Psychology is a broad field that studies phenomena such as sensation, perception, mental health, social behavior, cognition, behavior, psychological development, emotions, memory and other mental functions and their manifestations. The physiological processes underlying the psyche are studied in the fields of physiological psychology, neurology and neuropsychology.
Cognition is a broad term that deals with organisms' ability to gather, process, store and respond to knowledge. Perceiving, thinking, speaking, understanding, feeling emotions, memorizing, recalling memories and judging are all cognitive phenomena. Attention, reasoning, learning and problem solving are also phenomena studied within the field of cognitive psychology.
Sensation and perception are fundamental concepts in psychology. Sensation underlies organisms' ability to experience external reality, while perception allows organisms to interpret external stimuli. Perception is a cognitive phenomenon.
Certain senses are tactile, meaning that contact with stimuli is necessary in order to sense the stimuli. Smell, taste and touch are the three tactile senses. Smell and taste are chemical senses, meaning that they intercept chemical stimuli from the environment and send the information to the brain for perceptual processing, such as identification, judgment and psychological response. Touch is a sense that is based on the nervous system making contact with stimuli. Vision is that ability to sense light, and hearing is the ability so sense vibrations and pressure changes.