Visual Perception and Cognitive Performance

The Warfighter in the modern battlespace has a predetermined, but ever-changing, set of tasks that must be performed. Performance on these tasks is affected strongly by the amount and quality of the visual input, as well as by the resultant visual perception and cognitive performance. Visual perception is defined as the mental organization and interpretation of the visual sensory information with the intent of attaining awareness and understanding of the local environment, e.g., objects and events. Cognition refers to the faculty for the human-like processing of this information and application of previously acquired knowledge (i.e., memory) to build understanding and initiate responses. Cognition involves attention, expectation, learning, memory, language, and problem solving. The direct physical stimuli for visual perception are the emitted or reflected quanta of light energy from objects in the visual environment that enters the eyes. It is important to understand that the resulting perception of the stimuli is not only a result of their physical properties (e.g., wavelength, intensity, and hue) but also of the changes induced by the transduction, filtering, and transformation of the physical input by the entire human visual system. This chapter explores some of the more important visual processes that contribute to visual perception and cognitive performance. These include brightness perception, size constancy, visual acuity (VA), contrast sensitivity, color discrimination, motion perception, depth perception and stereopsis. An analogous discussion of input via the auditory sense is discussed in Chapter 11, Auditory Perception and Cognitive Performance.