Bilateral Inferior Parietal Lobule Research Articles

Gray Matter Volume Differences Between More Versus Less Resilient Adults with Chronic Musculoskeletal Pain: A Voxel-based Morphology Study

Resilience, a personality construct that reflects capacities to persevere, maintain a positive outlook and/or thrive despite ongoing stressors, has emerged as an important focus of research on chronic pain (CP). Although behavior studies have found more resilient persons with CP experience less pain-related dysfunction than less resilient cohorts do, the presence and nature of associated brain structure differences has received scant attention. To address this gap, we examined gray matter volume (GMV) differences between more versus less resilient adults with chronic musculoskeletal pain. Participants (75 women, 43 men) were community-dwellers who reported ongoing musculoskeletal pain for at least three months. More (n = 57) and less (n = 61) resilient subgroups, respectively, were identified on the basis of scoring above and below median scores on two validated resilience questionnaires. Voxel-based morphology (VBM) undertaken to examine resilience subgroup differences in GMV indicated more resilient participants displayed significantly larger GMV in the (1) bilateral precuneus, (2) left superior and inferior parietal lobules, (3) orbital right middle frontal gyrus and medial right superior frontal gyrus, and (4) bilateral median cingulate and paracingulate gyri, even after controlling for subgroup differences on demographics and measures of pain-related distress. Together, results underscored the presence and nature of specific GMV differences underlying subjective reports of more versus less resilient responses to ongoing musculoskeletal pain.

Brain Resources: How Semantic Cueing Works in Mild Cognitive Impairment due to Alzheimer's Disease (MCI-AD).

Semantic cues in the Free and Cued Selective Reminding Test (FCRST) play a key role in the neuropsychological diagnosis of Amnesic Mild Cognitive Impairment due to Alzheimer’s Disease (MCI-AD); however, the neural bases of their impact of recall abilities are only partially understood. Here, we thus decided to investigate the relationships between brain metabolism and the FCSRT Index of Sensitivity of Cueing (ISC) in patients with MCI-AD and in healthy controls (HC). Materials: Thirty MCI-AD patients (age: 74.7 ± 5.7 years; education: 9.6 ± 4.6 years, MMSE score: 24.8 ± 3.3, 23 females) and seventeen HC (age: 66.5 ± 11.1 years; education: 11.53 ± 4.2 years, MMSE score: 28.4 ± 1.14, 10 females) who underwent neuropsychological evaluation and brain F-18 fluorodeoxyglucose Positron Emission Tomography (FDG-PET) were included in the study. Results: ISC was able to differentiate HC from MCI-AD subjects as shown by a ROC analysis (AUC of 0.978, effect size Hedges’s g = 2.89). MCI-AD subjects showed significant hypometabolism in posterior cortices, including bilateral inferior Parietal Lobule and Precuneus and Middle Temporal gyrus in the left hemisphere (VOI-1) compared to HC. ISC was positively correlated with brain metabolism in a single cluster (VOI-2) spanning the left prefrontal cortex (superior frontal gyrus) and anterior cingulate cortex (ACC) in the patient group (R2 = 0.526, p < 0.001), but not in HC. Mean uptake values of VOI-2 did not differ between HC and MCI-AD. The structural connectivity analysis showed that VOI-2 is connected with the temporal pole, the cingulate gyrus and the posterior temporal cortices in the left hemisphere. Conclusion: In MCI-AD, the relative preservation of frontal cortex metabolic levels and their correlation with the ISC suggest that the left frontal cortices play a significant role in maintaining a relatively good memory performance despite the presence of posterior hypometabolism in MCI-AD.

A case suspected of Alzheimer type dementia showing multimodal (face and voice) person recognition disorder from face and voice

A 90-year-old woman presented with a multimodal (face and voice) person recognition disorder. Although she had moderate general cognitive impairment, her visual cognitive capacity, other than face recognition, was well preserved. She could identify the faces and voices of family members but could not recall the names and voices of relatives whom she met infrequently, famous individuals, or the medical staff. She could remember the first names and some information about prominent individuals when supplied with their surnames. Therefore, we thought that her person-specific semantic memory was intact but she was unable to access it through their faces and voices. MRI revealed predominantly right-sided bilateral anterior temporal lobe and hippocampal atrophy. SPECT images showed decreased blood flow in the bilateral anterior temporal lobes and inferior parietal lobule (heavily and predominantly right-sided), right posterior cingulate gyrus, and precuneus. Progressive person recognition disorder or prosopagnosia has been considered a right temporal variant of frontotemporal lobar degeneration because abnormal behaviors and psychiatric symptoms frequently coexist. However, no such symptoms were observed in this case, therefore we suspected dementia of the Alzheimer type.

Neurologic Factors in Patients with Vascular Mild Cognitive Impairment Based on fMRI

This study focused on the application of functional magnetic resonance imaging and neuropsychology in diagnosis of vascular mild cognitive impairment (MCI) and the exploration of its relevant factors. The study enrolled 28 patients with vascular MCI in an observation group and 30 healthy individuals in a control group. All patients underwent magnetic resonance imaging. An automatic segmentation algorithm based on graph theory was adopted to process the images. Age, sex, disease course, Montreal Cognitive Assessment score, regional homogeneity, and amplitude of low-frequency fluctuation levels were recorded. There were no significant differences in age, gender, and course of disease between the observation group and the control group (P > 0.05). The level of regional homogeneity in the left posterior cerebellum in the observation group was significantly higher than that in the control group (P < 0.05).The regional homogeneity level of bilateral cingulate cortex was negatively correlated with Montreal Cognitive Assessment score (P < 0.05). The amplitude of low-frequency fluctuation of bilateral inferior parietal lobe, parietal lobe, and prefrontal lobe in the observation group was significantly lower than that in the control group, and the amplitude of low-frequency fluctuation of bilateral anterior cingulate gyrus, superior medial frontal gyrus, orbital frontal gyrus, right middle frontal gyrus, and right auxiliary motor area was higher than that in the control group (P < 0.05). Heart disease, such as myocardial infarction and atrial fibrillation, is a high risk factor for vascular MCI. Functional magnetic resonance imaging combined with an automatic segmentation algorithm can noninvasively observe the changes of a patient's brain tissue, which can be used in the recognition of vascular MCI. The global network attributes of patients with depression tend to be more randomized and have stronger resilience under targeted attacks.

Integration of Simultaneous Resting-State Electroencephalography, Functional Magnetic Resonance Imaging, and Eye-Tracker Methods to Determine and Verify Electroencephalography Vigilance Measure.

Background/Introduction: Concurrent electroencephalography and resting-state functional magnetic resonance imaging (rsfMRI) have been widely used for studying the (presumably) awake and alert human brain with high temporal/spatial resolution. Although rsfMRI scans are typically collected while individuals are instructed to focus their eyes on a fixated cross, objective and verified experimental measures to quantify degree of vigilance are not readily available. Electroencephalography (EEG) is the modality extensively used for estimating vigilance, especially during eyes-closed resting state. However, pupil size measured using an eye-tracker device could provide an indirect index of vigilance. Methods: Three 12-min resting scans (eyes open, fixating on the cross) were collected from 10 healthy control participants. We simultaneously collected EEG, fMRI, physiological, and eye-tracker data and investigated the correlation between EEG features, pupil size, and heart rate. Furthermore, we used pupil size and EEG features as regressors to find their correlations with blood-oxygen-level-dependent fMRI measures. Results: EEG frontal and occipital beta power (FOBP) correlates with pupil size changes, an indirect index for locus coeruleus activity implicated in vigilance regulation (r = 0.306, p < 0.001). Moreover, FOBP also correlated with heart rate (r = 0.255, p < 0.001), as well as several brain regions in the anticorrelated network, including the bilateral insula and inferior parietal lobule. Discussion: In this study, we investigated whether simultaneous EEG-fMRI combined with eye-tracker measurements can be used to determine EEG signal feature associated with vigilance measures during eyes-open rsfMRI. Our results support the conclusion that FOBP is an objective measure of vigilance in healthy human subjects. Impact statement We revealed an association between electroencephalography frontal and occipital beta power (FOBP) and pupil size changes during an eyes-open resting state, which supports the conclusion that FOBP could serve as an objective measure of vigilance in healthy human subjects. The results were validated by using simultaneously recorded heart rate and functional magnetic resonance imaging (fMRI). Interestingly, independently verified heart rate changes can also provide an easy-to-determine measure of vigilance during resting-state fMRI. These findings have important implications for an analysis and interpretation of dynamic resting-state fMRI connectivity studies in health and disease.

Glutamatergic modulation of auditory cortex connectivity with attentional brain networks in unpredictable perceptual environment

In a stable environment the brain can minimize processing required for sensory input by forming a predictive model of the surrounding world and suppressing neural response to predicted stimuli. Unpredicted stimuli lead to a prediction error signal propagation through the perceptual network, and resulting adjustment to the predictive model. The inter-regional plasticity which enables the model-building and model-adjustment is hypothesized to be mediated via glutamatergic receptors. While pharmacological challenge studies with glutamate receptor ligands have demonstrated impact on prediction-error indices, it is not clear how inter-individual differences in the glutamate system affect the prediction-error processing in non-medicated state. In the present study we examined 20 healthy young subjects with resting-state proton MRS spectroscopy to characterize glutamate + glutamine (rs-Glx) levels in their Heschl’s gyrus (HG), and related this to HG functional connectivity during a roving auditory oddball protocol. No rs-Glx effects were found within the frontotemporal prediction-error network. Larger rs-Glx signal was related to stronger connectivity between HG and bilateral inferior parietal lobule during unpredictable auditory stimulation. We also found effects of rs-Glx on the coherence of default mode network and frontoparietal network during unpredictable auditory stimulation. Our results demonstrate the importance of Glx in modulating long-range connections and wider networks in the brain during perceptual inference.

Frontoparietal Network Connectivity During an N-Back Task in Adults With Autism Spectrum Disorder.

BackgroundShort-term and working memory (STM and WM) deficits have been demonstrated in individuals with autism spectrum disorder (ASD) and may emerge through atypical functional activity and connectivity of the frontoparietal network, which exerts top-down control necessary for successful STM and WM processes. Little is known regarding the spectral properties of the frontoparietal network during STM or WM processes in ASD, although certain neural frequencies have been linked to specific neural mechanisms.MethodsWe analysed magnetoencephalographic data from 39 control adults (26 males; 27.15 ± 5.91 years old) and 40 adults with ASD (26 males; 27.17 ± 6.27 years old) during a 1-back condition (STM) of an n-back task, and from a subset of this sample during a 2-back condition (WM). We performed seed-based connectivity analyses using regions of the frontoparietal network. Interregional synchrony in theta, alpha, and beta bands was assessed with the phase difference derivative and compared between groups during periods of maintenance and recognition.ResultsDuring maintenance of newly presented vs. repeated stimuli, the two groups did not differ significantly in theta, alpha, or beta phase synchrony for either condition. Adults with ASD showed alpha-band synchrony in a network containing the right dorsolateral prefrontal cortex, bilateral inferior parietal lobules (IPL), and precuneus in both 1- and 2-back tasks, whereas controls demonstrated alpha-band synchrony in a sparser set of regions, including the left insula and IPL, in only the 1-back task. During recognition of repeated vs. newly presented stimuli, adults with ASD exhibited decreased theta-band connectivity compared to controls in a network with hubs in the right inferior frontal gyrus and left IPL in the 1-back condition. Whilst there were no group differences in connectivity in the 2-back condition, adults with ASD showed no frontoparietal network recruitment during recognition, whilst controls activated networks in the theta and beta bands.ConclusionsOur findings suggest that since adults with ASD performed well on the n-back task, their appropriate, but effortful recruitment of alpha-band mechanisms in the frontoparietal network to maintain items in STM and WM may compensate for atypical modulation of this network in the theta band to recognise previously presented items in STM.

Effects of emotional maltreatment on semantic network activity during cognitive reappraisal.

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.

Persistent Differences in Brain Structure in Developmental Dyscalculia: A Longitudinal Morphometry Study.

Developmental dyscalculia (DD) is a learning disability affecting the acquisition of numerical-arithmetical skills. Affected people show persistent deficits in number processing, which are associated with aberrant brain activation and structure. Reduced gray matter has been reported in DD for the parietal cortex including the intraparietal sulcus (IPS), but also the frontal and occipito-temporal cortex. Furthermore, dyscalculics show white matter differences for instance in the inferior (ILF) and superior longitudinal fasciculus (SLF). However, the longitudinal development of these structural differences is unknown. Therefore, our goal was to investigate the developmental trajectory of gray and white matter in children with and without DD. In this longitudinal study, neuropsychological measures and T1-weighted structural images were collected twice with an interval of 4 years from 13 children with DD (8.2–10.4 years) and 10 typically developing (TD) children (8.0–10.4 years). Voxel-wise estimation of gray and white matter volumes was assessed using voxel-based morphometry for longitudinal data. The present findings reveal for the first time that DD children show persistently reduced gray and white matter volumes over development. Reduced gray matter was found in the bilateral inferior parietal lobes including the IPS, supramarginal gyri, left precuneus, cuneus, right superior occipital gyrus, bilateral inferior and middle temporal gyri, and insula. White matter volumes were reduced in the bilateral ILF and SLF, inferior fronto-occipital fasciculus (IFOF), corticospinal tracts, and right anterior thalamic radiation (ATR). Behaviorally, children with DD performed significantly worse in various numerical tasks at baseline and follow-up, corroborating persistent deficits in number processing. The present results are in line with the literature showing that children with DD have reduced gray and white matter volumes in the numerical network. Our study further sheds light on the trajectory of brain development, revealing that these known structural differences in the long association fibers and the adjacent regions of the temporal- and frontoparietal cortex persist in dyscalculic children from childhood into adolescence. In conclusion, our results underscore that DD is a persistent learning disorder accompanied by deficits in number processing and reduced gray and white matter volumes in number related brain areas.

Acute Alcohol Intake Produces Widespread Decreases in Cortical Resting Signal Variability in Healthy Social Drinkers.

Acute alcohol intoxication has wide-ranging neurobehavioral effects on psychomotor, attentional, inhibitory, and memory-related cognitive processes. These effects are mirrored in disruption of neural metabolism, functional activation, and functional network coherence. Metrics of intraregional neural dynamics such as regional signal variability (RSV) and brain entropy (BEN) may capture unique aspects of neural functional capacity in healthy and clinical populations; however, alcohol's influence on these metrics is unclear. The present study aimed to elucidate the influence of acute alcohol intoxication on RSV and to clarify these effects with subsequent BEN analyses. 26 healthy adults between 25 and 45years of age (65.4% women) participated in 2 counterbalanced sessions. In one, participants consumed a beverage containing alcohol sufficient to produce a breath alcohol concentration of 0.08g/dl. In the other, they consumed a placebo beverage. Approximately 35minutes after beverage consumption, participants completed a 9-minute resting-state fMRI scan. Whole-brain, voxel-wise standard deviation was used to assess RSV, which was compared between sessions. Within clusters displaying alterations in RSV, sample entropy was calculated to assess BEN. Compared to the placebo, alcohol intake resulted in widespread reductions in RSV in the bilateral middle frontal, right inferior frontal, right superior frontal, bilateral posterior cingulate, bilateral middle temporal, right supramarginal gyri, and bilateral inferior parietal lobule. Within these clusters, significant reductions in BEN were found in the bilateral middle frontal and right superior frontal gyri. No effects were noted in subcortical or cerebellar areas. Findings indicate that alcohol intake produces diffuse reductions in RSV among structures associated with attentional processes. Within these structures, signal complexity was also reduced in a subset of frontal regions. Neurobehavioral effects of acute alcohol consumption may be partially driven by disruption of intraregional neural dynamics among regions involved in higher-order cognitive and attentional processes.

S149. CHANGES IN FRONTO-PARIETAL CONNECTIVITY IN SCHIZOPHRENIA: TMS AND FNIRS STUDY

BackgroundOne of the most prominent deficits in schizophrenia is impairment in executive function. This impairment is associated to aberrant function of the dorso-lateral prefrontal cortex (DLPFC)(Weinberger et al. 1986) and the fronto-parietal network (FPN) (Deserno et al. 2012). The FPN is involved in cognitive control (Seeley et al. 2007, Zanto & Gazzaley 2013). While correlations of activation of DLPFC and inferior parietal lobe (IPL) are well documented, fMRI based techniques cannot determine causal relationships of interactions between brain regions. We used Transcranial magnetic stimulation (TMS), which directly affects the stimulated brain region and connected brain areas (Valchev et al 2015) and therefore can be used to investigate causal interactions between brain regions. TMS stimulation to the DLPFC at 10 Hz may cause either putative increase or decrease of activation in the in the IPL, depending on whether connections are inhibitory or excitatory (Curtin et al 2019). We hypothesised that patients with schizophrenia would have slower reaction in IPL as a consequence of DLPFC stimulation.MethodsThirteen patients and fourteen healthy controls (HC) underwent transcranial magnetic stimulation (TMS) to the right DLPFC. TMS consisted of 20 trains of impulses at 10 Hz for 3 seconds, and 60 seconds waiting time. Simultaneously, we measured brain activation IPL using functional near infrared spectroscopy (fNIRS). Diagnostic category was confirmed using MINI plus interview. The severity of symptoms was assessed using the positive and negative syndrome scale (PANSS). We estimated levels of Oxygenised haemoglobin (HbO) using NIRSLab software. GLM was applied using both hemodynamic response function (HRF) and it’s derivative. T-test was used, with FDR correction, to compare time segments of HbO following TMS stimulation.ResultsThere was no difference in age and gender between the groups. The two groups differed in education (t(2,25)= 2,584, p=0.016). GLM revealed decreased levels of HbO in HC in bilateral IPL following the TMS to the DLPFC (p_bonferroni=0.05). However, when patients were compared to HC higher levels of HbO were observed (p=0.05). However, no difference in derivative of HRF was observed. In addition, there was a significant difference in time courses between patients and HC following TMS stimulation. Namely, while there was an immediate decrease in parietal HbO levels in HC, in SZ first an increase, followed by a decrease was observed. This was significant (at a threshold level of pFDR=0.05) for several time segments and channels in both right and left IPL.DiscussionWe observed differences in activation of bilateral IPL as a consequence of DLPFC stimulation in patients with schizophrenia. Namely, there was an initial increase in HbO levels, as opposite to HC who had an immediate decrease in HbO level. This indicates opposite function of information processing from the frontal to parietal lobe in schizophrenia patients. This is in line with the idea of impaired fronto-parietal inhibition in schizophrenia which has been proposed to underlie impairments in schizophrenia such as lack of cognitive control.

Neural correlates of conditioned pain responses in fibromyalgia subjects indicate preferential formation of new pain associations rather than extinction of irrelevant ones.

Behavioral studies have demonstrated aberrant safety processing in fibromyalgia subjects (FMSs) and suggested that patients accumulate new potential pain-related threats more effectively than extinguishing no longer relevant ones. The aim of the current study was to investigate the neural correlates of conditioned pain responses and their relationship with emotional distress in FMS (n = 67) and healthy controls (HCs, n = 34). Using functional magnetic resonance imaging, we traced conditioned pain responses to an identical moderately painful pressure (P30) depending on whether it was following a green (P30green) or a red (P30red) cue. The cues were previously associated with individually calibrated painful pressure stimuli of low and high intensity, corresponding to visual analogue scale 10 and 50 mm, respectively. Fibromyalgia subjects displayed increased P30green ratings over time, while P30red ratings remained elevated. Healthy controls adapted all pain ratings to resemble moderate pain. Fibromyalgia subjects exhibited increased activation for [P30green>P30red] in M1/anterior insula, whereas HC showed increased S2/mid-insula response to [P30red>P30green]. High pain catastrophizing scale (PCS) ratings in fibromyalgia (FM) covaried with heightened brain activation for [P30green] × PCS in left dorsolateral prefrontal cortex and medial prefrontal cortex/orbitofrontal cortex; and [P30green>P30red] × PCS in dorsal anterior cingulate cortex/mid-cingulate cortex; superior temporal pole, extending to anterior insula; bilateral thalamus; and posterior insula. Psychophysiological interaction analysis for FM [P30green>P30red] × PCS revealed a dissociation in functional connectivity between thalamus and bilateral inferior parietal lobe. In alignment with behavioral data, FMS displayed a cerebral response suggesting preferential formation of new pain-related associations while simultaneously maintaining no longer relevant ones. The opposite was observed in HC. Increased responses to pain-related threats in FM may contribute to dysfunctional pain-protective behaviors and disability.

The Default Mode Network In Patient with Temporal Lobe Epilepsy (TLE): A Resting State fMRI Study

The default mode network (DMN) is involved in conscious, resting state cognition and is thought to be affected in TLE where seizures cause impairment of consciousness. The study aimed to evaluate the brain activation of the DMN regions in both temporal lobe epilepsy (TLE) patients and healthy subjects by using resting-state functional Magnetic Resonance Imaging (rsfMRI) technique. A same number of fourteen participants with age and gender matched for the healthy subjects and TLE patients were selected with the average age is 36.9 and 37.0 years old, respectively. The rsfMRI imaging protocol was executed using a 3-T Phillips Achieva MRI scanner at the Radiology Department, Hospital Universiti Sains Malaysia (HUSM). For healthy subjects, the brain activation cluster in bilateral superior parietal lobes (SPL),precuneus (PRE), supramarginal gyrus (SMG) and inferior parietal lobes (IPL) were found higher than TLE patients. While for TLE patients displays higher activation clusters in bilateral MFG, STG, and ANG. The result from random effects (RFX) on two-sample t-tests thresholded at p = 0.001 revealed that the TLE patients display significantly higher activations on the bilateral superior frontal gyrus (SFG), left SMG, left middle frontal gyrus (MFG) and right IPL. However for the core-region of DMN such as bilateral precuneus, left MFG, bilateral STG and bilateral IPL were significantly activated but the number of voxels survives are substantially smaller than other regions such as bilateral SFG. The findings suggested that TLE patients may suffer from an impairment in some DMN region, which may cause certain neuropsychological and cognitive degradation.&#x0D; &#x0D; &#x0D; &#x0D; Keywords: resting-state fMRI, temporal lobe epilepsy, brain activation, two-sample t-tests

Prefrontal Cortical Reactivity and Connectivity Markers Distinguish Youth Depression from Healthy Youth

Up to 50% of youth with depression do not respond to conventional first-line treatments. However, little research has been conducted on the pathophysiology of youth depression, hindering the identification of more effective treatments. Our goal was to identify neurophysiological markers that differentiate youth with depression from healthy youth and could serve as targets of novel treatments. We hypothesized that youth with depression would exhibit network-specific cortical reactivity and connectivity abnormalities compared with healthy youth. Transcranial magnetic stimulation combined with electroencephalography and magnetic resonance imaging was employed in combination with clinical and behavioral assessments to study cortical reactivity and connectivity in bilateral dorsolateral prefrontal cortex (DLPFC), motor cortex, and inferior parietal lobule, sites linked to the frontoparietal network, sensorimotor network, and default mode network, respectively. In youth depression, greater cortical reactivity was observed specific to the left and right DLPFC stimulation only, which correlated with anhedonia scores. Additionally, the connectivity of the right DLPFC was significantly higher in youth depression. Source reconstruction attributed the observed connectivity dysregulation to regions belonging to the default mode network. The neurophysiological signatures identified in this study have high potential to inform the development of more effective and targeted interventions for the youth depression population.

Dysbalanced Resting-State Functional Connectivity Within the Praxis Network Is Linked to Gesture Deficits in Schizophrenia.

Patients with schizophrenia frequently present deficits in gesture production and interpretation, greatly affecting their communication skills. As these gesture deficits can be found early in the course of illness and as they can predict later outcomes, exploring their neural basis may lead to a better understanding of schizophrenia. While gesturing has been reported to rely on a left lateralized network of brain regions, termed praxis network, in healthy subjects and lesioned patients, studies in patients with schizophrenia are sparse. It is currently unclear whether within-network connectivity at rest is linked to gesture deficit. Here, we compared the functional connectivity between regions of the praxis network at rest between 46 patients and 44 healthy controls. All participants completed a validated test of hand gesture performance before resting-state functional magnetic resonance imaging (fMRI) was acquired. Patients performed gestures poorer than controls in all categories and domains. In patients, we also found significantly higher resting-state functional connectivity between left precentral gyrus and bilateral superior and inferior parietal lobule. Likewise, patients had higher connectivity from right precentral gyrus to left inferior and bilateral superior parietal lobule (SPL). In contrast, they exhibited lower connectivity between bilateral superior temporal gyrus (STG). Connectivity between right precentral gyrus and left SPL, as well as connectivity between bilateral STG, correlated with gesture performance in healthy controls. We failed to detect similar correlations in patients. We suggest that altered resting-state functional connectivity within the praxis network perturbs correct gesture planning in patients, reflecting the gesture deficit often seen in schizophrenia.

Differences between children and adults in functional connectivity between the inferior frontal gyrus and extrastriate body area for gestural interaction

ABSTRACT Gestural interaction, where a person initiates interaction (initiator) and another person responds to it (follower), changes during development. The neural network comprising the inferior frontal gyrus (IFG), inferior parietal lobule (IPL), and the lateral occipito-temporal cortex (LOTC) is relevant to gestural interaction. The LOTC includes the extrastriate body area (EBA). Activation of these brain regions depends on the initiating/following role in adults. We conducted functional magnetic resonance imaging study on 18 children and 18 adults, to elucidate developmental changes of the neural mechanism underlying gestural interaction. We manipulated the initiating/following role (initiating/following) and congruency (congruent/incongruent) of executed and observed actions. After analyzing regional brain activity, we assessed psycho-physiological interaction to examine functional connectivity. Activation in the IFG and connectivity between the IFG and EBA in the Initiating rather than Following condition, which might be associated with evaluating social relevance, was stronger in adults than in children. The increase of the incongruency effect in the following condition (relative to the initiating condition) in the bilateral IPL was significantly attenuated in children compared with adults. These results suggest that the fronto-parieto-temporal network, involved in gestural interactions, undergoes developmental changes.

Effects of COMT rs4680 and BDNF rs6265 polymorphisms on brain degree centrality in Han Chinese adults who lost their only child

Losing one’s only child is a major traumatic life event that may lead to posttraumatic stress disorder (PTSD); however, not all parents who experience this trauma develop PTSD. Genetic variants are associated with the risk of developing PTSD. Catechol-O-methyltransferase (COMT) rs4680 and brain-derived neurotrophic factor (BDNF) rs6265 are two most well-described single-nucleotide polymorphisms that relate to stress response; however, the neural mechanism underlying their effects on adults who lost an only child remains poorly understood. Two hundred and ten Han Chinese adults who had lost their only child (55 with PTSD and 155 without PTSD) were included in this imaging genetics study. Participants were divided into subgroups according to their COMT rs4680 and BDNF rs6265 genotypes. Degree Centrality (DC)—a resting-state fMRI index reflecting the brain network communication—was compared with a three-way (PTSD diagnosis, COMT, and BDNF polymorphisms) analysis of covariance. Diagnosis state had a significant effect on DC in bilateral inferior parietal lobules and right middle frontal gyrus (MFG), where PTSD adults showed weaker DC. BDNF × diagnosis interaction effect was found in the right MFG and hippocampus, and these two regions were reversely modulated. Also, there was a significant COMT × BDNF interaction effect in left cuneus, middle temporal gyrus, right inferior occipital gyrus, and bilateral putamen, independent of PTSD diagnosis. These findings suggest that the modulatory effect of BDNF polymorphism on the MFG and hippocampus may contribute to PTSD development in bereaved adults. Interactions of COMT × BDNF polymorphisms modulate some cortices and basal ganglia, irrespective of PTSD development.

Elements of creative thought: Investigating the cognitive and neural correlates of association and bi-association processes

Creative thinking relies on the ability to make remote associations and fruitfully combine unrelated concepts. Hence, original associations and bi-associations (i.e., associations to one and two concepts, respectively) are considered elementary cognitive processes of creative cognition. In this work, we investigated the cognitive and brain mechanisms underlying these association processes with tasks that asked for original associations to either one or two adjective stimuli. Study 1 showed that the generation of more original associations and bi-associations was related to several indicators of creativity, corroborating the validity of these association performances as basic processes underlying creative cognition. Study 2 assessed brain activity during performance of these association tasks by means of fMRI. The generation of original versus common associations was related to higher activation in bilateral lingual gyri suggesting that cued search for remote representatives of given properties are supported by visually-mediated search strategies. Parametric analyses further showed that the generation of more original associations involved activation of the left inferior frontal cortex and the left ventromedial prefrontal cortex, which are consistently implicated in constrained retrieval and evaluation processes, and relevant for making distant semantic connections. Finally, the generation of original bi-associations involved higher activation in bilateral hippocampus and inferior parietal lobe, indicating that conceptual combination recruits episodic simulation processes. Together, these findings suggest that the generation of verbally cued, original associations relies not only on verbal semantic memory but involves mental imagery and episodic simulation, offering new insights in the nuanced interplay of memory systems in creative thought.

Patterns of brain regional functional coherence in cognitive impaired ALS

Background: The aim of the study is to reveal the brain regional functional coherence alterations in the early-stage amyotrophic lateral sclerosis (ALS) patients with cognitive impairments.Methods: Resting state functional MRI (fMRI) was performed to characterize the amplitude of regional homogeneity (ReHo). Twenty-one ALS patients with cognitive impairments (ALSci), 21 ALS patients without cognitive impairments (ALSnci) and 21 healthy controls (HCs) were enrolled.Result: Compared with HCs, the ALSci subgroup showed increased ReHo in bilateral inferior parietal lobules (IPLs), precuneus and inferior cerebellar areas, and the ALSnci subgroup had increased ReHo in the left IPL and left inferior cerebellar area. The ALSci subgroup also had increased ReHo in the right IPL and right inferior cerebellar area relative to the ALSnci subgroup. Meantime, compared with HCs, both ALS subgroups showed decreased ReHo in bilateral sensorimotor cortices. The ReHo values in the right cerebellar area were negatively correlated with the Chinese version of Addenbrooke Cognitive Examination–revised (ACE-R) total scores in all ALS patients. In addition, the grey matter (GM) volume revealed no significant difference among three groups, which indicated that the altered ReHo was not caused by the anatomic change.Conclusion: The altered regional functional coherence might indicate the underlying deficits of ALS with and without cognitive impairments. Our findings support that ALS is a multisystem disease and provide the evidence that alterations of ReHo in the right inferior cerebellar area might be a special marker of ALS with cognitive impairment. Our results are preliminary and further investigations are needed.

The Stroop effect: An activation likelihood estimation meta-analysis in healthy young adults

Age plays a significant role in executive control processes in the Stroop task. This study aims to draw together the Stroop tasks to determine the role of the frontal cortex in cognitive control among healthy young adults using activation likelihood estimation. Forty-six studies were selected according to the fMRI neuroimaging tools, Stroop experimental tasks, young participants’ age. The results showed that the contrast of incongruent conditions and congruent conditions revealed 7 significant clusters, including the right cingulate cortex, left dorsolateral prefrontal cortex, bilateral inferior frontal gyrus, right superior frontal gyrus and temporal cortex. In addition, the contrast comparing incongruent conditions with neutral conditions activated a network including the right inferior frontal gyrus, left dorsolateral prefrontal cortex, bilateral medial frontal cortex, left insular cortex and bilateral inferior parietal lobule and precuneus. In this study, we found that the brain areas for executive performance had a higher concordance in the frontal cortex among healthy young adults than temporal-parietal network.