NOVA scienceNOW Sleep13:16Video duration: 13:16 Aired: 07/10/07 Rating: TV-GVideo has closed captioning. Why do we need sleep? Part of the answer may be to strengthen memories. Add to WatchlistShare:Share this video on FacebookShare this video on TwitterShare this video via EmailShare this video on Google PlusEmbed Code for this videoEmbed CodeNOVA scienceNOWSleepPremiere Date: July 10, 2007, 4:01 a.m.Width in pixels px Height in pixels px Please copy this text to your clipboard×CloseProblems Playing Video ?Report a problemClosed CaptioningReport a ProblemBefore you submit an error, please consult our Troubleshooting Guide.Type of ErrorVideo doesn't loadVideo loads, but doesn't playVideo jumps back/forwardOnly audio is streamingSponsorship playback errorOtherPlease add more detailsCancelSubmit ReportYour report has been successfully submitted. Thank you for helping us improve PBS Video.Close×Close Funding for NOVA ScienceNOW is provided by the National Science Foundation and the Alfred P. Sloan Foundation.