Hypoxia leads to decrease in hemodynamic responses of visual cortex

2021 ◽  
Author(s):  
Karolina Bejm ◽  
Stanislaw Wojtkiewicz ◽  
Zanna Pastuszak ◽  
Adam Liebert
Keyword(s):  
Visual Cortex ◽  
Hemodynamic Responses

scholarly journals Fast Hemodynamic Responses in the Visual Cortex of the Awake Mouse

2013 ◽  
Vol 33 (46) ◽  
pp. 18343-18351 ◽  
Author(s):  
M. A. Pisauro ◽  
N. T. Dhruv ◽  
M. Carandini ◽  
A. Benucci
Keyword(s):  
Visual Cortex ◽  
Hemodynamic Responses

Relative latency and temporal variability of hemodynamic responses at the human primary visual cortex

NeuroImage ◽  
2018 ◽  
Vol 164 ◽  
pp. 194-201 ◽  
Author(s):  
Fa-Hsuan Lin ◽  
Jonathan R. Polimeni ◽  
Jo-Fu Lotus Lin ◽  
Kevin W.-K. Tsai ◽  
Ying-Hua Chu ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Temporal Variability ◽  
Hemodynamic Responses

scholarly journals Anticipatory Changes in Regional Cerebral Hemodynamics: A New Role for Dopamine?

2009 ◽  
Vol 101 (6) ◽  
pp. 2738-2740 ◽  
Author(s):  
Can Ozan Tan
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neural Activity ◽  
Cerebral Hemodynamics ◽  
Physiological Data ◽  
Cerebral Microcirculation ◽  
Hemodynamic Responses ◽  
On Demand ◽  
Demand Allocation

Recently, adaptively timed, anticipatory changes in hemodynamic responses, independent of neural activity, were described in primate primary visual cortex. Task-related properties of these responses point to a possible link between regional cerebral microcirculation and dopaminergic signaling. In this report, this link is elaborated on the basis of known physiological data and further experiments are proposed to test the possible role of dopamine in task-dependent, “on-demand” allocation of metabolic resources.

scholarly journals Investigation of human visual cortex responses to flickering light using functional near infrared spectroscopy and constrained ICA

2014 ◽  
Vol 07 (06) ◽  
pp. 1450031 ◽  
Author(s):  
Nguyen Duc Thang ◽  
Vo Van Toi ◽  
Le Giang Tran ◽  
Nguyen Huynh Minh Tam ◽  
Lan Anh Trinh
Keyword(s):  
Infrared Spectroscopy ◽  
Visual Cortex ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Hemoglobin Concentration ◽  
Visual Sensitivity ◽  
Hemodynamic Responses ◽  
Functional Near Infrared Spectroscopy ◽  
Physiological Factors ◽  
Flickering Light

The human visual sensitivity to the flickering light has been under investigation for decades. The finding of research in this area can contribute to the understanding of human visual system mechanism and visual disorders, and establishing diagnosis and treatment of diseases. The aim of this study is to investigate the effects of the flickering light to the visual cortex by monitoring the hemodynamic responses of the brain with the functional near infrared spectroscopy (fNIRS) method. Since the acquired fNIRS signals are affected by physiological factors and measurement artifacts, constrained independent component analysis (cICA) was applied to extract the actual fNIRS responses from the obtained data. The experimental results revealed significant changes (p < 0.0001) of the hemodynamic responses of the visual cortex from the baseline when the flickering stimulation was activated. With the uses of cICA, the contrast to noise ratio (CNR), reflecting the contrast of hemodynamic concentration between rest and task, became larger. This indicated the improvement of the fNIRS signals when the noise was eliminated. In subsequent studies, statistical analysis was used to infer the correlation between the fNIRS signals and the visual stimulus. We found that there was a slight decrease of the oxygenated hemoglobin concentration (about 5.69%) over four frequencies when the modulation increased. However, the variations of oxy and deoxy-hemoglobin were not statistically significant.

scholarly journals Influence of contrast-reversing frequency on the amplitude and spatial distribution of visual cortex hemodynamic responses

2019 ◽  
Vol 10 (12) ◽  
pp. 6296
Author(s):  
Karolina Bejm ◽  
Stanisław Wojtkiewicz ◽  
Piotr Sawosz ◽  
Maciej Perdziak ◽  
Zanna Pastuszak ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Visual Cortex ◽  
Hemodynamic Responses

scholarly journals Task-related hemodynamic responses in human early visual cortex are modulated by task difficulty and behavioral performance

2021 ◽  
Author(s):  
Charlie S. Burlingham ◽  
Minyoung Ryoo ◽  
Zvi N. Roth ◽  
Saghar Mirbagheri ◽  
David J. Heeger ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Task Difficulty ◽  
Visual Stimulation ◽  
Field Potential ◽  
Cardiac Activity ◽  
Orientation Discrimination ◽  
Behavioral Performance ◽  
Hemodynamic Responses ◽  
Early Visual Cortex ◽  
And Behavior

Early visual cortex exhibits widespread hemodynamic responses in the absence of visual stimulation, which are entrained to the timing of a task and not predicted by local spiking or local field potential (LFP). Such task-related responses ("TRRs") covary with reward magnitude and physiological signatures of arousal. It is unknown, however, if TRRs change on a trial-to-trial basis according to behavioral performance and task difficulty. If so, this would suggest that TRRs reflect arousal on a trial-to-trial timescale and covary with critical task and behavioral variables. We measured fMRI-BOLD responses in the early visual cortex of human observers performing an orientation discrimination task consisting of separate easy and hard runs of trials. Stimuli were presented in a small portion of one hemifield, but the fMRI response was measured in the ipsilateral hemisphere, far from the stimulus representation and focus of spatial attention. TRRs scaled in amplitude with task difficulty, behavioral accuracy, reaction time, and lapses across trials. These modulations were not explained by the influence of respiration, cardiac activity, or head movement on the fMRI signal. Similar modulations with task difficulty and behavior were observed in pupil size. These results suggest that TRRs reflect arousal and behavior on the timescale of individual trials.

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