score improved, even though no specific rehabilitation programs were applied. Diffusion tensor imaging (DTI) was performed before and 6 months after the surgery. The pre-surgery DTI showed both ipsilesional and contralesional CST from the cerebral peduncles to the cortices. After surgery, however, only the contralesional CST was observed. In conclusion, functional alterations of the brain white matter tract after CC7 nerve transfer surgery possibly provided a neurophysiological substrate for ameliorating the spasticity and improving the motor function in a spastic hemiplegia patient.
Subject(s)
Hemiplegia/surgery , Nerve Transfer/methods , Pyramidal Tracts , Spinal Nerves/transplantation , White Matter , Diffusion Tensor Imaging , Female , Humans , Middle Aged , Pyramidal Tracts/physiopathology , White Matter/physiopathologyABSTRACT
OBJECTIVE: Thought-action fusion (TAF), one of the most-studied dysfunctional beliefs in obsessive-compulsive disorder, represents an individual's belief that his/her thoughts directly influence events. TAF belief types are divided into personal thoughts relating to positive (positive TAF) and negative outcomes (negative TAF). However, the neural mechanisms underlying both aspects of the TAF response remain elusive. METHODS: This functional magnetic resonance imaging study aimed to investigate the neural circuits related to positive and negative TAF and their relationships with psychological measures. Thirty-one healthy male volunteers participated in a modified TAF task wherein they were asked to read the name of a close person embedded in positive statements (PS) or negative statements (NS). RESULTS: Conjunction analysis revealed activation of the fusiform and lingual gyri, midcingulate and superior medial frontal gyri, inferior orbitofrontal gyrus, and temporoparietal junction. The NS > PS comparison showed additional activation in the precuneus and medial prefrontal cortex, superior frontal gyrus, insula, globus pallidus, thalamus, and midbrain. Precuneus activity was associated with the TAF score among these areas. Moreover, activity in the inferior orbitofrontal gyrus, insula, superior, middle and medial frontal gyri, globus pallidus, inferior parietal lobule, and precuneus was associated with dimensional obsessive-compulsive scores. In contrast, the PS > NS comparison revealed no significant activation. CONCLUSION: These results suggest that negative TAF, relative to positive TAF, recruits additional regions for self-referential processing, salience, and habitual responding, which may contribute to the activation of the belief that a negative thought increases the probability of that negative outcome.
ABSTRACT
Thought-action fusion (TAF) is a tendency of individuals to establish causal relations between their own thoughts and external reality. TAF can lead to maladaptive behaviors typically observed in obsessional thoughts. However, neural mechanisms underlying TAF are still unknown. In this study, 38 healthy men were informed that MR signals were able to detect thoughts of the word 'apple' and that this recognition could result in the administration of electrical shocks to a person outside the scanner. During MR acquisition, they were asked to suppress or not suppress the thought of 'apple' while sham electrical shocks were or were not administered to the other person. The main effect of the sham administration of electrical shock to another person was shown in the bilateral lingual gyri, fusiform gyri, and middle occipital cortices (FDR corrected p < 0.05). Also, fusiform gyrus, lingual gyrus, and middle occipital cortex activity correlated with scores of guilty feeling only when participants consciously tried to think of apple as less as possible. Our study demonstrates that visual association areas may play primary roles in TAF. The simple belief and visual imagery that one's thought may lead to someone's injury activated visual areas of the brain where, in turn, brain activity is associated with feelings of guilt.
Subject(s)
Brain Mapping , Magnetic Resonance Imaging , Adult , Brain/diagnostic imaging , Humans , Male , Occipital Lobe , Temporal LobeABSTRACT
Maltreatment experiences alter brain development associated with emotion processing, and dysregulation of emotion may trigger mental health problems in maltreated people. However, studies revealing alterations in brain networks during cognitive reappraisal in victims of maltreatment are strikingly insufficient. In this study, 27 healthy subjects were recruited. The maltreatment experiences and positive reappraisal abilities were measured using the Childhood Trauma Questionnaire-Short Form (CTQ-SF) and Cognitive Emotion Regulation Questionnaire (CERQ), respectively. A cognitive reappraisal task using the International Affective Picture System (IAPS) was designed for functional magnetic resonance imaging (fMRI) experiments. Cognitive reappraisal induced more activities in the bilateral inferior parietal lobes and bilateral middle temporal gyri compared to the condition of "look" (false discovery rate (FDR) corrected p < 0.05). Furthermore, the left inferior parietal lobe and right middle temporal gyrus functionally interacted with components of the default mode network, including the precuneus and the posterior cingulate cortex. In residual analyses after controlling for age and depressive symptoms, the bilateral inferior parietal and middle temporal activities exhibited positive correlations with cognitive reappraisal abilities (all ps < 0.05), and emotional maltreatment experiences were negatively correlated with the left inferior parietal cortex, bilateral middle temporal cortex activities, and left inferior parietal lobe-posterior cingulate cortex connectivity (all ps < 0.05). We found that semantic networks were significant to cognitive reappraisal, especially reinterpretation, and negative effects of emotional maltreatment experiences on semantic network activities.
Subject(s)
Brain Mapping , Semantic Web , Brain/diagnostic imaging , Cognition , Emotions , Humans , Magnetic Resonance ImagingABSTRACT
Polyacrylic acid (PAA)-coated lanthanide oxide (Ln2O3) nanoparticles (NPs) (Ln = Tb and Ho) with high colloidal stability and good biocompatibility were synthesized, characterized, and investigated as a new class of negative (T2) magnetic resonance imaging (MRI) contrast agents at high MR fields. Their r2 values were appreciable at a 3.0 T MR field and higher at a 9.4 T MR field, whereas their r1 values were negligible at all MR fields, indicating their exclusive induction of T2 relaxations with negligible induction of T1 relaxations. Their effectiveness as T2 MRI contrast agents at high MR fields was confirmed from strong negative contrast enhancements in in vivo T2 MR images at a 9.4 T MR field after intravenous administration into mice tails.
ABSTRACT
In this study, hydrophilic and biocompatible chitosan oligosaccharide lactate (COL)-coated ultra-small gadolinium oxide nanoparticles (NPs) were synthesized through a one-pot polyol method and characterized by various experimental techniques. The In Vitro cellular cytotoxicity assay indicated that the COL-coated gadolinium oxide NPs were non-toxic up to 500 µM Gd. In addition, their water proton spin relaxivities (i.e., r1 and r2) were estimated to be 13.0 and 27.0 s-1mM-1, respectively, which are higher than those of commercial magnetic resonance imaging (MRI) contrast agents. The application potential of the solution sample as a T1 MRI contrast agent was demonstrated In Vitro by measuring map images in which dose-dependent contrast enhancements were observed.
Subject(s)
Chitosan , Nanoparticles , Chitosan/toxicity , Contrast Media/toxicity , Gadolinium , Lactic Acid , Magnetic Resonance Imaging , Nanoparticles/toxicity , OligosaccharidesABSTRACT
Mild cognitive impairment (MCI) is defined as an intermediate state of cognitive alteration between normal aging and dementia. In this study, we performed a functional network connectivity analysis using resting-state functional magnetic resonance imaging to investigate the association between changes in functional connectivity in the brain and the improvement in cognitive abilities after cognitive training. A computerized cognitive training program was used to improve the abilities of fifteen participants with MCI. The cognitive training program (Comcog), which consists of three weekly sessions totaling 90 min, was conducted with all participants over six weeks. The cognitive abilities before (pre-Comcog) and after (post-Comcog) the cognitive training process were measured using a neurocognitive function test. After the Comcog, the participants enhanced their visual and verbal memories, attention, and visuo-motor coordination. The functional connectivity between cingulo-opercular (CON) and default mode (DMN) showed significant improvements after Comcog training. Therefore, our study suggests that cognitive training may improve the cognitive abilities of participants. This improvement was associated with an increase in the functional connectivity between DMN and CON. The increase in functional connectivity after cognitive training was specifically associated with overall cognitive functions, including executive, memory, decision-making, and motivational functions.