Core Concepts and Processes
Cognitive psychology studies how the mind handles information, from the moment something hits your senses to the moment you act on it. The core processes covered here (perception, attention, memory, and decision-making) don't work in isolation. They constantly interact, and understanding how they fit together is the foundation for everything else in this course.
Three big ideas tie these processes together: mental representations (how the mind models the world internally), information processing stages (the sequence from sensory input to behavioral output), and executive functions (the control systems that keep everything coordinated).
Core Cognitive Processes and Information Processing
Core cognitive processes
Perception interprets raw sensory input and turns it into something meaningful. It relies on two complementary pathways:
- Bottom-up processing is data-driven. Your brain builds a percept from the raw stimulus features (edges, colors, sounds) without relying on prior knowledge.
- Top-down processing is knowledge-driven. Your expectations and past experience shape what you perceive. This is why you can read a sentence with misspelled words, or why visual illusions trick you: your brain "fills in" based on what it expects.
Attention filters the flood of sensory information so you can focus on what matters. Three major types show up throughout the course:
- Selective attention lets you focus on one source while ignoring others. The classic example is the cocktail party effect: you can follow a single conversation in a noisy room, yet still notice if someone across the room says your name.
- Divided attention is what happens when you try to handle multiple tasks at once. True multitasking is harder than most people think, because attention has limited capacity.
- Sustained attention (vigilance) is the ability to maintain focus over long periods, like a security guard monitoring camera feeds for hours.
Memory involves three stages: encoding information, storing it, and retrieving it later. Two systems are especially important at this level:
- Working memory holds and manipulates a small amount of information for short periods. Repeating a phone number long enough to dial it is a straightforward example.
- Long-term memory stores information over extended periods, from facts you studied last week to childhood experiences.
Decision-making draws on problem-solving, reasoning, and judgment to select a course of action. It ranges from quick, everyday choices to complex deliberations like career planning or financial decisions. As you'll see later in the course, decision-making is heavily influenced by mental shortcuts (heuristics) that can lead to systematic biases.
Mental representations in cognition
A mental representation is an internal model of something in the external world. Your brain doesn't store a literal copy of reality; it builds structured representations that organize knowledge and guide behavior.
The main types include:
- Propositions: language-like, abstract representations of meaning (e.g., "dogs are mammals")
- Mental images: visual or spatial representations you can inspect and manipulate in your mind
- Concepts: categories that group similar things together (e.g., "furniture," "justice")
- Schemas: organized knowledge structures that set expectations for familiar situations, like knowing the typical sequence of events at a restaurant
These representations do real cognitive work. Mental maps help you navigate a campus. Mental rotation lets you figure out whether a puzzle piece fits before you try it. Social scripts guide how you behave in a job interview versus at a party. They also shape perception (your expectations influence what you see), memory (associative networks link related concepts, making some memories easier to retrieve), and decision-making (schemas and heuristics can speed up choices but also introduce bias).
Stages of information processing
The information processing model treats the mind as a system that takes in data, transforms it through a series of stages, and produces output. The computer analogy isn't perfect, but it provides a useful framework.
The stages progress roughly as follows:
- Sensory input — Stimuli from the environment are detected by sensory organs.
- Perception — The brain interprets those stimuli, assigning meaning to patterns of light, sound, etc.
- Attention — Relevant information is selected for further processing; irrelevant information is filtered out.
- Working memory — Selected information is held and actively manipulated (e.g., comparing two options).
- Long-term memory — Information is encoded for storage or retrieved from existing stores.
- Response generation — A behavioral output is produced: an action, a verbal response, a decision.
Two modes of processing operate across these stages:
- Parallel processing handles multiple streams of information at the same time. When you look at a visual scene, your brain simultaneously processes color, shape, motion, and depth.
- Serial processing handles information one step at a time, which is typical for tasks that require deliberate, sequential reasoning (like solving a math problem step by step).
The system has real constraints. Cognitive load refers to the total mental effort being used at any given moment. When load is high, performance drops. Processing bottlenecks occur at stages where capacity is limited, particularly at the attention stage, which is why you struggle to follow two conversations at once.
Executive functions for cognitive control
Executive functions are higher-order cognitive processes that manage and coordinate goal-directed behavior. Think of them as the brain's management system: they don't do the work themselves, but they decide what gets done, in what order, and when to change course.
Three key components form the core of executive function:
- Inhibition — The ability to suppress irrelevant stimuli or prepotent responses. The Stroop task is the classic demonstration: when the word "RED" is printed in blue ink, you have to inhibit the automatic tendency to read the word in order to name the ink color.
- Working memory — Beyond simple storage, this involves actively manipulating information. Doing mental arithmetic (e.g., without paper) requires you to hold intermediate results while computing the next step.
- Cognitive flexibility — The ability to shift strategies or perspectives when demands change. The Wisconsin Card Sorting Test measures this by requiring you to figure out a new sorting rule after the old one stops working, without being told what changed.
These three components work together to support self-regulation, planning, and task switching. Managing a group project, for instance, requires you to inhibit distractions, hold the project plan in working memory, and flexibly shift between subtasks.
Executive functions also interact heavily with the other core processes. They direct attention (deciding what to focus on), coordinate memory systems (deciding what information to retrieve or update), and structure decision-making (planning steps and evaluating outcomes). Deficits in executive function show up across many areas of daily life, from academic performance to social interactions, which is why they're a major topic in both cognitive and clinical psychology.