Cognitive Psychology: Perception, Memory and Thought

Cognitive psychology is the scientific study of internal mental processes: perception, attention, memory, language, problem-solving, reasoning, and decision-making. It rose to dominance in the late 1950s, displacing strict behaviourism by treating the mind as an information-processing system.

The cognitive revolution

Three landmarks mark the shift:

1. George Miller's 1956 paper The Magical Number Seven, Plus or Minus Two — short-term memory holds about 7 ± 2 chunks of information.
2. Noam Chomsky's 1959 review of Skinner's Verbal Behavior — language cannot be explained by reinforcement alone, the mind must have innate structures.
3. Ulric Neisser's 1967 textbook Cognitive Psychology — formally named and consolidated the field.

The information-processing model — input → encoding → storage → retrieval → output — became the discipline's organising metaphor.

Perception and attention

Perception is the brain's interpretation of sensory input. Two contrasting accounts:

• Bottom-up (data-driven) processing — perception built from sensory elements; identified with J. J. Gibson's ecological theory of direct perception.
• Top-down (concept-driven) processing — perception shaped by expectations, context, and prior knowledge; identified with Richard Gregory.

Attention is the selective allocation of cognitive resources. Classic theories:

• Broadbent's filter model (1958) — a hard "early" filter selects one input.
• Treisman's attenuation model (1964) — unattended channels are dampened but not blocked.
• Deutsch & Deutsch late-selection model (1963) — all inputs reach semantic analysis; selection happens later.

The cocktail-party phenomenon — hearing your name across a noisy room — illustrates how unattended channels still receive some processing.

Memory

The Atkinson-Shiffrin multi-store model (1968) divides memory into three stores:

1. Sensory memory — large capacity, very brief (less than a second for iconic; up to 4 seconds for echoic).
2. Short-term / working memory — capacity ~7 ± 2 chunks, duration ~15–30 seconds.
3. Long-term memory — virtually unlimited capacity, very long duration.

Alan Baddeley revised STM into working memory with four components: central executive, phonological loop, visuospatial sketchpad, and episodic buffer.

Long-term memory subdivides into:

Type	Content	Example
Episodic	Personal events	Your last birthday
Semantic	General knowledge	The capital of Pakistan is Islamabad
Procedural	Motor skills	Riding a bicycle
Priming	Implicit influence of prior exposure	Faster recognition after a related cue

Language

Language is studied at several levels: phonology (sounds), morphology (word formation), syntax (sentence structure), semantics (meaning), and pragmatics (use in context). Chomsky's Language Acquisition Device posits an innate, species-specific capacity for grammar. Steven Pinker popularised the view of language as an evolved instinct.

Thinking, reasoning, and problem-solving

Problem-solving strategies include:

• Algorithm — guaranteed step-by-step method.
• Heuristic — quicker rule of thumb.
• Insight — sudden restructuring (Köhler's chimpanzees).
• Means-end analysis — reduce distance to goal at each step.

Kahneman & Tversky's heuristics-and-biases programme identified:

• Availability heuristic — judging frequency by ease of recall.
• Representativeness heuristic — judging by resemblance to a prototype.
• Anchoring and adjustment — being pulled toward an initial reference value.
• Confirmation bias — seeking information that supports existing beliefs.

These insights, captured in Kahneman's Thinking, Fast and Slow (2011), distinguished System 1 (fast, automatic, intuitive) from System 2 (slow, deliberate, analytical).

Intelligence

Charles Spearman (1904) proposed a general intelligence factor g. Louis Thurstone countered with seven primary mental abilities. Howard Gardner's multiple intelligences (1983) added eight or nine intelligences (linguistic, logical-mathematical, spatial, musical, bodily-kinaesthetic, interpersonal, intrapersonal, naturalist, existential). Robert Sternberg's triarchic theory distinguishes analytical, creative and practical intelligence.

IQ measurement

• Stanford-Binet — first widely used standardised IQ test (Terman, 1916).
• Wechsler scales — WAIS for adults, WISC for children, WPPSI for pre-schoolers; mean 100, SD 15.

Why cognition matters for policy

Cognitive insights now drive applied programmes — nudge units built around heuristics and biases inform tax compliance, vaccination uptake, and exam-design reform. The 2017 Nobel for Richard Thaler marked behavioural economics' formal recognition. In Pakistan, the State Bank and FBR have piloted behavioural-nudge interventions in tax filing and consumer protection.