Agnosia is a neurological disorder characterized by the impaired ability to recognize objects, persons, sounds, shapes, or smells despite intact primary sensory functions. This recognition deficit is specific to particular sensory modalities, leading to various types such as visual, auditory, or tactile agnosia. Crucially, for a diagnosis of agnosia, the basic sensory input required for recognition must be intact. For instance, in visual agnosia, the individual's eyesight must be normal. Prosopagnosia, a specific type of visual agnosia, is defined by the inability to recognize familiar faces and/or learn new faces. The term is derived from the Greek words 'prosopon' (face) and 'gnosis' (knowledge).