This work would not be possible without help or indulgent attitude of a numerous group of people whose extent prevents me from listing all those to whom I direct my gratitude.

Without disinterested help from Dr Edward Gorzelanczyk (Medical Academy of Poznan), I would never come to revive my rusty background in molecular biology and attempt formulating molecular model of two components of long-term memory. It was also Dr Gorzelanczyks merit to patiently supervise the progress of students working with SuperMemo databases and collecting the data related to their learning process over the last three years

Janusz Murakowski (University of Delaware) was helpful in opening my eyes to mathematical inconsistencies in a number of models presented in my Masters Thesis and in the presented dissertation. Those included: model of intermittent learning, model of action potential in nerve cells, model of adrenergic synapse and model of two-components of long-term memory

Prof. Andrzej Baborski (University of Economics in Wroclaw) was instrumental in making it possible for me to present my research at the University of Economics in Wroclaw, and to open the formal process towards obtaining a doctoral degree

Krzysztof Biedalak and Marczello Georgiew (SuperMemo World) made my focused work on the presented dissertation possible by showing unheard-of patience and tolerance during long months of my persistent neglect of routine duties at SuperMemo World

Piotr Metzler (SuperMemo World) disinterestedly devoted a great deal of his personal time in order to help me focus entirely on my work in the last two months of writing this dissertation.

Prof. Zbigniew Kierzkowski (University of Technology in Poznan) opened my way to unconstrained research on memory and learning yet during my undergraduate student years through his support in breaking administrative barriers that made it difficult to branch into multidisciplinary subjects because of rigid university regulations in the mid 1980s

I would not have ever had an opportunity to continue my university studies and free-lance research without a continuous and unswerving support from my late mother and my late sister

Last, but by no means least, Prof. Witold Abramowicz (University of Economics in Poznan) should take no less than half the credit for the finalization of the presented dissertation. Over the last three years, Prof. Abramowicz provided me with comradely encouragement, fatherly guidance, and Socratic inspiration of highest intellectual quality. He also showed nearly evangelical patience in tolerating the stubborn me. To him finally goes the credit for the ultimate appearance of this dissertation in the presented form