The AP Psychology 5-hour live stream review is here! 🧠

Join us on May 10, 2021 for the 🌶️ AP Psychology Cram Finale for a last minute review to get all your questions answered!


All Subjects



AP Psych



Unit 3

3.4 Visual Perception

3 min readaugust 5, 2020

Dalia Savy

Top-Down Processing

As said before, gestalt principles allow you to be vulnerable to illusion. Top-down processing is involved in your brain falling for these illusions.
Two important points to note about optical illusions are:
  • Comparisons govern our perceptions
    • When we look at an image, we perceive objects with regard to their environment. We don’t look at the subject in isolation, we look at the image as a whole.
  • The way you perceive (monocular cues + binocular cues) size and distance cause illusions.


Image Courtesy of AP Psychology.

👁 Monocular Cues

To recall, the main monocular cues are:
  • Relative Height
    • We perceive objects that are higher to be farther away from us. In the image below, it looks like the house is farther away because of this monocular cue.

Image Courtesy of Micky and Marissa.

  • Relative Size
    • If two images are, in reality, the same size, we would perceive the one closest to us to be larger. For example, if you place one teddy bear close to the camera and another really far away from the camera, the one closer would look larger. This happens even though the two teddy bears are really the same size.
  • Interposition
    • If one image covers another, it looks closer/larger.

Image Courtesy of Sjsu.

  • Relative Motion/Motion Parallax
    • When we are in motion, the objects we are looking at look like they are moving, as well. You could see this happening when you're in a car looking out the window.
  • Linear Perspective
    • Parallel lines look like they come together in the distance.

Image Courtesy of @Psych_Review.

  • Light and Shadow
    • When there are shadows involved, there is a perception of depth.

Image Courtesy of Jim Foley

👀 Binocular Cues

The main binocular cue to know is retinal disparity, the difference between the two images your eyes see. Your brain judges distance by comparing the images from both eyes.

Practice AP Question

The following question is from the 2011 AP Psychology Exam. It's great review for both this unit and unit 1!
  1. A researcher designs a study to investigate the effect of feedback on perception of incomplete visual figures. Each participant stares at the center of a screen while the researcher briefly projects incomplete geometric figures one at a time at random positions on the screen. The participant’s task is to identify each incomplete figure. One group of participants receives feedback on the accuracy of their responses. A second group does not. The researcher compares the mean number of figures correctly identified by the two groups.
A. Identify the independent and dependent variables in the study.
B. Identify the role of each of the following psychological terms in the context of the research
  • Foveal Vision
  • Feature Detectors
  • Gestalt principle of closure
C. Describe how each of the following terms relates to the conclusions that can be drawn based on the research.
  • Random Assignment
  • Statistical Significance
👉Scoring Guidelines for this Question
🎥 Watch: AP Psychology - Visual Anatomy and Perception


Was this guide helpful?

💪🏽 Are you ready for the Psych exam?
Take this quiz for a progress check on what you’ve learned this year and get a personalized study plan to grab that 5!
FREE AP psych Survival Pack + Cram Chart PDF
Sign up now for instant access to 2 amazing downloads to help you get a 5
Browse Study Guides By Unit
Big Reviews: Finals & Exam Prep
Free Response Questions (FRQ)
Multiple Choice Questions (MCQ)
Unit 1: Scientific Foundations of Psychology
Unit 2: Biological Bases of Behavior
Unit 4: Learning
Unit 5: Cognitive Psychology
Unit 6: Developmental Psychology
Unit 7: Motivation, Emotion, & Personality
Unit 8: Clinical Psychology
Unit 9: Social Psychology
Join us on Discord
Thousands of students are studying with us for the AP Psychology exam.
join now
Play this on HyperTyper
Practice your typing skills while reading Visual Perception
Start Game