Theories of dream function since the identification of REM sleep include:
Hobsons and McCarleys 1977 activation-synthesis hypothesis, which proposed "a functional role for dreaming sleep in promoting some aspect of the learning process...." In 2010 a Harvard study was published showing experimental evidence that dreams were correlated with improved learning.Cricks and Mitchisons 1983 "reverse learning" theory, which states that dreams are like the cleaning-up operations of computers when they are offline, removing (suppressing) parasitic nodes and other "junk" from the mind during sleep.Hartmanns 1995 proposal that dreams serve a "quasi-therapeutic" function, enabling the dreamer to process trauma in a safe place.Revonsuos 2000 threat simulation hypothesis, whose premise is that during much of human evolution, physical and interpersonal threats were serious, giving reproductive advantage to those who survived them. Dreaming aided survival by replicating these threats and providing the dreamer with practice in dealing with them.Eaglemans and Vaughns 2021 defensive activation theory, which says that, given the brains neuroplasticity, dreams evolved as a visual hallucinatory activity during sleeps extended periods of darkness, busying the occipital lobe and thereby protecting it from possible appropriation by other, non-vision, sense operations. Religious and other cultural contexts
Dreams figure prominently in major world religions. The dream experience for early humans, according to one interpretation, gave rise to the notion of a human "soul," a central element in much religious thought.
In the more severe form, hair loss can occur in patches all over the body and might be accompanied by crusting, pain, enlarged lymph nodes, and deep skin infections. Typically, animals become infected through nursing from their mother. The transmission of these mites from mother to pup is normal (which is why the mites are normal inhabitants of the dogs skin), but some individuals are sensitive to the mites due to a cellular immune deficiency, underlying disease, stress, or malnutrition, which can lead to the development of clinical demodectic mange. Some breeds appear to have an increased risk of mild cases as young dogs, including the Afghan Hound, American Staffordshire Terrier, Boston Terrier, Boxer, Chihuahua, Chow Chow, Shar-Pei, Collie, Dalmatian, Doberman Pinscher, Bulldog, French Bulldog, English Bull Terrier, Miniature Bull Terrier, German Shepherd, Great Dane, Old English Sheepdog, American Pit Bull Terrier, West Highland White Terrier, Rat Terrier, Yorkshire Terrier, Dachshund, and Pug. Cats
There are two types of demodectic mange in cats. Demodex cati causes follicular mange, similar to that seen in dogs, though it is much less common. Demodex gatoi is a more superficial form of mange, causes an itchy skin condition, and is contagious amongst cats. Other
Demodectic mange also occurs in other domestic and wild animals, including captive pandas. Diagnosis
For demodectic mange, properly performed deep skin scrapings generally allow the veterinarian to identify the microscopic mites. Acetate tape impression with squeezing has recently found to be a more sensitive method to identify mites.