The Human Information Processing System

Levels of Analysis

Different ways cognitive phenomena can be studied, typically divided into computational, algorithmic, and implementational levels.

Computational Theory

The highest level of analysis focusing on what a cognitive system does and why it does it.

Representation and Algorithm

The middle level of analysis concerned with how information is represented and manipulated to perform a cognitive function.

Implementation

The lowest level of analysis addressing how cognitive processes are physically realized in the brain.

Cognitive Psychology

The study of mental processes such as perception, memory, and problem-solving.

Cognitive Neuroscience

The study of the neural mechanisms underlying cognitive processes.

Mental Representation

Internal symbols or structures that stand for external objects, concepts, or events.

Cognitive Process

Any mental activity that processes information, such as attention, memory, or decision-making.

Local Representation

A representation where one unit is assigned to one concept.

Distributed Representation

A representation that encodes concepts across multiple units.

Automatic Processing

Processes that require little attention and occur unconsciously.

Controlled Processing

Processes that require conscious effort and attention.

Sequential Processing

Processing that handles one task at a time.

Parallel Processing

Processing that handles multiple tasks simultaneously.

Cascaded Processing

A mixture of sequential and parallel processing where later stages begin before earlier stages are fully completed.

Bottom-Up Processing

Processing driven by external stimuli.

Top-Down Processing

Processing guided by prior knowledge.

Interactive Processing

Processing that combines both bottom-up and top-down approaches.

Symbolic Processing

Processing involving discrete, rule-based representations.

Subsymbolic Processing

Processing involving continuous, distributed patterns.

Modularity Hypothesis

The idea that the mind consists of specialized, independent modules that process information separately.

Short-Term Memory

A limited-capacity memory store that holds information temporarily.

Long-Term Memory

A memory store with theoretically unlimited capacity that holds information for extended periods.

Procedural Memory

A type of long-term memory responsible for knowing how to perform tasks.

Declarative Memory

A type of long-term memory responsible for facts and events.

Episodic Memory

A subtype of declarative memory involving personal experiences and events.

Semantic Memory

A subtype of declarative memory involving general world knowledge and facts.

David Marr’s Three Levels of Analysis

The levels are computational, algorithmic, and implementational, addressing what a system does, how it does it, and how it is realized in the brain.

Questions for Computational Theory

1. What is the goal of the computation?

2. Why is this computation necessary?

Questions for Representation and Algorithm Theory

1. What representations are used?

2. What processes manipulate these representations?

Implementation Level Theory

It explains how the representations and processes are physically realized in the brain, such as through neural mechanisms.

Cognitive Psychology & Cognitive Science Focus

Primarily concerned with the computational and algorithmic levels of analysis.

Cognitive Neuroscience Focus

Primarily concerned with the implementational level of analysis.

Levels of Representation in Language

Phonological, lexical, syntactic, and semantic levels are involved in language comprehension and production.

Local vs. Distributed Representations

Local: One unit represents one concept. Distributed: A concept is represented by patterns across multiple units.

Cognitive Processes

They manipulate information to enable perception, memory, reasoning, and decision-making.

Controlled vs. Automatic Processing

Controlled processes require effort and attention; automatic processes occur without conscious effort.

Sequential vs. Parallel Processing

Sequential processing occurs step by step; parallel processing handles multiple streams simultaneously.

Cascaded Processing

A blending of sequential and parallel processing where later stages begin before earlier stages are completed.

Bottom-Up, Top-Down, Interactive Processing

Bottom-Up: Stimulus-driven; Top-Down: Expectation-driven; Interactive: Combination of both.

Symbolic vs. Sub-symbolic Processing

Symbolic: Rule-based with discrete symbols; Sub-symbolic: Continuous, distributed patterns (e.g., neural networks).

Modularity Hypothesis

The idea that the mind consists of specialized, independent modules that process information separately.

Properties of Modular Systems

Domain specificity, informational encapsulation, mandatory operation, and fast processing.

Procedural vs. Declarative Memory

Procedural: Knowing how (skills); Declarative: Knowing what (facts and events).

Types of Declarative Memory

Episodic memory (personal experiences) and Semantic memory (general knowledge).

Episodic vs. Semantic Memory

Episodic: Linked to personal experiences; Semantic: General knowledge not tied to personal experience.

Short-Term vs. Long-Term Memory

Short-term memory has limited capacity and duration; Long-term memory has vast capacity and lasts much longer.