This book did not arise from the needs of the intellect. Rather, it is the fulfillment of a desire that arose in our hearts. The goal is to honor Professor Jan Matysiak, our Boss, our Teacher, and, most importantly, our Friend. In the mid-1970s, Professor Matysiak created with his bare hands (literally clearing out a basement full of rubble) a rat lab in the Faculty of Psychology at the University of Warsaw. The lab at first was part of the Department of Psychology of Individual Differences, but in 1999 it became an independent experimental unit of the Department of Biological Psychology, and Professor Matysiak was appointed Head. (fragment) 2009 r.