Neuropsychology seeks to understand how the brain produces behavior and mental processes through its structure and neural networks. It emerged in the mid-20th century from ideas about localization of brain function and hemispheric specialization. Neuropsychological assessment involves objective tests sensitive to brain injury effects, measuring domains like attention, memory, language and executive functions. Tests sample different cognitive abilities and may reveal impairments related to damage in specific brain regions like the frontal lobes. The field has advanced assessment techniques and established clinical neuropsychology as a specialty.