Friday, August 14, 2015
Are lines always a means to more complex forms? Aleksander Rodchenko would not agree
Orientation selective cells of the visual cortex, which respond to lines of specific orientation, were discovered in 1959. They were first encountered in the primary visual cortex of the brain (area V1) – considered by many for much too long to be the only entering place of visual information into the rest of the visual brain. Such cells have usually been thought of as the initial staging post for the elaboration of more complex forms. Some, indeed most, believe that they are the sole source for the elaboration of more complex forms such as faces, houses and objects. I am becoming increasingly skeptical of this view.
First of all, evidence which is largely ignored or at least marginalized, although it has been available since 1980, shows that V1 is not the only entering place of visual signals into other areas of the visual brain; there are alternative routes which reach them without passing through V1. Secondly, orientation selective cells are found in at least four other visual areas of the visual brain, and these cells survive functionally even when deprived of an input from V1 (i.e. they remain orientation selective cells); they are, very likely, fed by these alternative inputs. Thirdly, visual signals related to form (oriented lines) reach V1 and the other visual areas within the same time frame. And, finally, clinical evidence shows that humans can become agnosic (blind) for line drawings without at the same time becoming agnosic for real objects.
Hence, one must seek for sources besides V1 for elaborating orientation selective cells and complex forms, which is not to say that V1 cells do not contribute significantly to this process. But perhaps one should also consider, at the same time, that oriented lines stand on their own as forms in every sense, without their being mere “building blocks” for elaborating more complex forms.
Neurobiologists are not alone in considering oriented lines a means towards a more complex end. Mondrian, among others, sought for the constant elements in all forms and settled on the straight lines, provided they are vertical and horizontal. He abhorred diagonal lines, breaking off his working relationship with a colleague because “of the high handed way in which you have treated the diagonal line”. Ever the reductionist (though not accused of it, as we commonly are), he believed that “there are also constant truths concerning forms” and it was the function of the artist “to reduce natural forms to the constant elements”.
Many others, including Kazimir Malevich, Ellsworth Kelly and Barnet Newman, among others, have emphasized lines in some of their paintings, for different reasons. But it was perhaps Aleksander Rodchenko, the Russian Constructivist artist, who was most explicit in giving the straight line its autonomy. Influenced by Malevich and Suprematism, he wrote: “ I introduced and proclaimed the line as an element of construction and as an independent form in painting”. In another context, he also wrote "I reduced painting to its logical conclusion” (although he, too, was not (as far as I know) accused of reductionism). There are, incidentally, very good perceptual reasons for why he should not have been accused of reductionism, but I will leave that to a future post.
The point of all this is simple: that lines are not only a means towards something more complex; they can also stand on their own as a form or forms; that, as the Gestalt psychologists emphasized, “the whole is other than the sum of the parts” and that a complex form, even when constituted from lines, is one that is other than a combination of lines – an important lesson in the physiology of forms; and that there is much more to the construction of forms in and by the brain than a single source which lies in the orientation selective cells of V1.
It seems to me that the physiology of form construction by the brain is still, in spite of all the excellent work that has been done in the field, a field that is rich for exploration but also requires some of the facts mentioned above to be taken into consideration. In that exploration perhaps the products of artists should also play some role, even if only a minor one.
© Semir Zeki