The present invention provides methods for assessing episodic memory in a subject. Also provided are methods for assessing semantic memory in a subject. The present invention further provides methods for screening for an agent directed to treating, slowing down the progress of, attenuating the symptoms of, or preventing dementia characterized by episodic memory impairment. Additionally, the present invention provides methods for screening for an agent directed to treating, slowing down the progress of, attenuating the symptoms of, or preventing dementia characterized by semantic memory impairment. Finally, the present invention provides methods for measuring semantic memory in a subject.