Gunnar Svaetichin studied the biological effects of this faculty in fish and developed the S-potential to quantify this faculty.
Gunnar Svaetichin studied the biological effects of this faculty in fish and developed the S-potential to quantify this faculty. This faculty's interference of reaction time is the subject of the Stroop effect. One theory of this faculty that was expanded to quantify emotion by Richard Solomon includes three pairs of receptors for this faculty; that theory is the opponent-process theory. The most common form of synesthesia involves the perception of this faculty when viewing numbers and letters. Ishihara plates are used to diagnose this faculty's namesake blindness. For 10 points, identify this human faculty which is described by the trichromatic theory. 
Gunnar Svaetichin studied the biological effects of this faculty in fish and developed the S-potential to quantify this faculty.
color recognition/vision [prompt on vision or equivalents]