 Thus, colors lose their metric arrangement when they are colors of differently categorized objects (such as “apple” and “banana”) rather than colors of objects that do not belong to different categories (e.g., apertures or pigment patches).Chingis Izmailov also hypothesized, based on the evoked potential experiments, that the system responsible for detection of changes in brightness is physiologically different from the system responsible for detecting spatial patterns.In the later period of his life Chingis Izmailov was working on a comprehensive theory of perception as having a formal structure of a language, with levels analogous to those of graphemes/phonemes, letters, and words.