Prevent breaking bad: A proof of concept study of rebalancing the brain's rumination circuit with real‐time fMRI functional connectivity neurofeedback

Rumination, repetitively thinking about the causes, consequences, and one''s negative affect, has been considered as an important factor of depression. The intrusion of ruminative thoughts is not easily controlled, and it may be useful to visualize one''s neural activity related to rumination and to use that information to facilitate one''s self‐control. Real‐time fMRI neurofeedback (rtfMRI‐nf) enables one to see and regulate the fMRI signal from their own brain. This proof‐of concept study utilized connectivity‐based rtfMRI‐nf (cnf) to normalize brain functional connectivity (FC) associated with rumination. Healthy participants were instructed to brake or decrease FC between the precuneus and the right temporoparietal junction (rTPJ), associated with high levels of rumination, while engaging in a self‐referential task. The cnf group (n = 14) showed a linear decrease in the precuneus‐rTPJ FC across neurofeedback training (trend [112] = −0.180, 95% confidence interval [CI] −0.330 to −0.031, while the sham group (n = 14) showed a linear increase in the target FC (trend [112] = 0.151, 95% CI 0.017 to 0.299). Although the cnf group showed a greater reduction in state‐rumination compared to the sham group after neurofeedback training (p < .05), decoupled precuneus‐rTPJ FC did not predict attenuated state‐rumination. We did not find any significant aversive effects of rtfMRI‐nf in all study participants. These results suggest that cnf has the capacity to influence FC among precuneus and rTPJ of a ruminative brain circuit. This approach can be applied to mood and anxiety patients to determine the clinical benefits of reduction in maladaptive rumination.     

持续性姿势-感知性头晕患者脑功能网络度中心度研究

目的:应用基于体素的度中心度(DC)方法,探讨持续性姿势-感知性头晕(PPPD)患者脑功能网络的改变。方法:纳入PPPD患者12例及健康受试者12例,均进行静息态功能核磁成像(f MRI),采用基于体素的DC方法分析f MRI数据,比较PPPD患者与健康受试者的差异。进一步进行相关分析,探讨DC改变与PPPD患者临床特征的相关性。结果:与健康受试者相比,PPPD患者右侧楔叶、楔前叶(X=12,Y=-84,Z=21,k=126,P=0.011, FWE校正)DC值显著降低。DC值与DHI(r=-0.677,P=0.016)、DHI-F(r=-0.581,P=0.048)、DHI-E(r=-0.690,P=0.013)均呈负相关。结论:PPPD患者楔叶、楔前叶网络节点属性减弱,可能与患者的持续性头晕不稳及复杂视觉刺激导致症状加重有关。     

Network connectivity predicts language processing in healthy adults

Brain imaging has been used to predict language skills during development and neuropathology but its accuracy in predicting language performance in healthy adults has been poorly investigated. To address this shortcoming, we studied the ability to predict reading accuracy and single‐word comprehension scores from rest‐ and task‐based functional magnetic resonance imaging (fMRI) datasets of 424 healthy adults. Using connectome‐based predictive modeling, we identified functional brain networks with >400 edges that predicted language scores and were reproducible in independent data sets. To simplify these complex models we identified the overlapping edges derived from the three task‐fMRI sessions (language, working memory, and motor tasks), and found 12 edges for reading recognition and 11 edges for vocabulary comprehension that accounted for 20% of the variance of these scores, both in the training sample and in the independent sample. The overlapping edges predominantly emanated from language areas within the frontoparietal and default‐mode networks, with a strong precuneus prominence. These findings identify a small subset of edges that accounted for a significant fraction of the variance in language performance that might serve as neuromarkers for neuromodulation interventions to improve language performance or for presurgical planning to minimize language impairments.     

Look at those two!: The precuneus role in unattended third‐person perspective of social interactions

Human beings often observe other people's social interactions without being a part of them. Whereas the implications of some brain regions (e.g. amygdala) have been extensively examined, the implication of the precuneus remains yet to be determined. Here we examined the implication of the precuneus in third‐person perspective of social interaction using functional magnetic resonance imaging (fMRI). Participants performed a socially irrelevant task while watching the biological motion of two agents acting in either typical (congruent to social conventions) or atypical (incongruent to social conventions) ways. When compared to typical displays, the atypical displays elicited greater activation in the central and posterior bilateral precuneus, and in frontoparietal and occipital regions. Whereas the right precuneus responded with greater activation also to upside down than upright displays, the left precuneus did not. Correlations and effective connectivity analysis added consistent evidence of an interhemispheric asymmetry between the right and left precuneus. These findings suggest that the precuneus reacts to violations of social expectations, and plays a crucial role in third‐person perspective of others' interaction even when the social context is unattended. Hum Brain Mapp 35:5190–5203, 2014. © 2014 Wiley Periodicals, Inc .     

Prioritizing new over old: an fMRI study of the preview search task

In visual search, observers can successfully ignore temporally separated distractors that are presented as a preview before onset of the search display. Previous behavioral studies have demonstrated the involvement of top-down selection mechanisms in preview search, biasing attention against the old set in favor of the more relevant new set. Using functional magnetic resonance imaging, we replicate and extend findings showing the involvement of superior and inferior parietal areas in the preview task when compared to both a relatively easy single-set search task and a more effortful full-set search task. In contrast, the effortful full-set search showed activation in the dorsolateral prefrontal cortex when compared to the single-set search, suggesting that this area is involved in rejecting additional distractors that could not be separated in time.     

Magnetic Resonance Imaging Volume of the Angular Gyri Predicts Financial Skill Deficits in People with Amnestic Mild Cognitive Impairment

OBJECTIVES: To better understand how brain atrophy in amnestic mild cognitive impairment (MCI) as measured using magnetic resonance imaging (MRI) volumetrics could affect instrumental activities of daily living (IADLs) such as financial abilities. DESIGN: Controlled, matched‐sample, cross‐sectional analysis regressing MRI volumetrics with financial performance measures. SETTING: University medical and research center. PARTICIPANTS: Thirty‐eight people with MCI and 28 older adult controls. MEASUREMENTS: MRI volumetric measurement of the hippocampi, angular gyri, precunei, and medial frontal lobes. Participants also completed neuropsychological tests and the Financial Capacity Instrument (FCI). RESULTS: Correlations were performed between FCI scores and MRI volumes in the group with MCI. People with MCI performed significantly below controls on the FCI and had significantly smaller hippocampi. Among people with MCI, performance on the FCI was moderately correlated with angular gyri and precunei volumes. Regression models demonstrated that angular gyrus volumes were predictive of FCI scores. Tests of mediation showed that measures of arithmetic and possibly attention partially mediated the relationship between angular gyrus volume and FCI score. CONCLUSION: Impaired financial abilities in amnestic MCI correspond with volume of the angular gyri as mediated by arithmetic knowledge. The findings suggest that early neuropathology within the lateral parietal region in MCI leads to a breakdown of cognitive abilities that affect everyday financial skills. The findings have implications for diagnosis and clinical care of people with MCI and AD.     

Insight into the precuneus: a novel seizure semiology in a child with epilepsy arising from the right posterior precuneus

To date, there is limited understanding of the role of the precuneus. fMRI studies have suggested its involvement in a wide spectrum of highly integrated tasks, including spatially‐guided behaviour, visuo‐spatial imagery, and consciousness. We present a patient with intractable parietal lobe epilepsy arising from a lesion localized to the right precuneus. Two seizure types with distinct semiologies were captured on video‐EEG monitoring. The first type consisted of an urge described as a “feeling of wanting to move”. On video analysis, the patient is seen to turn his head and body to his left. He remains conscious, he is able to answer questions and when asked, he can look to his right. This seizure was associated with an ictal pattern localized to the right parieto‐occipital region. The second seizure type consisted of reading‐induced visual distortion with macropsia and micropsia. Interictally, intermittent rhythmic slowing and spikes were seen and localized to the parietal midline and the right parieto‐occipital regions. Our patient's seizures are positive phenomena of the right precuneus and its related processing network. They represent unique seizure semiologies that offer further insight into the role of the precuneus in spatial awareness, visuo‐spatial processing and consciousness.