The proposed programs has three main objectives: 1) to understand the organization and neurological foundations of human memory; 2) to understand the ways in which memory impairment can occur and also the best ways to measure memory impairment; and 3) to specify the effects of electroconvulsive therapy on memory. Nineteen separate projects are proposed in six specific areas: 1) characterizing the neuroanatomical and neuropsychological manifestations of memory impairment; 2) anterograde amnesia: the nature of impaired memory; 3) preserved learning in amnesia; 4) retrograde amnesia: memory for remote events; 5) electroconvulsive therapy and memory impairment: clinical studies; and 6) experimental amnesia in the mouse: electroconvulsive shock. The subject populations are memory-impaired patients with neurological injury or disease, patients with circumscribed vascular lesions of frontal cortex, psychiatric patients prescribed ECT, and control subjects for these groups including depressed inpatients not receiving ECT, alcoholics, and healthy subjects. The 19 proposed projects include a quantitative neuroradiological evaluation (CT scan) of patients with Korsakoff's syndrome and two control groups; a series of studies on a newly established population of patients with frontal lobe injury designed to illuminate the contribution of the frontal lobes to normal memory functions; a test of the hypothesis that human amnesia disproportionately affects spatial memory; a test of the idea that amnesic patients can learn and retain novel associations in a normal fashion, although the knowledge can be expressed only implicitly (i.e., unconsciously); a search for the limits of preserved learning capacity in amnesia using tests of adaptation level and other judgment tasks; a study of the status of retrograde amnesia in non-Korsakoff amnesic patients; a study of transient global amnesia, which is an incompletely understood neurological syndrome; and studies of the objective and subjective memory impairment associated with electroconvulsive therapy. Overall, this work should answer questions about how memory is organized in the brain, about how to quantify and classify memory impairment, and about the risks of ECT to memory.