AP Psychology Unit 2: Cognition Notes

Introduction

Cognition turns selected sensory input into organized perceptions, decisions, memories, and measurements whose strengths and limits can be tested.

This unit connects perception, thought, memory, and intelligence through one recurring idea: the mind does not copy information. It selects, organizes, stores, reconstructs, and evaluates information under limited attention and uncertainty.

For each process, separate performance from mechanism. A person’s response is observable; attention, memory trace, heuristic, or latent ability is an explanatory model. Strong evidence compares predictions and states what the design cannot establish.

Sensation + context

perception

Representations + strategies

judgment and problem solving

Encoding + storage + cues

retrieval

Defined construct + standardized evidence

test interpretation

Current exam guidance: Aligned to the current 2026–27 AP Psychology framework and its emphasis on concepts, research methods, data interpretation, and evidence-based argument.

2.1

Perception

How does the mind organize sensation into perceived objects and events?

Short answer

Bottom-up features interact with attention, expectation, context, and learned regularities to produce useful but fallible interpretations.

Know firstSensation and transduction · Neural pathways

Perception is a constrained interpretation

Bottom-up processing begins with stimulus features: edges, color, movement, pitch, or pressure. Top-down processing uses goals, expectations, knowledge, and context to organize those features. These streams operate together. An ambiguous shape may be interpreted differently in two contexts even though its geometry is unchanged, but top-down expectation cannot turn any input into any percept.

Gestalt principles describe regular ways elements are grouped, including proximity, similarity, continuity, closure, and figure–ground organization. Depth cues estimate spatial layout, while perceptual constancy supports stable judgments of size, shape, and color as viewing conditions change. These are efficient assumptions about the environment, not perfect reconstructions.

Selective attention prioritizes some input. Inattentional blindness is failure to notice an unexpected event when attention is elsewhere; change blindness is failure to detect a change across a disruption or competing scene. Neither means unattended information has no effect. Cultural experience and environments can change familiarity with particular cues, so one illusion does not justify a universal claim or a deficit label.

Gestalt diagram demonstrating proximity, similarity, continuity, closure, and figure-ground organization — The same elements can organize into different objects
Perception groups elements using regularities that usually help identify objects. Changing spacing or context can change the organization without changing each element.
Use this visual to see
Compare five grouping principles using the physical relations that trigger them.
What it cannot show
Five small panels show dots grouped by distance, shapes grouped by similarity, a continuous crossing path, an incomplete shape perceived through closure, and a reversible figure-ground silhouette.
Test Ninjas · Original educational diagram

Spotlight diagram showing attended information, unattended information, and an unexpected event outside the focus — Attention selects; it does not record everything
A demanding task concentrates processing on selected input. An unexpected event may remain unnoticed even when it is visible.
Use this visual to see
Distinguish limited conscious awareness from the stronger claim that unattended input has no effect.
What it cannot show
A bright attentional beam covers one task stream while other signals and an unexpected event remain outside it. The drawing represents allocation, not a literal beam in the brain.
Test Ninjas · Original educational diagram

Locate the source of a perceptual judgment

Process	Information emphasized	What it helps explain	Limit
bottom-up	current sensory features	detection and feature assembly	features still require organization
top-down	expectation and knowledge	context and perceptual set	cannot override all sensory constraints
Gestalt grouping	relations among elements	objects and figure–ground	describes organization more than a full neural mechanism
selective attention	task-relevant input	missed unexpected events	unattended processing is not always zero
constancy	stable object properties	recognition across changing views	can contribute to illusion

Explain a perceptual error

Describe the physical input without naming the interpretation.
Identify the grouping cue, depth cue, expectation, or attentional demand.
State the resulting percept.
Explain why the rule is normally useful.
Avoid claiming that one demonstration applies identically across people and settings.

Keep these three ideas

Bottom-up and top-down processing operate together.
Grouping and constancy create stable objects from changing input.
Attention limits awareness without necessarily eliminating all processing.

Cognition

Introduction

Perception

Perception is a constrained interpretation

The same elements can organize into different objects

Attention selects; it does not record everything

Locate the source of a perceptual judgment

Explain a perceptual error

Keep these three ideas

Keep reading Unit 2: Cognition

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