Human-computer interaction (HCI) applies cognitive psychology to the design, evaluation, and implementation of interactive computing systems. The field emerged from the recognition that technology should be designed to fit human cognitive capabilities rather than forcing humans to adapt to technology. Core cognitive principles — limited attention, working memory constraints, perceptual organization, mental models, and automaticity — are central to creating usable, efficient, and satisfying interfaces.
Key Structures
- Prefrontal cortex (task management) — The anterior portion of the frontal lobe, critical for executive functions including planning, decision-making, working memory, and cognitive control.
- Visual cortex (display processing) — The regions of the occipital lobe dedicated to processing visual information through a hierarchy of increasingly complex feature representations, particularly in relation to display processing.
- Motor cortex (input control) — The precentral cortical region that plans, initiates, and executes voluntary movements through corticospinal projections, particularly in relation to input control.
- Parietal cortex (spatial interaction) — The cortical region between frontal and occipital lobes, integrating sensory information for spatial representation and attention, particularly in relation to spatial interaction.
- Heuristics — Mental shortcuts or rules of thumb that simplify complex judgments and decisions, enabling fast and often adequate solutions at the cost of systematic errors and biases.
- Mental Models — Internal representations of external reality that people use to reason, predict, and explain — structuring understanding of how things work in the world.
- Recognition — A form of memory retrieval in which a previously encountered item is identified as familiar when presented again, typically easier than recall because the target item itself serves as a retrieval cue.
- Problem Solving — The cognitive processes involved in finding solutions to novel, non-routine challenges — from well-defined puzzles to ill-defined real-world problems.
- Ergonomics — The science of designing systems, products, and environments to fit human physical and cognitive capabilities — optimizing performance, safety, and well-being.
- Working Memory — A limited-capacity system for temporarily holding and manipulating information during complex cognitive tasks such as reasoning, comprehension, and learning.
- Eye — The sensory organ for vision, whose optical components focus light onto the retina for neural transduction.
- Gestalt Principles — The organizational rules by which the visual system groups elements into coherent wholes — proximity, similarity, closure, continuity, common fate, and figure-ground segregation.
- Recall — A form of memory retrieval in which previously learned information must be produced from memory without the item being physically present as a cue.
Key Functions
Studies how humans interact with computer systems, applying cognitive principles of attention, memory, and mental models to design effective user interfaces.
Cognitive Foundations
Fitts's law predicts movement time to targets based on distance and size, informing button and menu design. Hick's law relates choice reaction time to the number of alternatives, guiding menu structure. Miller's 7±2 (or Cowan's 4±1) limits on working memory capacity inform information chunking and progressive disclosure. Gestalt principles of perceptual organization (proximity, similarity, common fate) guide visual layout. Norman's concept of affordances — perceived action possibilities — guides control design. Mental models — users' internal representations of how systems work — determine how intuitive an interface feels.
Jakob Nielsen's 10 usability heuristics synthesize cognitive principles into practical design guidelines: visibility of system status, match between system and real world, user control and freedom, consistency and standards, error prevention, recognition rather than recall, flexibility and efficiency, aesthetic and minimalist design, error recovery, and help and documentation. Each heuristic maps onto cognitive psychology principles about perception, memory, attention, and problem solving.
Modern HCI
Contemporary HCI addresses mobile interfaces, voice interaction, gesture-based systems, virtual and augmented reality, and AI-powered adaptive interfaces. Cognitive load remains a central concern as interfaces become more complex. Eye tracking, think-aloud protocols, and cognitive walkthroughs are used to evaluate interfaces. The growing field of neuro-ergonomics uses brain imaging to measure cognitive load during interface use in real time.
Disorders
- Technostress — Stress and negative psychological states arising from the use of information and communication technologies in the workplace.
- Computer anxiety — Apprehension or fear related to computer use that impairs performance and technology adoption.
- Internet addiction — Excessive, compulsive internet use associated with tolerance, withdrawal, and functional impairment, sharing neural substrates with substance addiction.
- Information overload — A state in which the volume of available information exceeds processing capacity, impairing decision making and comprehension.