scholarly journals Inside Information: Systematic within-node connectivity changes observed across tasks or groups

2021 ◽  
Author(s):  
Wenjing Luo ◽  
Robert T Constable
Keyword(s):  
Brain Function ◽  
Inside Information ◽  
Substantial Fraction ◽  
Connectivity Information ◽  
Or Groups ◽  
Node Connectivity ◽  
Clinical Potential

Mapping the human connectome and understanding its relationship to brain function holds tremendous clinical potential. The connectome has two fundamental components: the nodes and the connections between them. While much attention has been given to deriving atlases and measuring the connections between nodes, there have been no studies examining the networks within nodes. Here we demonstrate that each node contains significant connectivity information, that varies systematically across task-induced states and subjects, such that measures based on these variations can be used to classify tasks and identify subjects. The results are not specific for any particular atlas but hold across different atlas resolutions. To date, studies examining changes in connectivity have focused on edge changes and assumed there is no useful information within nodes. Our findings illustrate that for typical atlases, within-node changes can be significant and may account for a substantial fraction of the variance currently attributed to edge changes.

The pattern of monosynaptic I a-connections to hindlimb motor nuclei in the baboon: a comparison with the cat

1984 ◽  
Vol 221 (1224) ◽  
pp. 261-289 ◽  
Keyword(s):  
Intracellular Recording ◽  
Brain Function ◽  
Tonic Inhibition ◽  
Resting Potential ◽  
Inhibitory Pathway ◽  
Plantaris Tendon ◽  
Hindlimb Muscles ◽  
Or Groups ◽  
Motor Nuclei ◽  
Knee Flexors

The pattern of la-connections to motor nuclei of 17 hindlimb muscles (or groups of muscles) has been investigated in baboons by intracellular recording of Ia-e.ps.p.s evoked in motoneurons from different muscle nerves. The amplitudes are normalized to 70 mV resting potential and compared with similarly normalized Ia-e.ps.p.s in cats. As in the cat, la-excitation is drawn from a restricted number of muscles and the homonymous effect is usually dominating. Heteronymous connections to many motor nuclei are different in the two species. For example, hip extensors are generally more la-isolated from each other in baboons than in cats, and also knee flexors have fewer Iainterconnections than in cats. A unidirectional Ia-synergism between some hip extensors and knee flexors in cats has changed to a bidirectional one in baboons, with a tendency to lateralization of the connections. Among ankle extensors, soleus has smaller heteronymous I a-connections from its synergic ankle extensors than in cats. In baboons, plantaris is heteronymously I a-excited from gastrocnemius-soleus but not from the intrinsic plantar muscles; whereas in cats there exists a considerable la-projection from the intrinsic plantar muscles but not from gastrocnemius-soleus. There is a corresponding difference in the insertion of the plantaris tendon, which shows that this muscle acts as toe extensor in cats but as ankle extensor in baboons. For most of the motor nuclei, the homonymous as well as the total aggregate of Ia-e.ps.p.s is smaller in the baboon than in the cat; but the amplitude range between different motor nuclei is larger in the baboon. Reciprocal Ia-i.ps.p.s are evoked only after spinal transection or when brain function is depressed. It is postulated that baboons, contrary to cats, have descending tonic inhibition of transmission in the reciprocal la-inhibitory pathway. The phylogenetic flexibility of I a-connections is discussed and contrasted with their ontogenetic stability.

A challenge for predictive coding: Representational or experiential diversity?

2020 ◽  
Vol 43 ◽  
Author(s):  
Martina G. Vilas ◽  
Lucia Melloni
Keyword(s):  
Brain Function ◽  
Predictive Coding ◽  
Predictive Processing ◽  
Process Theory

Abstract To become a unifying theory of brain function, predictive processing (PP) must accommodate its rich representational diversity. Gilead et al. claim such diversity requires a multi-process theory, and thus is out of reach for PP, which postulates a universal canonical computation. We contend this argument and instead propose that PP fails to account for the experiential level of representations.

Toward a neuroscope: An application of high-performance computing for real-time evaluation of brain function using MRI

1994 ◽  
Vol 52 ◽  
pp. 922-923
Author(s):  
C. S. Potter ◽  
C. D. Gregory ◽  
H. D. Morris ◽  
Z.-P. Liang ◽  
P. C. Lauterbur
Keyword(s):  
Human Brain ◽  
Brain Function ◽  
High Performance ◽  
Complex Signal ◽  
Time Step ◽  
Brain Organization ◽  
Cognitive Studies ◽  
Positron Emission ◽  
Imaging And Spectroscopy ◽  
3D Anatomy

Over the past few years, several laboratories have demonstrated that changes in local neuronal activity associated with human brain function can be detected by magnetic resonance imaging and spectroscopy. Using these methods, the effects of sensory and motor stimulation have been observed and cognitive studies have begun. These new methods promise to make possible even more rapid and extensive studies of brain organization and responses than those now in use, such as positron emission tomography.Human brain studies are enormously complex. Signal changes on the order of a few percent must be detected against the background of the complex 3D anatomy of the human brain. Today, most functional MR experiments are performed using several 2D slice images acquired at each time step or stimulation condition of the experimental protocol. It is generally believed that true 3D experiments must be performed for many cognitive experiments. To provide adequate resolution, this requires that data must be acquired faster and/or more efficiently to support 3D functional analysis.

Characteristics of the Frequency-Following Response to Speech in Neonates and Potential Applicability in Clinical Practice: A Systematic Review

2020 ◽  
Vol 63 (5) ◽  
pp. 1618-1635
Author(s):  
Céline Richard ◽  
Mary Lauren Neel ◽  
Arnaud Jeanvoine ◽  
Sharon Mc Connell ◽  
Alison Gehred ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cochrane Library ◽  
Neurodevelopmental Outcomes ◽  
Frequency Following Response ◽  
Ovid Medline ◽  
Published Evidence ◽  
Mesh Terms ◽  
Potential Applicability ◽  
Clinical Potential

Purpose We sought to critically analyze and evaluate published evidence regarding feasibility and clinical potential for predicting neurodevelopmental outcomes of the frequency-following responses (FFRs) to speech recordings in neonates (birth to 28 days). Method A systematic search of MeSH terms in the Cumulative Index to Nursing and Allied HealthLiterature, Embase, Google Scholar, Ovid Medline (R) and E-Pub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily, Web of Science, SCOPUS, COCHRANE Library, and ClinicalTrials.gov was performed. Manual review of all items identified in the search was performed by two independent reviewers. Articles were evaluated based on the level of methodological quality and evidence according to the RTI item bank. Results Seven articles met inclusion criteria. None of the included studies reported neurodevelopmental outcomes past 3 months of age. Quality of the evidence ranged from moderate to high. Protocol variations were frequent. Conclusions Based on this systematic review, the FFR to speech can capture both temporal and spectral acoustic features in neonates. It can accurately be recorded in a fast and easy manner at the infant's bedside. However, at this time, further studies are needed to identify and validate which FFR features could be incorporated as an addition to standard evaluation of infant sound processing evaluation in subcortico-cortical networks. This review identifies the need for further research focused on identifying specific features of the neonatal FFRs, those with predictive value for early childhood outcomes to help guide targeted early speech and hearing interventions.

Monitor Brain Function Selectively

2005 ◽  
Vol 38 (24) ◽  
pp. 18
Author(s):  
MARY ELLEN SCHNEIDER
Keyword(s):  
Brain Function

The Psychophysiology of Anxiety and Mood Disorders

2017 ◽  
Vol 225 (3) ◽  
pp. 175-188 ◽  
Author(s):  
Peter J. Lang ◽  
Lisa M. McTeague ◽  
Margaret M. Bradley
Keyword(s):  
Mental Health ◽  
Heart Rate ◽  
Brain Function ◽  
Physiological Reactivity ◽  
Research Domain Criteria ◽  
Diagnostic Systems ◽  
Psychophysiological Reactivity ◽  
Diagnostic Categories ◽  
New Research ◽  
Research Domain

Abstract. Several decades of research are reviewed, assessing patterns of psychophysiological reactivity in anxiety patients responding to a fear/threat imagery challenge. Findings show substantive differences in these measures within principal diagnostic categories, questioning the reliability and categorical specificity of current diagnostic systems. Following a new research framework (US National Institute of Mental Health [NIMH], Research Domain Criteria [RDoC]; Cuthbert & Insel, 2013 ), dimensional patterns of physiological reactivity are explored in a large sample of anxiety and mood disorder patients. Patients’ responses (e.g., startle reflex, heart rate) during fear/threat imagery varied significantly with higher questionnaire measured “negative affect,” stress history, and overall life dysfunction – bio-marking disorder groups, independent of Diagnostic and Statistical Manuals (DSM). The review concludes with a description of new research, currently underway, exploring brain function indices (structure activation, circuit connectivity) as potential biological classifiers (collectively with the reflex physiology) of anxiety and mood pathology.

Review of Nutrients and Brain Function.

1989 ◽  
Vol 34 (8) ◽  
pp. 801-801
Author(s):  
No authorship indicated
Keyword(s):  
Brain Function
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