Activity theory
Activity theory (AT; ) is an umbrella term for a line of eclectic social sciences theories and research with its roots in the Soviet psychological activity theory pioneered by Lev Vygotsky , Alexei Leont'ev and Sergei Rubinstein. These scholars sought to understand human activities as systemic and socially situated phenomena and to go beyond paradigms of reflexology (the teaching of Vladimir Bekhterev and his followers) and classical conditioning (the teaching of Ivan Pavlov and his school), psychoanalysis and behaviorism. It became one of the major psychological approaches in the former USSR, being widely used in both theoretical and applied psychology, and in education, professional training, ergonomics, social psychology and work psychology.
Associationism
The idea is first recorded in Plato and Aristotle, especially with regard to the succession of memories. Members of the principally British ""Associationist School"", including John Locke, David Hume, David Hartley, Joseph Priestley, James Mill, John Stuart Mill, Alexander Bain, and Ivan Pavlov, asserted that the principle applied to all or most mental processes. Particularly, Locke's view that the mind and body are two aspects of the same unified phenomenon can be traced back to Aristotle's ideas on the subject. Later members of the school developed very specific principles elaborating how associations worked and even a physiological mechanism bearing no resemblance to modern neurophysiology. For a fuller explanation of the intellectual history of associationism and the "Associationist School", see "Association of Ideas".