Immanuel Kant once remarked, “The hand is the window on to the mind.” In this line of research, we study how humans learn complex motor skills, especially dexterous manual skills. This offers us an opportunity to peek into the workings of the human mind. We study healthy participants highly skilled movement in everyday life, such as typing, texting, cooking, as well as experts, such as athletes, musicians, surgeons, etc., by tracking people’s hand movements in more naturalistic contexts using advanced biomechanics devices and machine learning algorithms. Our previous research using experiments that mimics the Markov Chain Monte Carlo (MCMC) process in human information transmission has shown to be a powerful paradigm to probe high-dimensional psychological spaces in categorization and memory(2010,2013) . Here we employ this approach to study learning and memory of complex motor skills. Knowledge gained from this line of research will not only shed light on human intelligence but also inform how to effectively train novices to high-level of skill performance.