Human cognition is the study of how the human brain thinks. As a science, human cognition seeks to be more than only theoretical in that its theories must lead to working models that demonstrate behavior similar to human thought. The extent to which these models can be measured as similar to, or indistinguishable from, human thought is the measure of the accuracy of the human cognition model. The terms cognitive modeling, and Artificial Intelligence (AI) are sometimes used as synonyms of human cognition. The AI study of natural language understanding is the the subfield of human cognition that seeks to model the way the human brain processes and understands spoken human languages, such as English speech. Picture of a human brain generated from MRI data Sagittal slice from a fMRI scan of a human brain. ... Natural Language Processing (NLP) is a subfield of artificial intelligence and linguistics. ...

Background and history

One could argue that human cognition began with the mathematical musings of the ancient world that attempted to mathematically codify logic. Modus ponens is a simple statement from that era that says, "If A implies B (written as: A → B) is known to be a true statement, and you also know that A is true, then you can conlcude that B is true." Successive application of the modus ponens principle can yield logical "reasonable" conclusions that may not be as apparent to the casual observer. For example, given the set of the following four statements: C → D, B → C, D → E, and A → B, and also given that you know that A is true, one can conclude that E is true. Is that as easily apparent as seeing that B is true? Modus ponens is the basis of the human cognition model that elicits the human-like deductive reasoning in modern rule-based expert systems. Logic (from ancient Greek λόγος (logos), originally meaning the word, or what is spoken, but coming to mean thought or reason) is most often said to be the study of arguments, although the exact definition of logic is a matter of controversy amongst philosophers (see below). ... Modus ponens (Latin: mode that affirms) is a valid, simple argument form (often abbreviated to MP): If P, then Q. P. Therefore, Q. or in logical operator notation: where represents the logical assertion. ...

The English mathematician, Alan Turing, gave us the Turing Theorem, which is the theoretical basis for John von Neumann's Von Neumann machine which, in turn, became the theoretical basis of the modern digital computer. The Turing Theorem is the statement and proof that shows that all problems that can be solved, can be solved by first building a theoretical state-space of all possible state transitions and then traversing this state space until the problem solution is found. Turing was personally interested in creating a machine that could reason like a human, and his theorem was a significant contribution toward that end. We now know that human brains are not very similar at all to modern digital computers, but Turing's and Von Neumann's work gave us the tools to get started in building computer models of human cognition. Alan Turing, often considered the father of modern computer science. ... John von Neumann in the 1940s. ... A von Neumann machine is a model created by John von Neumann for a computing machine that uses a single storage structure to hold both the set of instructions on how to perform the computation and the data required or generated by the computation. ... The tower of a personal computer (specifically a Power Mac G5). ...