Cognitive deficit, also known as cognitive impairment is an inclusive term to describe any characteristic that acts as a barrier to cognitive performance. The term may describe deficits in global intellectual performance, such as mental retardation, it may describe specific deficits in cognitive abilities (learning disorders, dyslexia), or it may describe drug-induced cognitive/memory impairment, such as that seen with alcohol and the benzodiazepines. Cognitive deficits may be congenital or caused by environmental factors such as brain injuries, neurological disorders, or mental illness.