If you’ve ever met a person on the street and thought, “I know that person, but from where?” your memory lapse may be connected to how much sleep you had last night.

If you had been awake for 12 hours or more when you first met the person, your ability to retain that face in your memory may be impaired. The proper amount and quality of sleep helps us to learn new information and retain it, to process information efficiently and to consolidate memories.

Evidence that sleep is implicated in the consolidation of different kinds of memories has been mounting. Among the elderly, memory impairment and chronic insomnia are common complaints.

A study conducted by the Department of Behavioral Science, Max Stem Emek Yezreel College in Israel, sought to determine whether late-life insomnia might be associated with memory status. Two groups were studied: one of 50 older adult participants who were free of sleep disorders and 23 older adult insomniacs. The results showed that impairment of memory was associated with chronic insomnia. It was found that older people who suffered from late-life insomnia exhibited reduced performance in learning rate, and in temporal order judgment, as well as significantly reduced resistance to interference. The findings suggested that insomnia late in life may contribute to the decline in memory processing seen among the elderly.