Reverse learning 3048571 215478437 2008-05-28T11:25:44Z DOI bot 6652755 Citation maintenance. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. '''Reverse learning''' is a [[neurobiology|neurobiological]] theory of [[dream]]s. [[Crick]] and [[Mitchinson]]'s (1983) reverse learning model likened the process of dreaming to a [[computer]] in that it was "off-line" during dreaming. During this phase, the brain supposedly sifts through information gathered throughout the day and throws out all unwanted material. According to the model, we dream in order to forget and this involves a process of "reverse learning." The [[Cerebral cortex|cortex]] cannot cope with the vast amount of information received throughout the day without developing "parasitic" thoughts that would disrupt the efficient organisation of [[memory]]. During [[REM sleep]], these unwanted connections in cortical networks are wiped out by impulses bombarding the cortex from [[subcortex|sub-cortical]] areas. ==Support for the theory of reverse learning== In the [[echidna]], a primitive egg-laying mammal that has no [[REM sleep]], there is a very enlarged frontal cortex (Allison et al, 1972). Crick and Mitchison argue that this excessive cortical development is necessary to store both adaptive memories and parasitic memories, which in more highly evolved animals are disposed of during REM sleep. ==Objections to the theory of reverse learning== One problem for reverse-learning theory is that [[dreams]] are often organized into clear [[narratives]] (stories). It is unclear why dreams would be organized in a [[systematic]] way if they consisted only of disposable [[parasitic]] thoughts. It is also unclear why babies [[sleep]] so much, because it seems they would have less to forget. Additionally, the [[brain]] of the [[echidna]] has far less folding than the brains of other [[mammals]], so has less surface area (the location of the [[neo-cortex]]). It may actually have less capacity for higher thought than that of other mammals, rather than more, as it's greater mas suggests. In response to these objections, Crick and Mitchison restricted their theory to apply only to dreams with bizarre imagery and no clear narrative ==References== *{{cite journal | author=Allison, T., Van Twyver, H. and Goff, W.R. | title=Sleep in mammals: ecological and constitutional correlates | journal=Archives of Italian Biology | volume=110 | year=1972 | pages=145–184}} *{{cite journal | author=Crick F and Mitchison G | title=The function of dream sleep | journal=Nature | volume=304 | issue=5922 | year=1983| pages=111–4 | pmid=6866101 | doi=10.1038/304111a0}} [[Category:Neurobiology]] {{neuroscience-stub}} {{psych-stub}}