Brain activity or several experiences we encounter during the day are replayed at fast-forward speed while we sleep. The researchers say that the brain stores only that information in the memory pockets which is significant. The key result is that the sleep replay helps to strengthen the microscopic connections between nerve cells that are active. This process is deemed critical for consolidation of memories. For a peaceful life, goodnight’s sleep is utmost important. A bad night’s sleep which is experienced either by healthy people or by people affected with schizophrenia or Alzheimer’s disease often leads to impaired mental function.