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.

许多感觉系统利用并行的 ON 和 OFF 通路，分别表示刺激增加和减少。这些路径由跨越感官空间的 ON 和 OFF 探测器的集合或网格组成。然而，由对手通路编码提出了一个问题：应该如何安排 ON 和 OFF 检测器的网格以最佳地编码自然刺激？我们使用由高效编码理论指导的视网膜模型研究了这个问题。具体来说，我们优化了空间感受野和对比响应函数，以在给定噪声和受限发射率的情况下对自然图像进行编码。我们发现 ON 和 OFF 感受野的最佳排列表现出对齐和反对齐网格之间的过渡。首选相位取决于检测器噪声和自然刺激的统计结构。