Definition
Cognitive psychology is the sub-discipline of psychology that studies the internal mental processes by which information is perceived, attended to, encoded, stored, retrieved, manipulated, and used to guide action. Its central metaphor — the mind as an information-processing system, often loosely modelled on a computer — emerged in the 1950s and 1960s as a deliberate response to the limits of behaviourism, which had banned discussion of internal states from scientific psychology.
The field studies attention, perception, memory, language, problem-solving, decision-making, and the executive functions that coordinate them. Methods include behavioural experiments measuring response time and accuracy, neuropsychological case studies of patients with selective deficits, and increasingly, neuroimaging to localise the brain systems that implement each function.
Why it matters
How it works
The classic models decompose cognition into stages and stores. Information enters through sensory registers, is selected by attention, processed in working memory, and either encoded into long-term memory or lost. Working memory is severely limited — roughly four chunks of information held actively at once — which constrains everything from reading comprehension to mental arithmetic. Long-term memory is divided into declarative (facts and events) and procedural (skills) systems, with separate neural substrates.
Modern cognitive psychology has shifted from purely symbolic models toward hybrid accounts that incorporate parallel distributed processing, embodied cognition, and predictive coding — the idea that the brain is constantly generating expectations and processing the mismatch between prediction and input. Across all these frameworks the basic project remains: build computational models of mental processes that make testable predictions about reaction times, error patterns, and brain activity.