<!-- Deleted image removed: [[File:fourshapesexp.png|thumb|alt=An example of four colored shapes and two black letters.|An example of the stimuli found in Treisman et al. (1982).]] -->In order to test the statementnotion that featuresattention areplays independenta invital therole earlyin preattentivevisual stageperception, Treisman and Schmidt (1982) designed an experiment to show that features may exist independently of one another early in whichprocessing. participantsParticipants arewere shown a picture involving four shapesobjects andhidden by two black numbers. The display was flashed for one-fifth of a second.Afterfollowed the display,by a random-dot masking field that appeared on screen to eliminate “any residual perception that might remain after the stimuli were turned off”.<ref>Cognitive Psychology, E. Bruce Goldstein, P 105</ref> TheParticipants task of participants waswere to report the black numbers first,they followedsaw byat whateach colored___location shapeswhen theythe sawshapes athad fourpreviously locationsbeen. The results of this experiment verified Treisman and Schmidt's hypothesis. In 18% of trials, participants reported seeing shapes “made up of a combination of features from two different stimuli”,<ref>Cognitive Psychology, E. Bruce Goldstein, P 105</ref> even when the stimuli had great differences.; Thisthis is often referred to as an [[illusory conjunction]], an often occurring illusion people experience during visual search. While people can typically remember the presence of an objectSpecifically, theyillusory often forget its ___location or color. Theyconjunctions occur in various situations;. forFor example, you may identify a passing person wearing a red shirt and yellow hat and very quickly transform him or her into one wearing a yellow shirt and red hat. The Feature integration theory canprovides explainexplanation for illusory conjunctions; –because infeatures Treisman’sexist words,independently featuresof one another during early processing and are “freenot floating”associated sowith a specific object, they maycan easily be incorrectly combined both in laboratory settings, as well as in real life situations.<ref>Treisman, A. Cognitive Psychology 12, 97-136 (1980)</ref>
Research participant R.M., a [[Bálint's syndrome]] sufferer who is unable to focus attention on individual objects, experiences illusory conjunctions when presented with simple stimuli such as a "blue O" or a "red T." For 23% of trials, even when able to view the stimulus for as long as 10 seconds, R.M. reported seeing a "red O" or a "blue T".<ref>Friedman-Hill et al., 1995; Robertson et al., 1997.</ref> This finding is in accordance with feature integration theory's prediction of how one with a lack of focused attention would erroneously combine features.
