The book contains the proceedings of The Warsaw Colloquium on Instrumental Conditioning and Brain Research held in Jablonna near Warsaw on May 1-5, 1979. The proceedings are also published in the sixth issue of 1979 and the first issue of 1980 of Acta Neurobiologiae Experimentalis. Three papers published later, in the fourth issue of 1980, are also included. The aim of this Symposium was to honour the memory of the great Polish neurophysiologist Jerzy Konorski and the sixtieth anniversary of the Nencki Institute, where Professor Konorski has created his school. Forty-five papers, prepared mainly by Konorski's pupils and scientific friends, cover several fields of current brain research. To each of them Professor Konorski contributed significantly. In fact, many presented papers have been strongly influenced by his scientific ideas. Perhaps the most conspicuous feature of the Symposium was its very international character due to numerous participants from both East and West. As such, the Symposium is a worthy symbol of the aehievements of both Jerzy Konorski himself and the Neneki Institute as a whole in the field of cooperation of scientists from East and West. Scientific sessions were held in the mornings and afternoons. In the evenings the participants mutually read and commented their papers. Moreover, colleagues from the USA and Great Britain eorrected the English of the manuscripts. In partieular Prof. J. F. Brennan, Prof.