scholarly journals Predictive encoding of motion begins in the primate retina

2020 ◽  
Author(s):  
Belle Liu ◽  
Arthur Hong ◽  
Fred Rieke ◽  
Michael B. Manookin
Keyword(s):  
Natural Selection ◽  
Moving Objects ◽  
Translational Motion ◽  
Macaque Monkey ◽  
Neural Mechanisms ◽  
Motion Prediction ◽  
Theoretical Limit ◽  
Motion Patterns ◽  
Natural Vision ◽  
Motion Types

ABSTRACTSurvival in the natural environment often relies on an animal’s ability to quickly and accurately predict the trajectories of moving objects. Motion prediction is primarily understood in the context of translational motion, but the environment contains other types of behaviorally salient motion, such as that produced by approaching or receding objects. However, the neural mechanisms that detect and predictively encode these motion types remain unclear. Here, we address these questions in the macaque monkey retina. We report that four of the parallel output pathways in the primate retina encode predictive information about the future trajectory of moving objects. Predictive encoding occurs both for translational motion and for higher-order motion patterns found in natural vision. Further, predictive encoding of these motion types is nearly optimal with transmitted information approaching the theoretical limit imposed by the stimulus itself. These findings argue that natural selection has emphasized encoding of information that is relevant for anticipating future properties of the environment.

scholarly journals Modulation frequency as a cue for auditory speed perception

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170673 ◽  
Author(s):  
Irene Senna ◽  
Cesare V. Parise ◽  
Marc O. Ernst
Keyword(s):  
Motion Perception ◽  
Moving Objects ◽  
Modulation Frequency ◽  
Temporal Frequency ◽  
Neural Mechanisms ◽  
Auditory Motion ◽  
Motion Vision ◽  
Speed Perception ◽  
Spatio Temporal ◽  
Motion Aftereffects

Unlike vision, the mechanisms underlying auditory motion perception are poorly understood. Here we describe an auditory motion illusion revealing a novel cue to auditory speed perception: the temporal frequency of amplitude modulation (AM-frequency), typical for rattling sounds. Naturally, corrugated objects sliding across each other generate rattling sounds whose AM-frequency tends to directly correlate with speed. We found that AM-frequency modulates auditory speed perception in a highly systematic fashion: moving sounds with higher AM-frequency are perceived as moving faster than sounds with lower AM-frequency. Even more interestingly, sounds with higher AM-frequency also induce stronger motion aftereffects. This reveals the existence of specialized neural mechanisms for auditory motion perception, which are sensitive to AM-frequency. Thus, in spatial hearing, the brain successfully capitalizes on the AM-frequency of rattling sounds to estimate the speed of moving objects. This tightly parallels previous findings in motion vision, where spatio-temporal frequency of moving displays systematically affects both speed perception and the magnitude of the motion aftereffects. Such an analogy with vision suggests that motion detection may rely on canonical computations, with similar neural mechanisms shared across the different modalities.

scholarly journals Response profiles to texture border patterns in area V1

2000 ◽  
Vol 17 (3) ◽  
pp. 421-436 ◽  
Author(s):  
HANS-CHRISTOPH NOTHDURFT ◽  
JACK L. GALLANT ◽  
DAVID C. VAN ESSEN
Keyword(s):  
Receptive Field ◽  
Single Cells ◽  
Macaque Monkey ◽  
Neural Mechanisms ◽  
Center Line ◽  
Response Modulation ◽  
Cell Patterns ◽  
Response Profiles ◽  
Homogeneous Regions ◽  
Line Elements

Cells in area V1 of the anesthetized macaque monkey were stimulated with large texture patterns composed of homogeneous regions of line elements (texels) with different orientations. To human observers, such patterns appear to segregate, with the percept of sharp boundaries between texture regions. Our objective was to investigate whether the boundaries are reflected in the responses of single cells in V1. We measured responses to individual texels at different distances from the texture border. For each cell, patterns of optimally or orthogonally orientated texels were adjusted so that only one texel fell into the receptive field and all other texels fell in the visually unresponsive regions outside. In 37 out of 156 neurons tested (24%), texels immediately adjacent to a texture border evoked reliably larger responses than identical texels farther away from the border. In 17 neurons (11%), responses to texels near the border were relatively reduced. Border enhancement effects were generally stronger than border attenuation effects. When tested with four different border configurations (two global orientations and two edge polarities), many cells showed reliable effects for only one or two configurations, consistent with cells encoding information about the orientation of the texture border or its location with respect to the segmented region. Across the sample, enhancement effects were similar for all texture borders. Modulation by the texture surround was predominantly suppressive; even the responses near texture borders were smaller than those to a single line. We compared these results with the results of a popout test in which the line in the receptive field was surrounded by homogeneous texture fields either orthogonal or parallel to the center line. The patterns of response modulation and the temporal onset of differential responses were similar in the two tests, suggesting that the two perceptual phenomena are mediated by similar neural mechanisms.

Type Synthesis of Parallel Mechanisms With Multiple Operation Modes

2006 ◽  
Author(s):  
Xianwen Kong ◽  
Cle´ment M. Gosselin ◽  
Pierre-Luc Richard
Keyword(s):  
Parallel Mechanism ◽  
Translational Motion ◽  
Parallel Mechanisms ◽  
Motion Pattern ◽  
Type Synthesis ◽  
Motion Patterns ◽  
Operation Modes ◽  
Multiple Operation ◽  
Spherical Motion ◽  
General Method

There are usually several motion patterns having the same DOF (degree of freedom). For example, planar motion, spherical motion, and spatial translation are motion patterns with 3-DOF. An f-DOF parallel mechanism with multiple operation modes is a parallel mechanism that can generate different motion patterns with f DOF. Up to now, no method has been proposed for the type synthesis of parallel mechanisms with multiple operation modes. This paper presents a general method for the type synthesis of parallel mechanisms with multiple operation modes. Using the proposed approach, 3-DOF parallel mechanisms with both spherical and translational modes, i.e., parallel mechanisms generating both the spherical motion pattern and the spatial translational motion pattern, are generated systematically. A large number of parallel mechanisms with both spherical and translational modes are obtained.

Visual interpretation of known objects in constrained scenes

1992 ◽  
Vol 337 (1281) ◽  
pp. 361-370 ◽  
Keyword(s):  
Object Recognition ◽  
Visual Perception ◽  
Machine Vision ◽  
Recent Work ◽  
Three Dimensional ◽  
Neural Mechanisms ◽  
Visual Interpretation ◽  
Natural Vision ◽  
Analogue Models ◽  
Dynamic Filters

Recent work on the visual interpretation of traffic scenes is described which relies heavily on a priori knowledge of the scene and position of the cam era, and expectations about the shapes of vehicles and their likely movements in the scene. Knowledge is represented in the computer as explicit three-dimensional geometrical models, dynamic filters, and descriptions of behaviour. Model-based vision, based on reasoning with analogue models, avoids many of the classical problems in visual perception: recognition is robust against changes in the image of shape, size, colour and illumination. The three-dimensional understanding of the scene which results also deals naturally with occlusion, and allows the behaviour of vehicles to be interpreted. The experiments with machine vision raise questions about the part played by perceptual context for object recognition in natural vision, and the neural mechanisms which might serve such a role.

scholarly journals Cubic LSTMs for Video Prediction

2019 ◽  
Vol 33 ◽  
pp. 8263-8270 ◽  
Author(s):  
Hehe Fan ◽  
Linchao Zhu ◽  
Yi Yang
Keyword(s):  
Learning Communities ◽  
Moving Objects ◽  
Short Term Memory ◽  
Robot Learning ◽  
Motion Prediction ◽  
Short Term ◽  
The Core ◽  
Long Short Term Memory ◽  
Real World Datasets ◽  
Video Prediction

Predicting future frames in videos has become a promising direction of research for both computer vision and robot learning communities. The core of this problem involves moving object capture and future motion prediction. While object capture specifies which objects are moving in videos, motion prediction describes their future dynamics. Motivated by this analysis, we propose a Cubic Long Short-Term Memory (CubicLSTM) unit for video prediction. CubicLSTM consists of three branches, i.e., a spatial branch for capturing moving objects, a temporal branch for processing motions, and an output branch for combining the first two branches to generate predicted frames. Stacking multiple CubicLSTM units along the spatial branch and output branch, and then evolving along the temporal branch can form a cubic recurrent neural network (CubicRNN). Experiment shows that CubicRNN produces more accurate video predictions than prior methods on both synthetic and real-world datasets.

scholarly journals SPATIAL MOTION PATTERNS: ACTION MODELS FROM SEMI-DENSE TRAJECTORIES

2014 ◽  
Vol 28 (07) ◽  
pp. 1460011 ◽  
Author(s):  
THANH PHUONG NGUYEN ◽  
ANTOINE MANZANERA ◽  
MATTHIEU GARRIGUES ◽  
NGOC-SON VU
Keyword(s):  
Moving Objects ◽  
Computation Time ◽  
Local Binary Patterns ◽  
Point Particle ◽  
Spatial Motion ◽  
High Definition ◽  
Motion Patterns ◽  
Action Model ◽  
Global Representation ◽  
Action Models

A new action model is proposed, by revisiting local binary patterns (LBP) for dynamic texture models, applied on trajectory beams calculated on the video. The use of semi-dense trajectory field allows to dramatically reduce the computation support to essential motion information, while maintaining a large amount of data to ensure robustness of statistical bag of features action models. A new binary pattern, called Spatial Motion Pattern (SMP) is proposed, which captures self-similarity of velocity around each tracked point (particle), along its trajectory. This operator highlights the geometric shape of rigid parts of moving objects in a video sequence. SMPs are combined with basic velocity information to form the local action primitives. Then, a global representation of a space × time video block is provided by using hierarchical blockwise histograms, which allows to efficiently represent the action as a whole, while preserving a certain level of spatiotemporal relation between the action primitives. Inheriting from the efficiency and the invariance properties of both the semi-dense tracker Video extruder and the LBP-based representations, the method is designed for the fast computation of action descriptors in unconstrained videos. For improving both robustness and computation time in the case of high definition video, we also present an enhanced version of the semi-dense tracker based on the so-called super particles, which reduces the number of trajectories while improving their length, reliability and spatial distribution.

The Propagation of Star-Shaped Brittle Cracks

2010 ◽  
Vol 77 (4) ◽  
Author(s):  
Nazile B. Rassoulova
Keyword(s):  
Original Problem ◽  
Analytic Solution ◽  
Closed Form Solution ◽  
Form Solution ◽  
Theoretical Limit ◽  
Motion Patterns ◽  
Stress Intensity Coefficient ◽  
Careful Choice ◽  
Elastic Thin Plate ◽  
Self Similar

The paper studies the dynamical propagation of star-shaped cracks symmetrically arranged in an elastic thin plate, subjected to the action of instantly applied, comprehensively (uniformly) stretching stresses, which implies a self-similar problem with homogeneous stresses and velocities of particles. Occurrence of such motion patterns is established through experiments. By using the Smirnov–Sobolev functional-invariant solutions method and a careful choice of mappings, the problem is reduced to some boundary value problem of the theory of complex variable functions, and exact analytic solution of the original problem, including a closed-form solution for important stress intensity coefficient near the end of the crack, is derived. We also establish a fundamental theoretical limit imposed on the number of cracks—there has to be at least three cracks.

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