Seeing Beyond the Human: Challenges and Advances in Animal Studies of Visual Consciousness

Studying visual consciousness in animals has provided important insights into its neural mechanisms, due to the availability of precise neural recording and perturbation techniques. On one hand, animals can serve as models to understand the neural underpinnings of visual consciousness and its disorders in humans. On the other hand, investigating the presence of consciousness and comparing perceptual experiences across various species are fascinating in their own right. In this chapter, we review experimental approaches and key findings regarding each topic. We argue that to understand the neural mechanisms of visual consciousness, we first need to establish perceptual report and no-report paradigms in humans that accurately reflect their subjective experiences. Then, we need to transfer these paradigms to animals and combine them with high-throughput electrophysiology and cell- or pathway-specific perturbations. As we review several experimental approaches including visual illusions, visual masking, bistable perception paradigms, and other behavioral metrics to investigate conscious perception in different animals, we argue that the combined evidence from these approaches would give the most refined picture of how they subjectively experience the visual world. Finally, we present results from non-human primate studies concerning the neural circuitry underlying visual consciousness disorders such as blindsight and spatial neglect.