scholarly journals Delta and gamma oscillations in operculo-insular cortex underlie innocuous cold thermosensation

2017 ◽  
Vol 117 (5) ◽  
pp. 1959-1968 ◽  
Author(s):  
Francesca Fardo ◽  
Mikkel C. Vinding ◽  
Micah Allen ◽  
Troels Staehelin Jensen ◽  
Nanna Brix Finnerup
Keyword(s):  
Evoked Potentials ◽  
Time Course ◽  
Pain Perception ◽  
Functional Integration ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Neural Pathways ◽  
Healthy Human ◽  
Central Processing ◽  
Evoked Fields

Cold-sensitive and nociceptive neural pathways interact to shape the quality and intensity of thermal and pain perception. Yet the central processing of cold thermosensation in the human brain has not been extensively studied. Here, we used magnetoencephalography and EEG in healthy volunteers to investigate the time course (evoked fields and potentials) and oscillatory activity associated with the perception of cold temperature changes. Nonnoxious cold stimuli consisting of Δ3°C and Δ5°C decrements from an adapting temperature of 35°C were delivered on the dorsum of the left hand via a contact thermode. Cold-evoked fields peaked at around 240 and 500 ms, at peak latencies similar to the N1 and P2 cold-evoked potentials. Importantly, cold-related changes in oscillatory power indicated that innocuous thermosensation is mediated by oscillatory activity in the range of delta (1–4 Hz) and gamma (55–90 Hz) rhythms, originating in operculo-insular cortical regions. We suggest that delta rhythms coordinate functional integration between operculo-insular and frontoparietal regions, while gamma rhythms reflect local sensory processing in operculo-insular areas. NEW & NOTEWORTHY Using magnetoencephalography, we identified spatiotemporal features of central cold processing, with respect to the time course, oscillatory profile, and neural generators of cold-evoked responses in healthy human volunteers. Cold thermosensation was associated with low- and high-frequency oscillatory rhythms, both originating in operculo-insular regions. These results support further investigations of central cold processing using magnetoencephalography or EEG and the clinical utility of cold-evoked potentials for neurophysiological assessment of cold-related small-fiber function and damage.

scholarly journals Large-scale functional integration, rather than functional dissociation along dorsal and ventral streams, underlies visual perception and action

2019 ◽  
Author(s):  
Dipanjan Ray ◽  
Nilambari Hajare ◽  
Dipanjan Roy ◽  
Arpan Banerjee
Keyword(s):  
Visual Perception ◽  
Large Scale ◽  
Premotor Cortex ◽  
Functional Integration ◽  
Predictive Coding ◽  
Dorsal Stream ◽  
Brain Regions ◽  
Neural Pathways ◽  
Healthy Human ◽  
Mri Environment

AbstractVisual dual stream theory posits that two distinct neural pathways of specific functional significance originate from primary visual areas and reach the inferior temporal (ventral) and posterior parietal areas (dorsal). However, there are several unresolved questions concerning the fundamental aspects of this theory. For example, is the functional dissociation between ventral and dorsal stream driven by features in input stimuli or is it driven by categorical differences between visuo-perceptual and visuo-motor functions? Is the dual stream rigid or flexible? What is the nature of the interactions between two streams? We addressed these questions using fMRI recordings on healthy human volunteers and employing stimuli and tasks that can tease out the divergence between visuo-perceptual and visuo-motor models of dual stream theory. fMRI scans were repeated after seven practice sessions that were conducted in a non-MRI environment to investigate the effects of neuroplasticity. Brain activation analysis supports an input-based functional dissociation and existence of context-dependent neuroplasticity in dual stream areas. Intriguingly, premotor cortex activation was observed in the position perception task and distributed deactivated regions were observed in all perception tasks thus, warranting a network level analysis. Dynamic causal modelling (DCM) analysis incorporating activated and deactivated brain areas during perception tasks indicates that the brain dynamics during visual perception and actions could be interpreted within the framework of predictive coding. Effectively, the network level findings point towards the existence of more intricate context-driven functional networks selective of “what” and “where” information rather than segregated streams of processing along ventral and dorsal brain regions.

scholarly journals Large-scale Functional Integration, Rather than Functional Dissociation along Dorsal and Ventral Streams, Underlies Visual Perception and Action

2020 ◽  
Vol 32 (5) ◽  
pp. 847-861 ◽  
Author(s):  
Dipanjan Ray ◽  
Nilambari Hajare ◽  
Dipanjan Roy ◽  
Arpan Banerjee
Keyword(s):  
Visual Perception ◽  
Large Scale ◽  
Premotor Cortex ◽  
Functional Integration ◽  
Predictive Coding ◽  
Dorsal Stream ◽  
Brain Regions ◽  
Causal Modeling ◽  
Neural Pathways ◽  
Healthy Human

Visual dual-stream theory posits that two distinct neural pathways of specific functional significance originate from primary visual areas and reach the inferior temporal (ventral) and posterior parietal areas (dorsal). However, there are several unresolved questions concerning the fundamental aspects of this theory. For example, is the functional dissociation between ventral and dorsal stream driven by features in input stimuli or is it driven by categorical differences between visuoperceptual and visuomotor functions? Is the dual stream rigid or flexible? What is the nature of the interactions between the two streams? We addressed these questions using fMRI recordings on healthy human volunteers and employing stimuli and tasks that can tease out the divergence between visuoperceptual and visuomotor variants of dual-stream theory. fMRI scans were repeated after seven practice sessions that were conducted in a non-MRI environment to investigate the effects of neuroplasticity. Brain activation analysis supports an input-based functional dissociation and existence of context-dependent neuroplasticity in dual-stream areas. Intriguingly, premotor cortex activation was observed in the position perception task and distributed deactivated regions were observed in all perception tasks, thus warranting a network-level analysis. Dynamic causal modeling analysis incorporating activated and deactivated brain areas during perception tasks indicates that the brain dynamics during visual perception and actions could be interpreted within the framework of predictive coding. Effectively, the network-level findings point toward the existence of more intricate context-driven functional networks selective of “what” and “where” information rather than segregated streams of processing along ventral and dorsal brain regions.

Neurophysiological evaluation of healthy human anorectal sensation

2006 ◽  
Vol 291 (5) ◽  
pp. G950-G958 ◽  
Author(s):  
M. L. Harris ◽  
A. R. Hobson ◽  
S. Hamdy ◽  
D. G. Thompson ◽  
L. M. Akkermans ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Intraclass Correlation ◽  
Functional Gastrointestinal Disorders ◽  
Sensory Threshold ◽  
Rectal Sensation ◽  
Healthy Human ◽  
Afferent Pathways ◽  
Central Processing ◽  
Balloon Distension ◽  
Sensory Evoked

Patients with functional gastrointestinal disorders often demonstrate abnormal visceral sensation. Currently, rectal sensation is assessed by manual balloon distension or barostat. However, neither test is adaptable for use in the neurophysiological characterization of visceral afferent pathways by sensory evoked potentials. The aim of this study was to assess the reproducibility and quality of sensation evoked by electrical stimulation (ES) and rapid balloon distension (RBD) in the anorectum and to apply the optimum stimulus to examine the visceral afferent pathway with rectal evoked potentials. Healthy subjects ( n = 8, median age 33 yr) were studied on three separate occasions. Variability, tolerance, and stimulus characteristics were assessed with each technique. Overall ES consistently invoked pain and was chosen for measuring rectal evoked potential whereas RBD in all cases induced the strong urge to defecate. Rectal intraclass correlation coefficient (ICC) for ES and RBD (0.82 and 0.72, respectively) demonstrated good reproducibility at pain/maximum tolerated volume but not at sensory threshold. Only sphincter ICC for ES at pain showed acceptable between-study reproducibility (ICC 0.79). Within studies ICC was good (>0.6) for anorectal ES and RBD at both levels of sensation. All subjects reported significantly more unpleasantness during RBD than ES ( P < 0.01). This study demonstrates that ES and RBD are similarly reproducible. However, the sensations experienced with each technique differed markedly, probably reflecting differences in peripheral and/or central processing of the sensory input. This is of relevance in interpreting findings of neuroimaging studies of anorectal sensation and may provide insight into the physiological characteristics of visceral afferent pathways in health and disease.

Diurnal time course of pain perception in healthy humans

2006 ◽  
Vol 37 (01) ◽  
Author(s):  
CG Bachmann ◽  
C Harder ◽  
A Antal ◽  
P Baier ◽  
T Tings ◽  
...  
Keyword(s):  
Time Course ◽  
Pain Perception ◽  
Healthy Humans

Optometric Vision Therapy for Visual Deficits and Dysfunctions: A Suggested Model for Evidence-Based Practice

2015 ◽  
pp. 290-339
Keyword(s):  
Speech Therapy ◽  
Evidence Based Practice ◽  
Behavioural Therapy ◽  
Evidence Based ◽  
Neural Pathways ◽  
Central Processing ◽  
Visual Deficits ◽  
Visual Spatial ◽  
Functional Vision ◽  
Vision Therapy

Evidence from neural science supports a neuroplasticity thesis where the development and rehabilitation of functional neural pathways can be facilitated by management of biological factors, central processing and environmental interactions. Healthy eyes and clear sight are not themselves sufficient for efficient functional vision. How a person uses vision determines their operational skill. Efficient functional vision requires dynamic interactions between and within visual receptive and reflexive biology, acquired neural networks that serve basic visual inspection processes and visuo-cognitive operational patterns driving top down visual – spatial analysis and problem solving. This presentation is a review and discussion of evidence-based practice (EBP) principles that we utilise in clinical neuro-developmental and rehabilitative optometric vision therapy (OVT) for selected visual deficits and dysfunctions. OVT services, like other collaborative therapies such as cognitive behavioural therapy, speech therapy and occupational therapy, must progressively adapt to new knowledge and advancing technology through EBP. Clinical services directed at treatable neuro-developmental and acquired dynamic functional vision problems require the application of an emerging set of principles resulting from systematic logic and EBP related to the art and science of case analysis, practice management and OVT delivery.

Focal Mechanical Vibration Does not Change Laser-Pain Perception and Laser-Evoked Potentials: A Pilot Study

Pain Practice ◽  
2016 ◽  
Vol 17 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Costanza Pazzaglia ◽  
Filippo Camerota ◽  
Claudia Celletti ◽  
Ileana Minciotti ◽  
Elisa Testani ◽  
...  
Keyword(s):  
Pilot Study ◽  
Evoked Potentials ◽  
Pain Perception ◽  
Mechanical Vibration ◽  
Laser Evoked Potentials

Evoked potentials and central processing of visual information

1971 ◽  
Vol 11 ◽  
pp. 457-477 ◽  
Author(s):  
E. García Austt ◽  
W. Bun˜o ◽  
A. Vanzulli
Keyword(s):  
Evoked Potentials ◽  
Visual Information ◽  
Central Processing ◽  
Processing Of Visual Information

scholarly journals Both ongoing alpha and visually induced gamma oscillations show reliable diversity in their across-site phase-relations

2015 ◽  
Vol 113 (5) ◽  
pp. 1556-1563 ◽  
Author(s):  
Freek van Ede ◽  
Stan van Pelt ◽  
Pascal Fries ◽  
Eric Maris
Keyword(s):  
Phase Relation ◽  
Visual Stimulation ◽  
Low Frequency ◽  
Gamma Oscillations ◽  
Phase Relations ◽  
Neural Oscillations ◽  
High Signal ◽  
Noninvasive Methods ◽  
Healthy Human ◽  
Systems Neuroscience

Neural oscillations have emerged as one of the major electrophysiological phenomena investigated in cognitive and systems neuroscience. These oscillations are typically studied with regard to their amplitude, phase, and/or phase coupling. Here we demonstrate the existence of another property that is intrinsic to neural oscillations but has hitherto remained largely unexplored in cognitive and systems neuroscience. This pertains to the notion that these oscillations show reliable diversity in their phase-relations between neighboring recording sites (phase-relation diversity). In contrast to most previous work, we demonstrate that this diversity is restricted neither to low-frequency oscillations nor to periods outside of sensory stimulation. On the basis of magnetoencephalographic (MEG) recordings in humans, we show that this diversity is prominent not only for ongoing alpha oscillations (8–12 Hz) but also for gamma oscillations (50–70 Hz) that are induced by sustained visual stimulation. We further show that this diversity provides a dimension within electrophysiological data that, provided a sufficiently high signal-to-noise ratio, does not covary with changes in amplitude. These observations place phase-relation diversity on the map as a prominent and general property of neural oscillations that, moreover, can be studied with noninvasive methods in healthy human volunteers. This opens important new avenues for investigating how neural oscillations contribute to the neural implementation of cognition and behavior.

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