scholarly journals The Effects of Human Visual Sensory Stimuli on N1b Amplitude: An EEG Study

2020 ◽  
Vol 9 (9) ◽  
pp. 2837
Author(s):  
Damien Moore ◽  
Toshikazu Ikuta ◽  
Paul D. Loprinzi
Keyword(s):  
Visual Cortex ◽  
Visual Stimulation ◽  
Human Model ◽  
Sensory Stimuli ◽  
Neural Connections ◽  
Black And White ◽  
Adaptive Mechanisms ◽  
Eeg Data ◽  
Significant Difference ◽  
Stimulation Paradigm

Sensory systems are widely known to exhibit adaptive mechanisms. Vision is no exception to input dependent changes in its sensitivity. Recent animal work demonstrates enhanced connectivity between neurons in the visual cortex. The purpose of the present experiment was to evaluate a human model that noninvasively alters the amplitude of the N1b component in the visual cortex of humans by means of rapid visual stimulation. Nineteen participants (Mage = 24 years; 52.6% male) completed a rapid visual stimulation paradigm involving black and white reversal checkerboards presented bilaterally in the visual field. EEG data was collected during the visual stimulation paradigm, which consisted of four main phases, a pre-tetanus block, photic stimulus, early post-tetanus, and late post-tetanus. The amplitude of the N1b component of the pre-tetanus, early post-tetanus and late post-tetanus visual evoked potentials were calculated. Change in N1b amplitude was calculated by subtracting pre-tetanus N1b amplitude from early and late post-tetanus. Results demonstrated a significant difference between pre-tetanus N1b (M = −0.498 µV, SD = 0.858) and early N1b (M = −1.011 µV, SD = 1.088), t (18) = 2.761, p = 0.039, d = 0.633. No difference was observed between pre-tetanus N1b and late N1b (p = 0.36). In conclusion, our findings suggest that it is possible to induce changes in the amplitude of the visually evoked potential N1b waveform in the visual cortex of humans non-invasively. Additional work is needed to corroborate that the potentiation of the N1b component observed in this study is due to similar mechanisms essential to prolonged strengthened neural connections exhibited in cognitive structures of the brain observed in prior animal research. If so, this will allow for the examination of strengthened neural connectivity and its interaction with multiple human sensory stimuli and behaviors.

scholarly journals Enhanced Alpha-oscillations in Visual Cortex during Anticipation of Self-generated Visual Stimulation

2014 ◽  
Vol 26 (11) ◽  
pp. 2540-2551 ◽  
Author(s):  
Max-Philipp Stenner ◽  
Markus Bauer ◽  
Patrick Haggard ◽  
Hans-Jochen Heinze ◽  
Ray Dolan
Keyword(s):  
Visual Cortex ◽  
Visual Stimulation ◽  
Sensory Information ◽  
Sensory Stimuli ◽  
Forward Models ◽  
Alpha Oscillations ◽  
Time Frequency ◽  
Sensory Attenuation ◽  
Sensory Neural ◽  
Motor Actions

The perceived intensity of sensory stimuli is reduced when these stimuli are caused by the observer's actions. This phenomenon is traditionally explained by forward models of sensory action–outcome, which arise from motor processing. Although these forward models critically predict anticipatory modulation of sensory neural processing, neurophysiological evidence for anticipatory modulation is sparse and has not been linked to perceptual data showing sensory attenuation. By combining a psychophysical task involving contrast discrimination with source-level time–frequency analysis of MEG data, we demonstrate that the amplitude of alpha-oscillations in visual cortex is enhanced before the onset of a visual stimulus when the identity and onset of the stimulus are controlled by participants' motor actions. Critically, this prestimulus enhancement of alpha-amplitude is paralleled by psychophysical judgments of a reduced contrast for this stimulus. We suggest that alpha-oscillations in visual cortex preceding self-generated visual stimulation are a likely neurophysiological signature of motor-induced sensory anticipation and mediate sensory attenuation. We discuss our results in relation to proposals that attribute generic inhibitory functions to alpha-oscillations in prioritizing and gating sensory information via top–down control.

scholarly journals Behavioral-state modulation of inhibition is context-dependent and cell type specific in mouse visual cortex

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Janelle MP Pakan ◽  
Scott C Lowe ◽  
Evelyn Dylda ◽  
Sander W Keemink ◽  
Stephen P Currie ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Pyramidal Neurons ◽  
Visual Stimulation ◽  
Inhibitory Neurons ◽  
Behavioral State ◽  
Visual Responses ◽  
Cell Type ◽  
Sensory Stimuli ◽  
Context Dependent

Cortical responses to sensory stimuli are modulated by behavioral state. In the primary visual cortex (V1), visual responses of pyramidal neurons increase during locomotion. This response gain was suggested to be mediated through inhibitory neurons, resulting in the disinhibition of pyramidal neurons. Using in vivo two-photon calcium imaging in layers 2/3 and 4 in mouse V1, we reveal that locomotion increases the activity of vasoactive intestinal peptide (VIP), somatostatin (SST) and parvalbumin (PV)-positive interneurons during visual stimulation, challenging the disinhibition model. In darkness, while most VIP and PV neurons remained locomotion responsive, SST and excitatory neurons were largely non-responsive. Context-dependent locomotion responses were found in each cell type, with the highest proportion among SST neurons. These findings establish that modulation of neuronal activity by locomotion is context-dependent and contest the generality of a disinhibitory circuit for gain control of sensory responses by behavioral state.

Sex differences in a frequency graded visual stimulation paradigm for fMRI are limited to striate visual cortex and suggest a frequency dependence

NeuroImage ◽  
2000 ◽  
Vol 11 (5) ◽  
pp. S737 ◽  
Author(s):  
Christian Kaufmann ◽  
Benno Pütz ◽  
Gregor K. Elbel ◽  
Christoff Gössl ◽  
Dorothee P. Auer
Keyword(s):  
Sex Differences ◽  
Visual Cortex ◽  
Frequency Dependence ◽  
Visual Stimulation ◽  
Stimulation Paradigm

Racial Disparity in Immediate Breast Reconstruction; a Gap That is not Closing

2021 ◽  
pp. 229255032110555
Author(s):  
Mahdi Malekpour ◽  
Sean Devitt ◽  
Joseph DeSantis ◽  
Christian Kauffman
Keyword(s):  
Propensity Score ◽  
Breast Reconstruction ◽  
Racial Disparity ◽  
Standard Of Care ◽  
Immediate Breast Reconstruction ◽  
P Value ◽  
National Cancer Database ◽  
Black Females ◽  
Black And White ◽  
Significant Difference

Background: Immediate breast reconstruction (IBR) is offered as part of the standard-of-care to females undergoing mastectomy. Racial disparity in IBR has been previously reported with a longstanding call for its elimination, though unknown if this goal is achieved. The aim of this study was to examine the current association between race and IBR and to investigate whether racial disparity is diminishing. Methods: Data was extracted from the National Cancer Database (NCDB) from 2004 to 2016. All variables in the database were controlled so that the comparison would be made solely between Black and White females. We also analyzed the trend in racial disparity to see if there has been a change from 2004 to 2016 after several calls for healthcare equality. Results: After propensity score matching, 69,084 White females were compared to 69,084 Black females. There was a statistically significant difference between the rate of IBR and race (23,386 [33.9%] in White females vs 20,850 [30.2%] in Black females, P-value  < .001). Despite a twofold increase in the rate of IBR in both White and Black females, a persistent gap of about 4% was observed over the study period, which translates to more than 2,500 Black females not receiving IBR. Conclusions: Using the NCDB database, a racial disparity was identified for IBR between White and Black females from 2004 and 2016. Unfortunately, the gap between the groups remained constant over this 13-year period.

Hematological condition of breeding bulls after a long winter period of operation in the conditions of the Udmurt Republic

2022 ◽  
pp. 67-73
Author(s):  
A. Abilov ◽  
A. Azhmyakov ◽  
I. Novgorodova ◽  
N. Bogolyubova
Keyword(s):  
Red Blood Cells ◽  
Reference Values ◽  
Blood Cells ◽  
Hematological Parameters ◽  
White Blood Cells ◽  
Winter Period ◽  
Black And White ◽  
Significant Difference ◽  
White Breed ◽  
Udmurt Republic

Purpose: to study hematological parameters of blood in bulls-producers of dairy breeds on the day of semen collection in the Udmurt Republic after a long winter period of operation, depending on the breeds, age and place of selection.Materials and methods. The work was performed at the Federal Research Center for Animal Husbandry named after Academy Member L. K. Ernst on the basis of AO "Udmurtplem" of the Udmurt Republic in the period from 2020 to 2021 on dairy bulls (n=20) aged 15-69 months, including a purebred Holstein breed of domestic selection (n=6), a Holstein black-and-white breed of European selection (the Netherlands, n=6), a black-and-white breed with blood transfusion on Holsteins on at the level of 94-98% (n=8). The content of white blood cells, red blood cells, hemoglobin and hematocrit, depending on age and breed, was studied on the ABC VET hematological analyzer on the day of taking the seed.Results. It was found that on average, in 20 bulls aged 15-69 months, the level of white blood cells was at the level of reference values of 8.8±0.25 x 109/l, red blood cells 10.3 x 1012/l, which is 50% more than the reference values. The concentration of hemoglobin is 128.0±2.92 g/l, hematocrit is on average 54.3%, with a norm of 24-46%. Breeding bulls at a reliable level, differing in age, showed that some animals had high indicators for red blood cells of 10.3±0.26 x 102, for hematocrit of 54.3% against 24-46% of reference values. Also, according to hematological indicators, there was a tendency to increase the concentration of hemoglobin and hematocrit in European-bred bulls.Conclusion. The study of the variability in hematological parameters depending on the selection showed that there is no significant difference in leukocytes and all indicators are at the level of reference values, and in erythrocytes more than 50% than the highest indicators. The highest hemoglobin values were at the level of 141-156 g/l instead of 128 g/l according to the highest reference values. Hematocrit also showed high max values in all groups in comparison with the reference values of 59-66% versus 46% in the norm. It is necessary when analyzing hematological blood parameters in addition to the average statistical indicators (M+m) also, monitor the variability (min-max) in order to obtain more objective information.

scholarly journals Gender-specific modulation of short-term neuroplasticity in the visual cortex induced by transcranial direct current stimulation

2008 ◽  
Vol 25 (1) ◽  
pp. 77-81 ◽  
Author(s):  
LEILA CHAIEB ◽  
ANDREA ANTAL ◽  
WALTER PAULUS
Keyword(s):  
Sex Differences ◽  
Visual Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cortical Excitability ◽  
Gonadal Hormones ◽  
Study Data ◽  
Short Term ◽  
Direct Current Stimulation ◽  
Significant Difference

Transcranial direct current stimulation (tDCS) is a non-invasive method of modulating levels of cortical excitability. In this study, data gathered over a number of previously conducted experiments before and after tDCS, has been re-analyzed to investigate correlations between sex differences with respect to neuroplastic effects. Visual evoked potentials (VEPs), phosphene thresholds (PTs), and contrast sensitivity measurements (CSs) are used as indicators of the excitability of the primary visual cortex. The data revealed that cathodally induced excitability effects 10 min post stimulation with tDCS, showed no significant difference between genders. However, stimulation in the anodal direction revealed sex-specific effects: in women, anodal stimulation heightened cortical excitability significantly when compared to the age-matched male subject group. There was no significant difference between male and female subjects immediately after stimulation. These results indicate that sex differences exist within the visual cortex of humans, and may be subject to the influences of modulatory neurotransmitters or gonadal hormones which mirror short-term neuroplastic effects.

scholarly journals Thalamic inputs determine functionally distinct gamma bands in mouse primary visual cortex

2020 ◽  
Author(s):  
Nicolò Meneghetti ◽  
Chiara Cerri ◽  
Elena Tantillo ◽  
Eleonora Vannini ◽  
Matteo Caleo ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Information ◽  
Narrow Band ◽  
Broad Band ◽  
Gamma Band ◽  
Neuron Network ◽  
Sensory Stimuli ◽  
Thalamic Input ◽  
Visual Contrast

AbstractGamma band is known to be involved in the encoding of visual features in the primary visual cortex (V1). Recent results in rodents V1 highlighted the presence, within a broad gamma band (BB) increasing with contrast, of a narrow gamma band (NB) peaking at ∼60 Hz suppressed by contrast and enhanced by luminance. However, the processing of visual information by the two channels still lacks a proper characterization. Here, by combining experimental analysis and modeling, we prove that the two bands are sensitive to specific thalamic inputs associated with complementary contrast ranges. We recorded local field potentials from V1 of awake mice during the presentation of gratings and observed that NB power progressively decreased from low to intermediate levels of contrast. Conversely, BB power was insensitive to low levels of contrast but it progressively increased going from intermediate to high levels of contrast. Moreover, BB response was stronger immediately after contrast reversal, while the opposite held for NB. All the aforementioned dynamics were accurately reproduced by a recurrent excitatory-inhibitory leaky integrate-and-fire network, mimicking layer IV of mouse V1, provided that the sustained and periodic component of the thalamic input were modulated over complementary contrast ranges. These results shed new light on the origin and function of the two V1 gamma bands. In addition, here we propose a simple and effective model of response to visual contrast that might help in reconstructing network dysfunction underlying pathological alterations of visual information processing.Significance StatementGamma band is a ubiquitous hallmark of cortical processing of sensory stimuli. Experimental evidence shows that in the mouse visual cortex two types of gamma activity are differentially modulated by contrast: a narrow band (NB), that seems to be rodent specific, and a standard broad band (BB), observed also in other animal models.We found that narrow band correlates and broad band anticorrelates with visual contrast in two complementary contrast ranges (low and high respectively). Moreover, BB displayed an earlier response than NB. A thalamocortical spiking neuron network model reproduced the aforementioned results, suggesting they might be due to the presence of two complementary but distinct components of the thalamic input into visual cortical circuitry.

scholarly journals Functional selectivity and specific connectivity of inhibitory neurons in primary visual cortex

2018 ◽  
Author(s):  
Petr Znamenskiy ◽  
Mean-Hwan Kim ◽  
Dylan R. Muir ◽  
Maria Florencia Iacaruso ◽  
Sonja B. Hofer ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Pyramidal Cells ◽  
Fine Tuning ◽  
Inhibitory Neurons ◽  
Local Network ◽  
Cortical Circuits ◽  
Sensory Stimuli ◽  
Excitatory Neurons ◽  
Strong Excitation

In the cerebral cortex, the interaction of excitatory and inhibitory synaptic inputs shapes the responses of neurons to sensory stimuli, stabilizes network dynamics1 and improves the efficiency and robustness of the neural code2–4. Excitatory neurons receive inhibitory inputs that track excitation5–8. However, how this co-tuning of excitation and inhibition is achieved by cortical circuits is unclear, since inhibitory interneurons are thought to pool the inputs of nearby excitatory cells and provide them with non-specific inhibition proportional to the activity of the local network9–13. Here we show that although parvalbumin-expressing (PV) inhibitory cells in mouse primary visual cortex make connections with the majority of nearby pyramidal cells, the strength of their synaptic connections is structured according to the similarity of the cells’ responses. Individual PV cells strongly inhibit those pyramidal cells that provide them with strong excitation and share their visual selectivity. This fine-tuning of synaptic weights supports co-tuning of inhibitory and excitatory inputs onto individual pyramidal cells despite dense connectivity between inhibitory and excitatory neurons. Our results indicate that individual PV cells are preferentially integrated into subnetworks of inter-connected, co-tuned pyramidal cells, stabilising their recurrent dynamics. Conversely, weak but dense inhibitory connectivity between subnetworks is sufficient to support competition between them, de-correlating their output. We suggest that the history and structure of correlated firing adjusts the weights of both inhibitory and excitatory connections, supporting stable amplification and selective recruitment of cortical subnetworks.

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