Cognitive psychology examines how humans receive information from the environment, process it, and translate it into behavior. Because science is grounded in empirical measurement, it does not address the “soul” as a measurable entity, but rather focuses on observable behavior and the cognitive processes inferred from it. Cognition includes sensation, perception, attention, memory, and learning, and enables researchers to understand past behavior, explain present actions, and predict future behavior. In the context of user experience, these principles form the foundation for understanding user actions and anticipating their responses to interfaces, based on the assumption that a significant portion of human behavior is pre-determined and operates at a non-conscious level.

Perception and attention are limited and selective resources: not all environmental stimuli are processed, and the cognitive system filters information according to relevance, intensity, context, and cognitive load. The senses register physical energy, yet perceptual experience is subjective and often prone to distortion. Attention may be conscious or unconscious, focused or broad, and is influenced both by stimulus-driven properties (bottom-up processes) and by the user’s goals and expectations (top-down processes). Understanding these mechanisms is essential for effective system design: reducing cognitive load, limiting options, emphasizing relevant information, and using motion and salient stimuli judiciously all contribute to a clear, predictable, and cognitively aligned user experience.