Vygotsky and Luria informally collaborated with other psychologists, educationalists, medical specialists, physiologists, and neuroscientists. The foundation of the integrative science of the mind, brain, and behavior in their bio-social development, was the main work of the Circle. They incorporated ideas of social and interpersonal relations, the practices of empirical scientific research, and "Stalinist science" founded on the discursive practices of Soviet science in the 1930s. There were around three dozen people involved in the research for Vygotsky's theory, at different periods of time.