Zang YF papers

Default mode network mediates low-frequency fluctuations in brain activity and behavior during sustained attention

Fri, 07/29/2022 - 18:00

Hum Brain Mapp. 2022 Jul 29. doi: 10.1002/hbm.26024. Online ahead of print.


The low-frequency (<0.1 Hz) fluctuation in sustained attention attracts enormous interest in cognitive neuroscience and clinical research since it always leads to cognitive and behavioral lapses. What is the source of the spontaneous fluctuation in sustained attention in neural activity, and how does the neural fluctuation relate to behavioral fluctuation? Here, we address these questions by collecting and analyzing two independent fMRI and behavior datasets. We show that the neural (fMRI) fluctuation in a key brain network, the default-mode network (DMN), mediate behavioral (reaction time) fluctuation during sustained attention. DMN shows the increased amplitude of fluctuation, which correlates with the behavioral fluctuation in a similar frequency range (0.01-0.1 Hz) but not in the lower (<0.01 Hz) or higher (>0.1 Hz) frequency range. This was observed during both auditory and visual sustained attention and was replicable across independent datasets. These results provide a novel insight into the neural source of attention-fluctuation and extend the former concept that DMN was deactivated in cognitive tasks. More generally, our findings highlight the temporal dynamic of the brain-behavior relationship.

PMID:35903957 | DOI:10.1002/hbm.26024

Aberrant visual-related networks in familial cortical myoclonic tremor with epilepsy

Sat, 07/23/2022 - 18:00

Parkinsonism Relat Disord. 2022 Jul 19;101:105-110. doi: 10.1016/j.parkreldis.2022.07.001. Online ahead of print.


INTRODUCTION: In familial cortical myoclonic tremor with epilepsy, photic stimulation can trigger visual symptoms and induce a photoparoxysmal response, or photosensitivity, on electroencephalography. However, the mechanism is poorly understood. In this study, we aimed to explore the neuroimaging changes related to visual symptoms and photosensitivity in genetically confirmed familial cortical myoclonic tremor with epilepsy type 1.

METHODS: Resting-state functional magnetic resonance imaging and electroencephalography data were collected from 31 patients carrying the heterozygous pathogenic intronic pentanucleotide (TTTCA)n insertion in the sterile alpha motif domain-containing 12 gene and from 52 age- and sex-matched healthy controls.

RESULTS: (1) Both regional homogeneity and degree centrality values in the bilateral calcarine sulcus were significantly increased in patients compared with healthy controls. (2) When the calcarine sulcus area with increased regional homogeneity was taken as a seed, increased functional connectivity values were observed in the right precentral gyrus, while decreased functional connectivity values were observed in the right superior frontal gyrus and right inferior parietal lobule. (3) Independent component analysis showed increased connectivity in the left calcarine sulcus inside the medial visual network. (4) Correlation analysis revealed a significant positive correlation between regional homogeneity values and frequency of seizure, and photoparoxysmal response grades were positively correlated with the severity of cortical tremor and duration of epilepsy.

CONCLUSION: These findings provide strong evidence for the interpretation of visual symptoms and photosensitivity in familial cortical myoclonic tremor with epilepsy. We speculate that functional changes in the primary visual cortex may be an imaging biomarker for the disease.

PMID:35870251 | DOI:10.1016/j.parkreldis.2022.07.001

Lifespan associations of resting-state brain functional networks with ADHD symptoms

Thu, 07/14/2022 - 18:00

iScience. 2022 Jun 26;25(7):104673. doi: 10.1016/j.isci.2022.104673. eCollection 2022 Jul 15.


Attention-deficit/hyperactivity disorder (ADHD) is increasingly being diagnosed in both children and adults, but the neural mechanisms that underlie its distinct symptoms and whether children and adults share the same mechanism remain poorly understood. Here, we used a nested-spectral partition approach to study resting-state brain networks of ADHD patients (n = 97) and healthy controls (HCs, n = 97) across the lifespan (7-50 years). Compared to the linear lifespan associations of brain segregation and integration with age in HCs, ADHD patients have a quadratic association in the whole-brain and in most functional systems, whereas the limbic system dominantly affected by ADHD has a linear association. Furthermore, the limbic system better predicts hyperactivity, and the salient attention system better predicts inattention. These predictions are shared in children and adults with ADHD. Our findings reveal a lifespan association of brain networks with ADHD and provide potential shared neural bases of distinct ADHD symptoms in children and adults.

PMID:35832890 | PMC:PMC9272385 | DOI:10.1016/j.isci.2022.104673