What is cognition?

People often talk about “cognition” as if it means “conscious thinking”. But that’s not how the term is used in cognitive psychology. Here’s a little collection of quotations by folk attempting to define the concept:

1. Williamson (2006):

“Cognition is usually defined as something like the process of acquiring, retaining and applying knowledge. To a first approximation, therefore, cognitive science is the science of knowing. Knowing is a relation between the knower and the known. Typically, although not always, what is known involves the environment external to the knower. Thus knowing typically involves a relation between the agent and the external environment. It is not internal to the agent, for the internal may be the same whether or not it is related to the external in a way that constitutes knowing.”

2. LeDoux (1995)

“If cognition is defined broadly to include sensory information processing, such as that occurring in the sensory thalamus and/or sensory cortex, as well as the processing that occurs in complex association areas of cortex in the frontal lobes or hippocampus, then emotional processing by the amygdala is highly dependent on cognitive processing. If cognitive processing is defined narrowly to include only the higher mental functions most likely mediated by complex association cortex, then emotion is not necessarily dependent on prior cognitive processing.”

3. Clark and Grush (1999):

“Is not the notion of a truly cognitive agent, at root, the notion of something like a reflective agent? What is needed, we believe, is just a principled way to make this idea (of a reflective agent) precise and to purge it of its original (but probably superficial) associations with episodes of conscious reflection. […] Cognizers, on our account, must display the capacity for environmentally decoupled thought and the contemplation of options. The cognizer is thus the being who can think or reason about its world without directly engaging those aspects of the world that its thoughts concern.”

4. Neisser (1967):

“… the term “cognition” refers to all processes by which the sensory input is transformed, reduced, elaborated, stored, recovered, and used. It is concerned with these processes even when they operate in the absence of relevant stimulation, as in images and hallucinations… Given such a sweeping definition, it is apparent that cognition is involved in everything a human being might possibly do; that every psychological phenomenon is a cognitive phenomenon. But although cognitive psychology is concerned with all human activity rather than some fraction of it, the concern is from a particular point of view. Other viewpoints are equally legitimate and necessary.”


Clark, A., & Grush, R. (1999). Towards a cognitive robotics. Adaptive Behavior, 7 (1), 5-16.

LeDoux, J. E. (1995). Emotion: Clues from the brain. Annual Reviews of Psychology, 46, 209-235.

Neisser, U. (1967). Cognitive psychology. Meredith Publishing Company.

Williamson, T. (2006). Can cognition be factorized into internal and external components? In R. J. Stainton (Ed.), Contemporary debates in cognitive science. Malden MA: Blackwell Publishing.