Another development in the mid twentieth century with a huge import for the development of cognitive psychology was the opening up of a new field concerned with the possibility of designing and then building computers. Building on earlier work that developed a formal, or mathematical approach to logical reasoning, Claude Shannon in 1938 showed how core aspects of reasoning could be implemented in simple electrical circuits. In the 1940s, McCulloch and Pitts showed how it was possible to model the behaviour of simple (and idealized) neurons in terms of logic. Taken together, these developments suggested something that at the time seemed extraordinary – that the brain’s activity could, at least in principle, be implemented by simple electrical circuits. In parallel with these developments, the 1930s and 1940s saw pioneering theoretical developments in computation and information processing. Turing, in 1936, developed an abstract specification for a machine (a Turing machine) that