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

Coding Perceptual Decisions: From Single Units to Emergent Signaling Properties in Cortical Circuits

2020 ◽  
Vol 6 (1) ◽  
pp. 387-409
Author(s):  
Kristine Krug
Keyword(s):  
Spatial Distribution ◽  
Visual Cortex ◽  
Functional Properties ◽  
Sensory Neurons ◽  
Single Neurons ◽  
Cortical Circuits ◽  
Task Context ◽  
Complex Interactions ◽  
Correlated Activity ◽  
Primate Visual Cortex

Spiking activity in single neurons of the primate visual cortex has been tightly linked to perceptual decisions. Any mechanism that reads out these perceptual signals to support behavior must respect the underlying neuroanatomy that shapes the functional properties of sensory neurons. Spatial distribution and timing of inputs to the next processing levels are critical, as conjoint activity of precursor neurons increases the spiking rate of downstream neurons and ultimately drives behavior. I set out how correlated activity might coalesce into a micropool of task-sensitive neurons signaling a particular percept to determine perceptual decision signals locally and for flexible interarea transmission depending on the task context. As data from more and more neurons and their complex interactions are analyzed, the space of computational mechanisms must be constrained based on what is plausible within neurobiological limits. This review outlines experiments to test the new perspectives offered by these extended methods.

scholarly journals Spatial Distribution of Contextual Interactions in Primary Visual Cortex and in Visual Perception

2000 ◽  
Vol 84 (4) ◽  
pp. 2048-2062 ◽  
Author(s):  
Mitesh K. Kapadia ◽  
Gerald Westheimer ◽  
Charles D. Gilbert
Keyword(s):  
Spatial Distribution ◽  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Cortical Neurons ◽  
Receptive Fields ◽  
Human Perception ◽  
Spatial Arrangement ◽  
Orthogonal Axis ◽  
V1 Neurons ◽  
Contextual Interactions

To examine the role of primary visual cortex in visuospatial integration, we studied the spatial arrangement of contextual interactions in the response properties of neurons in primary visual cortex of alert monkeys and in human perception. We found a spatial segregation of opposing contextual interactions. At the level of cortical neurons, excitatory interactions were located along the ends of receptive fields, while inhibitory interactions were strongest along the orthogonal axis. Parallel psychophysical studies in human observers showed opposing contextual interactions surrounding a target line with a similar spatial distribution. The results suggest that V1 neurons can participate in multiple perceptual processes via spatially segregated and functionally distinct components of their receptive fields.

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.

Types and spatial distribution of vasoactive intestinal polypeptide (VIP)-containing synapses in the rat visual cortex

1988 ◽  
Vol 178 (3) ◽  
pp. 207-217 ◽  
Author(s):  
Ferenc Haj�s ◽  
Karl Zilles ◽  
Axel Schleicher ◽  
Mih�ly K�lm�n
Keyword(s):  
Spatial Distribution ◽  
Visual Cortex ◽  
Vasoactive Intestinal Polypeptide ◽  
Intestinal Polypeptide

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.

Spatial distribution of inhibitory synaptic connections during development of ferret primary visual cortex

2004 ◽  
Vol 160 (4) ◽  
pp. 496-509 ◽  
Author(s):  
Bingzhong Chen ◽  
Kaoutar Boukamel ◽  
Joseph P.-Y. Kao ◽  
Birgit Roerig
Keyword(s):  
Spatial Distribution ◽  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Synaptic Connections
Sign in / Sign up

Export Citation Format

Share Document