scholarly journals A voxel-wise encoding model for VR-navigation maps view-direction tuning at 7T-fMRI

2019 ◽  
Vol 19 (10) ◽  
pp. 162b
Author(s):  
Matthias Nau ◽  
Tobias Navarro Schröder ◽  
Markus Frey ◽  
Christian F. Doeller
Keyword(s):  
Direction Tuning ◽  
7T Fmri

scholarly journals Neural Substrates of Human Fear Generalization: A 7T-fMRI Investigation

NeuroImage ◽  
2021 ◽  
pp. 118308
Author(s):  
Ashley A. Huggins ◽  
Carissa N. Weis ◽  
Elizabeth A. Parisi ◽  
Kenneth P. Bennett ◽  
Vladimir Miskovic ◽  
...  
Keyword(s):  
Neural Substrates ◽  
Fear Generalization ◽  
7T Fmri

scholarly journals Discharge Properties of MST Neurons That Project to the Frontal Pursuit Area in Macaque Monkeys

2005 ◽  
Vol 94 (2) ◽  
pp. 1084-1090 ◽  
Author(s):  
Anne K. Churchland ◽  
Stephen G. Lisberger
Keyword(s):  
Optic Flow ◽  
Action Potentials ◽  
Rhesus Monkeys ◽  
Statistical Significance ◽  
Image Motion ◽  
Antidromic Activation ◽  
Medial Superior Temporal ◽  
Mst Neurons ◽  
Direction Tuning ◽  
And Control

We have used antidromic activation to determine the functional discharge properties of neurons that project to the frontal pursuit area (FPA) from the medial-superior temporal visual area (MST). In awake rhesus monkeys, MST neurons were considered to be activated antidromically if they emitted action potentials at fixed, short latencies after stimulation in the FPA and if the activation passed the collision test. Antidromically activated neurons ( n = 37) and a sample of the overall population of MST neurons ( n = 110) then were studied during pursuit eye movements across a dark background and during laminar motion of a large random-dot texture and optic flow expansion and contraction during fixation. Antidromically activated neurons showed direction tuning during pursuit (25/37), during laminar image motion (21/37), or both (16/37). Of 27 neurons tested with optic flow stimuli, 14 showed tuning for optic flow expansion ( n = 10) or contraction ( n = 4). There were no statistically significant differences in the response properties of the antidromically activated and control samples. Preferred directions for pursuit and laminar image motion did not show any statistically significant biases, and the preferred directions for eye versus image motion in each sample tended to be equally divided between aligned and opposed. There were small differences between the control and antidromically activated populations in preferred speeds for laminar motion and optic flow; these might have reached statistical significance with larger samples of antidromically activated neurons. We conclude that the population of MST neurons projecting to the FPA is highly diverse and quite similar to the general population of neurons in MST.

scholarly journals Spatially structured inhibition defined by polarized parvalbumin interneuron axons promotes head direction tuning

2021 ◽  
Vol 7 (25) ◽  
pp. eabg4693
Author(s):  
Yangfan Peng ◽  
Federico J. Barreda Tomas ◽  
Paul Pfeiffer ◽  
Moritz Drangmeister ◽  
Susanne Schreiber ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Pyramidal Cells ◽  
Brain Regions ◽  
Head Direction ◽  
Spatial Connectivity ◽  
Parvalbumin Interneurons ◽  
Parvalbumin Interneuron ◽  
Network Simulations ◽  
Fast Spiking ◽  
Direction Tuning

In cortical microcircuits, it is generally assumed that fast-spiking parvalbumin interneurons mediate dense and nonselective inhibition. Some reports indicate sparse and structured inhibitory connectivity, but the computational relevance and the underlying spatial organization remain unresolved. In the rat superficial presubiculum, we find that inhibition by fast-spiking interneurons is organized in the form of a dominant super-reciprocal microcircuit motif where multiple pyramidal cells recurrently inhibit each other via a single interneuron. Multineuron recordings and subsequent 3D reconstructions and analysis further show that this nonrandom connectivity arises from an asymmetric, polarized morphology of fast-spiking interneuron axons, which individually cover different directions in the same volume. Network simulations assuming topographically organized input demonstrate that such polarized inhibition can improve head direction tuning of pyramidal cells in comparison to a “blanket of inhibition.” We propose that structured inhibition based on asymmetrical axons is an overarching spatial connectivity principle for tailored computation across brain regions.

scholarly journals A predictive focus of gain modulation encodes target trajectories in insect vision

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Steven D Wiederman ◽  
Joseph M Fabian ◽  
James R Dunbier ◽  
David C O’Carroll
Keyword(s):  
Target Location ◽  
Insect Vision ◽  
Gain Modulation ◽  
Brain Hemispheres ◽  
Contrast Gain ◽  
Enhanced Sensitivity ◽  
Neuronal Mechanisms ◽  
New Locations ◽  
Direction Tuning ◽  
Predictive Processes

When a human catches a ball, they estimate future target location based on the current trajectory. How animals, small and large, encode such predictive processes at the single neuron level is unknown. Here we describe small target-selective neurons in predatory dragonflies that exhibit localized enhanced sensitivity for targets displaced to new locations just ahead of the prior path, with suppression elsewhere in the surround. This focused region of gain modulation is driven by predictive mechanisms, with the direction tuning shifting selectively to match the target’s prior path. It involves a large local increase in contrast gain which spreads forward after a delay (e.g. an occlusion) and can even transfer between brain hemispheres, predicting trajectories moved towards the visual midline from the other eye. The tractable nature of dragonflies for physiological experiments makes this a useful model for studying the neuronal mechanisms underlying the brain’s remarkable ability to anticipate moving stimuli.

A massive 7T fMRI dataset to bridge cognitive neuroscience and artificial intelligence

2021 ◽  
Author(s):  
Emily J. Allen ◽  
Ghislain St-Yves ◽  
Yihan Wu ◽  
Jesse L. Breedlove ◽  
Jacob S. Prince ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Cognitive Neuroscience ◽  
7T Fmri

scholarly journals SA71. A Multimodal Magnetoencephalography, 7T fMRI Stroop, and 7T MRS Spectroscopy Study in First-Episode Psychosis

2017 ◽  
Vol 43 (suppl_1) ◽  
pp. S138-S139
Author(s):  
Timothy Gawne ◽  
Gregory Overbeek ◽  
Jefferey Killen ◽  
David White ◽  
Meredith Reid ◽  
...  
Keyword(s):  
First Episode Psychosis ◽  
First Episode ◽  
Spectroscopy Study ◽  
Episode Psychosis ◽  
7T Fmri

scholarly journals Measurement of ultra‐fast signal progression related to face processing by 7T fMRI

2020 ◽  
Vol 41 (7) ◽  
pp. 1754-1764
Author(s):  
Uk‐Su Choi ◽  
Yul‐Wan Sung ◽  
Seiji Ogawa
Keyword(s):  
Face Processing ◽  
7T Fmri
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