The word “dementia” is an umbrella term used to describe a set of symptoms, including impairment in memory, reasoning, judgment, language and other thinking skills. Dementia begins gradually in most cases, worsens over time and significantly impairs a person’s abilities in work, social interactions and relationships.
Often, memory loss is one of the first or more recognizable signs of dementia. Other early signs may include:
-Asking the same questions repeatedly
-Forgetting common words when speaking
-Mixing words up — saying “bed” instead of “table,” for example
-Taking longer to complete familiar tasks, such as following a recipe
-Misplacing items in inappropriate places, such as putting a wallet in a kitchen drawer
-Getting lost while walking or driving around a familiar neighborhood
-Undergoing sudden changes in mood or behavior for no apparent reason
-Becoming less able to follow directions

Diseases that cause progressive damage to the brain — and consequently result in dementia — include:
-Alzheimer’s disease, the most common cause of dementia
-Vascular dementia (multi-infarct dementia)
-Frontotemporal dementia
-Lewy body dementia

Each of these conditions has a somewhat different disease process (pathology). Memory impairment isn’t always the first sign of disease, and the type of memory problems may vary.

To Dream, perhaps to Learn?

A Harvard study suggested that dreaming may reactivate and reorganize recently learned material, improving memory and boosting performance. The subjects were 99 healthy college students who agreed to avoid alcohol, caffeine, and drugs for at least 24 hours prior to the experiment. All the volunteers demonstrated normal sleep patterns before enrolling in the study.
Each of the subjects spent an hour learning how to navigate through a complex three-dimensional maze-like puzzle. After the training period, half of the students were allowed to nap for 90 minutes, while the others read or relaxed. Following a lunch break, all the volunteers tackled the virtual maze again. The only students whose performance substantially improved were the few who dreamed about the maze during their naps. Although the dreams didn’t actually depict solutions to the puzzle, the researchers believe they show how the dreaming brain can reorganize and consolidate memories, resulting in better performance on learned tasks. And all the amazing dreams occurred early in NREM sleep.