Editing Visual short-term memory (section)

===Slot models===
A prominent class of model proposes that observers are limited by the total number of items which can be encoded, either because the capacity of VSTM itself is limited.{{efn|e.g., {{harvnb |Cowan |2001}}; {{harvnb |Luck |Vogel |1997}}; {{harvnb |Pashler |1988}}.}} This type of model has obvious similarities to urn models used in probability theory.{{efn|See, for example, {{harvnb |Mendenhall |1967}}.{{Full citation needed|date=May 2022}}<!-- There are a number of works by people named Mendenhall published in 1967. -->}} In essence, an urn model assumes that VSTM is restricted in storage capacity to only a few items, ''k'' (often estimated to lie in the range of three-to-five in adults, though fewer in children<ref>{{cite journal | last1 = Riggs | first1 = K.J. | last2 = McTaggart | first2 = J. | last3 = Simpson | first3 = A. | year = 2006 | title = Changes in the capacity of visual working memory in 5- to 10-year-olds | journal = Journal of Experimental Child Psychology | volume = 95 | issue = 1| pages = 18–26 | doi = 10.1016/j.jecp.2006.03.009 | pmid = 16678845 }}</ref>). The probability that a suprathreshold change will be detected is simply the probability that the change element is encoded in VSTM (i.e., ''k''/''N''). This capacity limit has been linked to the posterior parietal cortex, the activity of which initially increases with the number of stimuli in the arrays, but saturates at higher set-sizes.<ref>{{cite journal |doi=10.1038/nature02466 |pmid=15085133 |title=Capacity limit of visual short-term memory in human posterior parietal cortex |journal=Nature |volume=428 |issue=6984 |pages=751–754 |year=2004 |last1=Todd |first1=J. Jay |last2=Marois |first2=René |bibcode=2004Natur.428..751T |s2cid=4415712}}</ref> Although urn models are used commonly to describe performance limitations in VSTM,{{efn|e.g., {{harvnb |Luck |Vogel |1997}}; {{harvnb |Pashler |1988}}; {{harvnb |Sperling |1960}}.}} it is only recently that the actual structure of items stored has been considered. Luck and colleagues have reported a series of experiments designed specifically to elucidate the structure of information held in VSTM.<ref>{{cite journal | last1 = Luck | first1 = S.J. | last2 = Vogel | first2 = E.K. | year = 1997 | title = The capacity of visual working memory for features and conjunctions | journal = Nature | volume = 390 | issue = 6657| pages = 279–281 | doi = 10.1038/36846 | pmid = 9384378 | bibcode = 1997Natur.390..279L | s2cid = 205025290 }}</ref> This work provides evidence that items stored in VSTM are coherent objects, and not the more elementary features of which those objects are composed.