'''Sparse distributed memory''' is a mathematical model of human long-term memory that was introduced by [[Pentti Kanerva]] in 1988. It is used for storing and retrieving large amounts(<math>2^1000</math> [[bits]]) of information without focusing on the accuracy of the information. It uses patterns to serve as [[memory addressaddresses]]es, where information is retrieved based on similarities between addresses. Memory addresses are all in a list even if they are not related, but are only retrieved based on similar content between themselves.<ref name=book>{{cite book|last=Kanerva|first=Pentti|title=Sparse Distributed Memory|year=1988|publisher=The MIT Press|isbn=978-0262111324}}</ref>
==Formula==
The general formula is <math>2^n</math> where ''n'' is the number of dimensions of the space, and <math>2^n</math> is the number of feasible memory items.<ref name=book></ref>
==Definition==
Sparse Distributed Memory is a mathematical representation of human memory, and since human memory is complex, Sparse Distributed Memory uses [[Clustering high-dimensional data|high-dimensional space]] to help model the large amounts of memory that humans.<ref name=psu>{{cite web|title=Sparse Distributed Memory and Related Models|url=http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.2.8403&rep=rep1&type=pdf|publisher=Pennsylvania State University|accessdate=3 November 2011|author=Pentti Kanerva|year=1993}}</ref> It utilizes the [[Hamming distance]] to measure mismatched bits and read back data between the original write address and one near it.<ref name=stanford>{{cite web|title=Sparse Distributed Memory: Principles and Operation|url=ftp://reports.stanford.edu/pub/cstr/reports/csl/tr/89/400/CSL-TR-89-400.pdf|publisher=Stanford University|accessdate=1 November 2011|coauthors=M. J. Flynn, P. Kanerva, and N. Bhadkamkar|date=December 1989}}</ref> Human memory has a tendency to congregate memories based on similarities between them(although they may not be related), such as firetrucks are red and apples are red.<ref name=ship>{{cite web|title=General Psychology|url=http://webspace.ship.edu/cgboer/memory.html|publisher=Shippensburg University|author=C. George Boeree|year=2002}}</ref>
