Editing Cognitive science (section)

===Levels of analysis===
{{See also|Functionalism (philosophy of mind)}}
A central tenet of cognitive science is that a complete understanding of the mind/brain cannot be attained by studying only a single level. An example would be the problem of remembering a phone number and recalling it later. One approach to understanding this process would be to study behavior through direct observation, or [[naturalistic observation]]. A person could be presented with a phone number and be asked to recall it after some delay of time; then the accuracy of the response could be measured. Another approach to measure cognitive ability would be to study the firings of individual [[neuron]]s while a person is trying to remember the phone number. Neither of these experiments on its own would fully explain how the process of remembering a phone number works. Even if the technology to map out every neuron in the brain in real-time were available and it were known when each neuron fired it would still be impossible to know how a particular firing of neurons translates into the observed behavior. Thus an understanding of how these two levels relate to each other is imperative. [[Francisco Varela]], in ''The Embodied Mind: Cognitive Science and Human Experience'', argues that "the new sciences of the mind need to enlarge their horizon to encompass both lived human experience and the possibilities for transformation inherent in human experience".<ref>Varela, F. J., Thompson, E., & Rosch, E. (1991). The embodied mind: cognitive science and human experience. Cambridge, Massachusetts: MIT Press.</ref> On the classic cognitivist view, this can be provided by a functional level account of the process. Studying a particular phenomenon from multiple levels creates a better understanding of the processes that occur in the brain to give rise to a particular behavior.
[[David Marr (psychologist)|Marr]]<ref>Marr, D. (1982). ''Vision: A Computational Investigation into the Human Representation and Processing of Visual Information''. W. H. Freeman.</ref> gave a famous description of three levels of analysis:

# The ''computational theory'', specifying the goals of the computation;
# ''Representation and algorithms'', giving a representation of the inputs and outputs and the algorithms which transform one into the other; and
# The ''hardware implementation'', or how algorithm and representation may be physically realized.