Cognition (lat. “to know”) is the term for the mental process, roughly akin to “thinking”.
The human thought process has many components, some of which are as follows:
Attention = alertness and awareness of incoming stimuli
Memory = ability to recall
Language = ability to produce and understand language
Problem solving = ability to deal with life as it is encountered
Decision making = ability to chose a plan of action
Perception = ability to correctly recognize stimuli, e.g. recognize a face
Information processing = ability to assemble and understand incoming information
Simple cognition is defined as the most basic form of thinking, such as being aware of a noise and responding to it. An example would be the startle response on an infant to a loud noise.
Complex cognition involves problem solving or decision-making requiring retrieval of earlier learned knowledge, and application of reasoning and judgment. Examples of complex cognition would be the ability to solve a mathematical problem or find an address on a roadmap.
Natural cognition is defined as any form of thought process that appears to develop at an early stage without instruction. An example of natural cognition is teaching. Children will teach each other about the environment and expected behavior without being instructed to do so.
Cognition impairment (deficit) has several forms:
Global deficit of intellectual performance, i.e. mental retardation
Specific deficit such as learning disorders and dyslexia
Drug-induced deficits, e.g. alcoholic intoxication
Neurologic disorder, e.g. Alzheimer’s disease
Note: Cognitive deficit due to neurologic disorder is called dementia.