scholarly journals Stereoscopic depth adaptation from binocularly correlated versus anti-correlated noise: Test of an efficient coding theory of stereopsis

2020 ◽  
Vol 166 ◽  
pp. 60-71 ◽  
Author(s):  
Frederick A.A. Kingdom ◽  
Karl-Christopher Yared ◽  
Paul B. Hibbard ◽  
Keith A. May
Keyword(s):  
Coding Theory ◽  
Stereoscopic Depth ◽  
Correlated Noise ◽  
Efficient Coding ◽  
Noise Test

scholarly journals Scene statistics and noise determine the relative arrangement of receptive field mosaics

2021 ◽  
Vol 118 (39) ◽  
pp. e2105115118
Author(s):  
Na Young Jun ◽  
Greg D. Field ◽  
John Pearson
Keyword(s):  
Neural Coding ◽  
Coding Theory ◽  
Receptive Fields ◽  
Optimal Arrangement ◽  
Efficient Coding ◽  
Natural Stimuli ◽  
Signal Stimulus ◽  
Theoretical Predictions ◽  
On And Off Pathways ◽  
Contrast Response

Many sensory systems utilize parallel ON and OFF pathways that signal stimulus increments and decrements, respectively. These pathways consist of ensembles or grids of ON and OFF detectors spanning sensory space. Yet, encoding by opponent pathways raises a question: How should grids of ON and OFF detectors be arranged to optimally encode natural stimuli? We investigated this question using a model of the retina guided by efficient coding theory. Specifically, we optimized spatial receptive fields and contrast response functions to encode natural images given noise and constrained firing rates. We find that the optimal arrangement of ON and OFF receptive fields exhibits a transition between aligned and antialigned grids. The preferred phase depends on detector noise and the statistical structure of the natural stimuli. These results reveal that noise and stimulus statistics produce qualitative shifts in neural coding strategies and provide theoretical predictions for the configuration of opponent pathways in the nervous system.

scholarly journals An Efficient Coding Technique for Stochastic Processes

Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 65
Author(s):  
Jesús E. Garca ◽  
Verónica A. González-López ◽  
Gustavo H. Tasca ◽  
Karina Y. Yaginuma
Keyword(s):  
Dna Sequences ◽  
Coding Theory ◽  
Transition Probabilities ◽  
Real Data ◽  
Finite Alphabet ◽  
Real Problem ◽  
Huffman Code ◽  
Efficient Coding ◽  
Codeword Length ◽  
Hand Modeling

In the framework of coding theory, under the assumption of a Markov process (Xt) on a finite alphabet A, the compressed representation of the data will be composed of a description of the model used to code the data and the encoded data. Given the model, the Huffman’s algorithm is optimal for the number of bits needed to encode the data. On the other hand, modeling (Xt) through a Partition Markov Model (PMM) promotes a reduction in the number of transition probabilities needed to define the model. This paper shows how the use of Huffman code with a PMM reduces the number of bits needed in this process. We prove the estimation of a PMM allows for estimating the entropy of (Xt), providing an estimator of the minimum expected codeword length per symbol. We show the efficiency of the new methodology on a simulation study and, through a real problem of compression of DNA sequences of SARS-CoV-2, obtaining in the real data at least a reduction of 10.4%.

scholarly journals Active efficient coding explains the development of binocular vision and its failure in amblyopia

2020 ◽  
Vol 117 (11) ◽  
pp. 6156-6162
Author(s):  
Samuel Eckmann ◽  
Lukas Klimmasch ◽  
Bertram E. Shi ◽  
Jochen Triesch
Keyword(s):  
Eye Movements ◽  
Binocular Vision ◽  
Coding Theory ◽  
Critical Period ◽  
Receptive Fields ◽  
Efficient Coding ◽  
Coding Efficiency ◽  
Vision Development ◽  
Neural Representations ◽  
Active Binocular Vision

The development of vision during the first months of life is an active process that comprises the learning of appropriate neural representations and the learning of accurate eye movements. While it has long been suspected that the two learning processes are coupled, there is still no widely accepted theoretical framework describing this joint development. Here, we propose a computational model of the development of active binocular vision to fill this gap. The model is based on a formulation of the active efficient coding theory, which proposes that eye movements as well as stimulus encoding are jointly adapted to maximize the overall coding efficiency. Under healthy conditions, the model self-calibrates to perform accurate vergence and accommodation eye movements. It exploits disparity cues to deduce the direction of defocus, which leads to coordinated vergence and accommodation responses. In a simulated anisometropic case, where the refraction power of the two eyes differs, an amblyopia-like state develops in which the foveal region of one eye is suppressed due to inputs from the other eye. After correcting for refractive errors, the model can only reach healthy performance levels if receptive fields are still plastic, in line with findings on a critical period for binocular vision development. Overall, our model offers a unifying conceptual framework for understanding the development of binocular vision.

scholarly journals An efficient coding theory for a dynamic trajectory predicts non-uniform allocation of entorhinal grid cells to modules

2017 ◽  
Vol 13 (6) ◽  
pp. e1005597 ◽  
Author(s):  
Noga Mosheiff ◽  
Haggai Agmon ◽  
Avraham Moriel ◽  
Yoram Burak
Keyword(s):  
Coding Theory ◽  
Grid Cells ◽  
Efficient Coding ◽  
Dynamic Trajectory

Can Behavioral Speech-In-Noise Tests Improve the Quality of Hearing Aid Fittings?

2011 ◽  
Vol 7 (1) ◽  
pp. 8-14
Author(s):  
Robert Moore ◽  
Susan Gordon-Hickey
Keyword(s):  
Working Memory ◽  
Speech Perception ◽  
Performance Test ◽  
Hearing Aid ◽  
Speech Perception In Noise ◽  
Speech In Noise ◽  
Acceptable Noise Level ◽  
Perceptual Performance ◽  
Noise Test

The purpose of this article is to propose 4 dimensions for consideration in hearing aid fittings and 4 tests to evaluate those dimensions. The 4 dimensions and tests are (a) working memory, evaluated by the Revised Speech Perception in Noise test (Bilger, Nuetzel, & Rabinowitz, 1984); (b) performance in noise, evaluated by the Quick Speech in Noise test (QSIN; Killion, Niquette, Gudmundsen, Revit, & Banerjee, 2004); (c) acceptance of noise, evaluated by the Acceptable Noise Level test (ANL; Nabelek, Tucker, & Letowski, 1991); and (d) performance versus perception, evaluated by the Perceptual–Performance test (PPT; Saunders & Cienkowski, 2002). The authors discuss the 4 dimensions and tests in the context of improving the quality of hearing aid fittings.

Coding Theory

2004 ◽  
Author(s):  
San Ling ◽  
Chaoping Xing
Keyword(s):  
Coding Theory

The sense of presence in virtual environments:

2003 ◽  
Vol 15 (2) ◽  
pp. 69-71 ◽  
Author(s):  
Thomas W. Schubert
Keyword(s):  
Virtual Environments ◽  
Coding Theory ◽  
Model Building ◽  
Self Report ◽  
Survey Study ◽  
Spatial Presence ◽  
Component Structure ◽  
Sense Of Presence ◽  
Being There ◽  
Measure Sense

Abstract. The sense of presence is the feeling of being there in a virtual environment. A three-component self report scale to measure sense of presence is described, the components being sense of spatial presence, involvement, and realness. This three-component structure was developed in a survey study with players of 3D games (N = 246) and replicated in a second survey study (N = 296); studies using the scale for measuring the effects of interaction on presence provide evidence for validity. The findings are explained by the Potential Action Coding Theory of presence, which assumes that presence develops from mental model building and suppression of the real environment.

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