Did I Really See That? The Complex Relationship Between the Visual Stimulus and Visual Perception

Laryngeal imaging uses optical and electronic means to visualize the larynx. Understanding some of the issues related to how the human visual system operates and how imaging systems interact with the visual system can help clarify some of the artifacts that arise from these technologies. This article describes how the visual system can construct coherent perceptions from limited information, how it adjusts to current situations, and how the perception of any one part of the image depends upon the light levels around each point. In particular, the limited field of view and stroboscopic nature of the images can lead to many distortions from laryngeal imaging. This article also describes the way that imaging systems sample the image, and the lack of stability inherent in an imaging system. The article concludes with some observations and recommendations to improve the ability to use imaging systems in the diagnosis of laryngeal pathology.