Introduction to Cognitive Psychology: Foundations, History, and Models

Introduction to Cognitive Psychology

Definition and Scope

Cognitive psychology is the scientific study of mental processes, including how the mind controls perception, attention, memory, emotions, language, decision making, thinking, and reasoning. It investigates the processes by which sensory input is transformed, reduced, elaborated, stored, retrieved, and used (Neisser, 1976). Cognitive psychology is distinct from clinical, abnormal, and social psychology.

• Transformation: Sensory input is converted into mental representations.

• Reduction: Filtering out irrelevant sensory information to focus on what is important for the task.

• Elaboration: Adding information to sensory input to enhance understanding or performance.

• Storage and Retrieval: Information is encoded into memory and later accessed when needed. Storage does not guarantee retrieval.

Example: Phoning for pizza requires transforming the visual features of digits into finger movements on a phone keypad.

Additional info: Sensation is foundational to cognition; all knowledge originates from sensory experiences.

Historical Foundations of Cognitive Psychology

Early Thinkers and Experiments

• Aristotle (350 BC): Distinguished between memory retention (encoding information for later use) and recall (deliberate retrieval of information).

• Donders (1868): Conducted the first modern cognitive psychology experiment, measuring reaction time (RT) to infer mental processes involved in decision making.

Types of Reaction Time

• Simple RT: Press a button as soon as a stimulus appears (no decision required).

• Choice RT: Press one button for one stimulus and another button for a different stimulus (requires a decision).

Key Formula:

$\text{Decision Time} = \text{Choice RT} - \text{Simple RT}$

Choice RT is typically about 1/10th of a second longer than Simple RT, reflecting the time needed to make a decision.

Example: In a lab task, participants press 'J' when a light appears (Simple RT) or 'J' for left light and 'K' for right light (Choice RT).

Additional info: Mental operations are inferred from behavior, as they cannot be measured directly.

Ebbinghaus and the Study of Memory

• Hermann Ebbinghaus (1885): Pioneered experimental study of memory and forgetting using lists of nonsense syllables.

• Developed the method of savings to quantify memory retention:

$\text{Savings} = \frac{\text{Initial repetitions} - \text{Relearning repetitions}}{\text{Initial repetitions}}$

• Plotted percent savings as a function of time delay to create the forgetting function.

• Most forgetting occurs soon after learning; after about three days, forgetting slows significantly.

Introspection, Behaviorism, and the Cognitive Revolution

• Analytic Introspection (Wundt, 1879): Trained observers described their mental experiences in detail.

• Behaviorism (Watson, 1913; Skinner, 1938): Focused on observable behavior and external stimuli, rejecting the study of mental states. Introduced classical conditioning and operant conditioning (learning via reinforcement).

• Chomsky (1959): Critiqued behaviorist explanations of language, arguing that language acquisition is innate and not solely based on reinforcement or imitation.

These debates led to the decline of strict behaviorism and the rise of cognitive psychology, which recognizes the importance of internal mental processes.

Information Processing Model

Stages of Information Processing (Broadbent, 1958)

The information processing model likens the mind to a computer, describing how information flows through a series of stages:

• Sensory Memory: Briefly holds unprocessed sensory information (e.g., visual information for about 250 milliseconds).

• Attention: Selects relevant information for further processing, filtering out irrelevant data.

• Short-Term Memory (STM): Holds a limited amount of processed information (about 7 items) for 20–30 seconds.

• Long-Term Memory (LTM): Stores information permanently with unlimited capacity.

Example: When reading, sensory memory briefly holds the visual input, attention selects the relevant words, STM processes the sentence, and LTM stores the meaning for future use.

Additional info: The model emphasizes the transformation and flow of information, contrasting with behaviorism's stimulus-response approach, which does not specify internal processes.

Comparison: Information Processing vs. Behaviorism

Information Processing Model	Behaviorism (Stimulus-Response Model)
Specifies internal stages (sensory memory, attention, STM, LTM)	Focuses only on observable input and output
Emphasizes mental representations and transformations	Does not address internal mental states
Inspired by computer science	Inspired by animal learning experiments