Editing Stroop effect (section)

== Experimental findings ==
Stimuli in Stroop paradigms can be divided into three groups: neutral, congruent and incongruent. Neutral stimuli are those stimuli in which only the text (similarly to stimuli 1 of Stroop's experiment), or color (similarly to stimuli 3 of Stroop's experiment) are displayed.<ref name="pmid19966248" /> Congruent stimuli are those in which the ink color and the word refer to the same color (for example the word "pink" written in pink). Incongruent stimuli are those in which ink color and word differ.<ref name="pmid19966248" /> Three experimental findings are recurrently found in Stroop experiments.<ref name="pmid19966248">{{cite journal |vauthors=van Maanen L, van Rijn H, Borst JP |title=Stroop and picture-word interference are two sides of the same coin |journal=Psychon Bull Rev |volume=16 |issue=6 |pages=987–99 |date=December 2009 |pmid=19966248 |doi=10.3758/PBR.16.6.987 |doi-access=free }}</ref> A first finding is ''semantic interference'', which states that naming the ink color of neutral stimuli (e.g. when the ink color and word do not interfere with each other) is faster than in incongruent conditions. It is called semantic interference since it is usually accepted that the relationship in meaning between ink color and word is at the root of the interference.<ref name="pmid19966248" /> The second finding, ''semantic facilitation'', explains the finding that naming the ink of congruent stimuli is faster (e.g. when the ink color and the word match) than when neutral stimuli are present (e.g. stimulus 3; when only a colored square is shown). The third finding is that both semantic interference and facilitation disappear when the task consists of reading the word instead of naming the ink color. It has been sometimes called ''Stroop asynchrony'', and has been explained by a reduced automatization when naming colors compared to reading words.<ref name="pmid19966248" />

In the study of [[interference theory]], the most commonly used procedure has been similar to Stroop's second experiment, in which subjects were tested on naming colors of incompatible words and of control patches.  The first experiment in Stroop's study (reading words in black versus incongruent colors) has been discussed less. In both cases, the interference score is expressed as the difference between the times needed to read each of the two types of cards.<ref name="pmid2034749" /> Instead of naming stimuli, subjects have also been asked to sort stimuli into categories.<ref name="pmid2034749" /> Different characteristics of the stimulus such as ink colors or direction of words have also been systematically varied.<ref name="pmid2034749" /> None of all these modifications eliminates the effect of interference.<ref name="pmid2034749" />