Correction

In the article “Transcranial Direct Current Stimulation during Sleep Improves Declarative Memory,” by Lisa Marshall, Matthias Mölle, Manfred Hallschmid, and Jan Born, which appeared on pages 9985-9992 of the November 3, 2004 issue, an incorrect stimulation parameter was inadvertently given in the third sentence of the abstract and in the second sentence of the fourth paragraph of Materials and Methods. In those two sentences, current strength (0.26 mA) is meant, rather than current density (0.26 mA/cm²).