The turning point in the activity of the Slovenian OHO group was in the sense that their earlier thinking and creation still formed part of the European conceptualism, i. e. of art: now, however, they gradually left the field of art and were only partly linked with it. They turned to mysticism and transcendental meditation, in which the only functional means of information are telepathy and supersensory perception and energies. This change should not, however, be interpreted as an abandoning of the group's basic principles or the adoption of a private mythology. OHO still operated as a coherent group, but the individual development of each member, his perception of time and space, history and intellect became the source and structure of their conceptualism. The tendency towards the mental and the spiritual, which presupposes a thorough knowledge of the real material world, became the starting point of their activity. Though they did not become religious, their attention was drawn to all the phenomena in the area of spiritual production and its history. Marko Pogacnik, who was looking for a foothold in the intellectual tradition of Europe, found it in Empedocles and the Celts, in the study of the ethical tradition of European art history; Matanovic and Nez added to this and interest in Indian philosophy, Tarot and contemporary experimental music.

Seen from outside, this looks like a return to themselves: as a group they became composed and silent. Their life together and their mediations gained in intensity and further developed an indestructible link between them as well as true spiritual work which grew out of friendship and evolved into an emotional, intellectual and experiential whole. The OHO man, as explained by Marko Pogacnik was not an invention — he could be noticed and experienced at their shows in their work and in conversations with the artists themselves.

It all began in the early winter of 1970, when Matanovic and Nez went to New York to prepare the ground for the “Information Show”, a large-scale exhibition of conceptual art. Kynaston McShine had invited them through Taja Vidmar, to the exhibition which was planned for July, and their work throughout the preceding winter and spring was geared to it. While apart, they each recorded their mutual links during the separation in space and time. In the period between the 4th and the 28th February 1970, David Nez and Milenko Matanovic in New York and Andraz Salamun and Marko Pogacnik in Ljubljana simultaneously chose one of the combinations in a square, which had been prepared previously by Marko Pogacnik. In accordance with Milenko Matanovic's idea, all four of them looked toward the sun at the convened moment, dropped a match from a height of 10 cm onto a piece of paper and marked its position.

These simple exercises strengthened their mutual links, their awareness of the smallest shift of one towards the others and helped them develop the power of concentration and intuition in their relations, so that they could later communicate with each other regardless of the distance or time that separated them. This communion, which was based on the preceding expansion of individual actions, became their main task. But the plunge into the spiritual sphere of interrelationships, the search for a foothold in the knowledge of one another, suddenly acquired a broader spiritual context, the registration of which are the projects in the Zarica Valley near Kranj. The valley hides a rich and stable spiritual tradition: neolithic settlements, Celtic burial mounds, a Slavonic burial ground, a medieval Gothic church, and, as the last layer of recollection located in this almost sacred area of nature, the OHO projects.

In them the artists used sun and light, night and fire, ritual movements, stones and water — all closely connected with the entire spiritual energy. Their theme is spiritual communication with the past, the cosmos, the rhythm of nature, the beats of their own hearts and thoughts. At that time they also conceived their night projects of linking the sky and the earth, which, even if recorded only in the way that Matanovic's projects have been described here, paved the way for the transcendental level of their existence.

The year 1970 brought them success at the “Information Show” in New York and further exhibitions abroad and at home, where they took part at the Fourth Belgrade Triennale. When Walter de Maria came on a short visit in the summer, they produced with him a friendly project; however, they devoted most of their time to joint meditations (in the village of Cezsoca in Trenta) and to life together. It was there that they made the decision which turned out to be the only right solution: as a result of their spiritual experiences they were no longer interested in exhibiting their increasingly intimate and metaphysical concepts and messages but in the everyday realization of these experiences, and this was possible only in nature, in close contact with it, in work and meditation which was taking them away from artistic life. In the spring of 1971 they found an abandoned farm-house at Sempas in the Vipava valley and moved into it. After that, they dispersed. Though only Marko's family stayed at Sempas, the spiritual and emotional community of the OHO group never ceased to exist.

Why did the OHO group stop exhibition in 1970, at the time when they earned recognition for the first time, when the way to the European conceptualist scene was open and when they were perhaps on the threshold of their greatest success? Simply because they were honest, because their creativity was always linked with their life, because the identity of conceptualism (in art) and their most personal decisions waere always consistent and complete, because they never belonged to the "art system" dictated by the art market and exhibition policies in the late sixties. When they felt the call to turn to a different kind of work, they did it unhesitatingly and immediately.

Excerpt from Tomaz Brejc, “OHO as an Artistic Phenomenon 1966—1971”, The New Art Practice in Yugoslavia 1966-1978, Gallery of Contemporary Art, Zagreb, 1978

[OHO is a portmanteau form coined from the Slovenian words oko (eye) and uho (ear). Applied to the field of perception it means the universal grasping of phenomena in their immediate presence, i.e. before the experience of perception becomes the basis of a different, specifically structured classification. OHO group initial members were Marko Pogacnik, Milenko Matanovic, Nasko Kriznar and Andraz Salamun. They worked as a group beginning in 1966 and were one of the first conceptual artists in the former Yugoslavia.]