Binocular Population Responses in the Early Visual System

Abstract

Binocular vision emerges from the convergence of monocular inputs in the primary visual cortex (V1), yet the specific mechanisms governing this integration remain unresolved. This dissertation addresses three fundamental questions: (1) How do subcortical and cortical circuits contribute to binocular vision, particularly in the transition from the lateral geniculate nucleus (LGN) to V1? (2) Does neural suppression in V1 serve as the initiating mechanism for binocular rivalry? (3) What laminar mechanisms underlie interocular conflict? The first chapter explores the pathway of binocular vision from the LGN to cortex. Neurophysiological recordings from the LGN examine how magnocellular, parvocellular, and koniocellular streams shape binocular processing in V1. The second chapter evaluates whether response suppression is a prerequisite for initiating binocular rivalry. Recordings from V1 while macaque subjects viewed binocular rivalry flash suppression (BRFS) reveal that response facilitation—not suppression—dominates at the onset of BRFS, suggesting that adaptation mechanisms drive rivalry initiation in this context. The third chapter investigates how V1 resolves interocular conflict across its laminar profile. Using laminar electrodes, we observed coherence-based mechanisms across the columnar microcircuit that occur with interocular conflict. Conflict between the eyes reduces interlaminar coherence, particularly between deep and superficial layers, offering a novel account of how V1 dynamically regulates binocular competition beyond changes in spiking activity. Together, these studies provide new insight into how binocular vision emerges from neural population activity across multiple processing stages, emphasizing the role of adaptation, population-level coherence, and cortical micro circuitry in shaping visual perception.