Nature explores why our aging brains succumb to insomnia and forgetfulness at the same time:
Ageing is associated with the gradual loss of brain cells, sleep disturbances and declining memory function, but how these factors are related to each other has been unclear.
Neuroscientist Bryce Mander at the University of California, Berkeley, and his colleagues recruited 33 healthy adults — 18 around the age of 20, and 15 ranging from late sixties to late seventies — all with normal mental function, and asked them to memorize a list of word pairs.
The participants were asked to recall some of the word pairs ten minutes later, then left to sleep overnight…
In keeping with earlier studies, the older adults performed less well than the younger ones on the memory test, and showed significant reductions in the slow brain waves associated with deep sleep.
The extent of deep-sleep disruption was related to the degree of memory impairment….
It is well established that sleep strengthens newly formed memories, and slow brain waves are thought to enhance the transfer of information from the hippocampus, a brain structure that is crucial to memory formation, to other parts of the brain for long-term storage.
Mander and colleagues’ findings suggest that deterioration of the medial prefrontal cortex diminishes the slow waves that occur during deep sleep.
No *wonder* I’m so absent-minded. It’s the sleep.