Prior to reading this article it was my belief that the purpose of dreaming (REM sleep) was to copy medium term (daily) memories from the hippocampus to long term memory in the cerebral cortex. REM sleep occurs in only 2 of the 3 orders of mammals: placentals (which include humans and rodents) and marsupials. Egg laying mammals such as the spiny anteater do not dream and have a much different brain structure.
I find it a mystery why memories are played back at high speed in reverse order, with excitations in the cortex preceding those in the hippocampus, and that this occurs during non REM sleep. Perhaps this is part of a feedback loop to erase memories from the hippocampus after they have been copied. -- Matt Mahoney, [EMAIL PROTECTED] ----- Original Message ---- From: Bob Mottram <[EMAIL PROTECTED]> To: [email protected] Sent: Tuesday, December 19, 2006 8:45:34 AM Subject: Re: [agi] Brain memory Map Article - I was also reading that article. The place cell phenomena has been known for many years. For a long time I've thought that sleep might be used for something other than just down time and cellular repair, and this research does seem to confirm that sleep has some functional role. It's interesting that memories are played back in reverse, which might suggest some form of back-propogation in which the brain is searching for the most likely causes of interesting events. On 18/12/06, James Ratcliff <[EMAIL PROTECTED]> wrote: Interesting article on how they really exhaustively mapped a rats brain... "The researchers could interpret the memories through electrodes inserted into the rats' brains, including into special neurons in the hippocampus. These neurons are known as "place cells" because each is activated when the rat passes a specific location, as if they were part of a map in the brain. The activation is so reliable that one can tell where a rat is in its cage by seeing which of its place cells is firing." http://www.nytimes.com/2006/12/18/science/18memory.html?ref=us James Ratcliff _______________________________________ James Ratcliff - http://falazar.com New Torrent Site, Has TV and Movie Downloads! http://www.falazar.com/projects/Torrents/tvtorrents_show.php __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?list_id=303 This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?list_id=303 ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?list_id=303
