Visual Perception and the Brain

This course is offered through Coursera — you can add it to your Accredible profile to organize your learning, find others learning the same thing and to showcase evidence of your learning on your CV with Accredible's export features.

Course Date: 08 September 2014 to 03 November 2014 (8 weeks)

Price: free

Course Summary

The course will consider how what we see is generated by the visual system, and what visual perception indicates about how the brain works. The evidence will be drawn from neuroscience, psychology, science history and philosophy. Although the discussions will be informed by visual system anatomy and physiology, the focus is on perception.

Estimated Workload: 3-4 hours/week

Course Instructors

Dale Purves

Dale Purves is Geller Professor of Neurobiology in the Duke Institute for Brain Sciences, with additional appointments in the department of Psychology and Brain Sciences, and the department of Philosophy at Duke University. He earned a B.A. from Yale University in 1960 and an M.D. from Harvard Medical School in 1964. After further clinical training at the Massachusetts General Hospital, service as a Peace Corps physician, and postdoctoral training at Harvard and University College London, he was appointed to the faculty at Washington University School of Medicine in 1973. He came to Duke in 1990 as the founding chair of the Department of Neurobiology at Duke Medical Center, and was subsequently Director of Duke's Center for Cognitive Neuroscience (2003-2009) and also served as the Director of the Neuroscience and Behavioral Disorders Program at the Duke-NUS Graduate Medical School in Singapore (2009-2013). Although Purves was elected to the National Academy of Sciences in 1989 for his work on neural development and synaptic plasticity, his research during the last 15 years has sought to explain why we see and hear what we do, focusing on the visual perception of lightness, color, form, and motion, and the auditory perception of music and speech. In addition to membership in the National Academy of Sciences, Purves is a fellow of the American Academy of Arts and Sciences and the Institute of Medicine. His books include Principles of Neural Development (with Jeff Lichtman; Sinaur,1985); Body and Brain (Harvard,1988); Neural Activity and the Growth of the Brain (Cambridge, 1992); Why We See What we Do (with Beau Lotto; Sinauer, 2003); Perceiving Geometry (with Catherine Howe; Springer 2005); Why We See What we Do Redux (Sinauer, 2011) and Brains: How they Seem to Work (Financial Times Press, 2011). He is also lead author on the textbooks Neuroscience, (5th edition, Sinauer, 2011), and Principles of Cognitive Neuroscience (2nd edition, Sinauer, 2012). More information, access to publications and a complete CV are available at

Course Description

The purpose of the course is to consider how what we see is generated by the visual system.

In the 1960s and for the following few decades, it seemed all but certain that the rapidly growing body of information about the electrophysiological and anatomical properties of neurons in the primary visual pathway of experimental animals would reveal how the brain uses retinal stimuli to generate perceptions and appropriate visually guided behaviors. But despite the passage of more than fifty years, this expectation has not been met. In retrospect, the missing piece is understanding how stimuli that cannot specify the properties of physical sources can nevertheless give rise to perceptions and behaviors that are routinely successful.

Most concepts of vision propose, explicitly or implicitly, that successful visual behavior depends on recovering the sources of stimulus features either directly or by a process of statistical inference. However, given the inability of the visual system to access the physical properties of the world, these conceptual frameworks cannot account for the behavioral success of biological vision. The alternative is that the visual system automatically links simple, recurrent stimulus patterns with reproductive success, without ever recovering real world properties.

This strategy provides a different way of studying the relationship between the objective world and subjective experience, and offers a way of understanding the operating principles of visual circuitry without invoking feature detection, image representation in the brain, and/or probabilistic inference.

Thus the objectives of the course are:
- To introduce you to some fascinating perceptual phenomenology
- To make you think about how this phenomenology can be explained
- To make you consider what possible explanations imply about brain function


Is this course free?


How is this course different from other Neuroscience (particularly, sensory modality) courses? 

This course will encourage you to consider vision in a new way. In particular, we will discuss how what we see is not a representation of the physical world, and what surmounting this obstacle implies about the visual brain. 

Will I get a Statement of Accomplishment after completing this class?

Yes. Students who receive 70% or better in the class will receive a Statement of Accomplishment signed by the instructor.

What resources will I need for this class?

No course materials are required; students simply need be open to new ideas about the our perception of the physical world and how the visual brain operates.



Module #1: The Phenomenology of What We See

1.1 Introduction 

1.2 The Strange Way We See Things

1.3 Why We Don't See the World the Way It Really Is: The Inverse Problem 

Module #2: Organization of the Visual System

2.1 Visual Stimuli

2.2 Organization of the Visual System: Eye and Retina 

2.3 Organization of the Visual System: The Primary Visual Pathway

Module #3: Conceptions of How Vision Works

3.1 Introduction

3.2 Vision as Feature Detection

3.3 Vision as Inference

3.4 Vision as Efficient Coding

3.5 Vision as a Way of Contending with the Inverse Problem 

Module #4: Seeing Lightness and Brightness

4.1 Introduction

4.2 The Discrepancies between Luminance and Lightness

4.3 Some More Complex Examples

4.4 An Empirical Explanation Based on Reproductive Success

Module #5: Seeing Color

5.1 Introduction

5.2 More about the Nature of Light

5.3 A Review of Some Relevant Retinal Biology

5.4 Why We Have Color Vision

5.5 The Strange Way We See Color: Color Contrast and Color Constancy 

Module #6: Seeing Geometry

6.1 The Phenomenology of Perceived Geometry

6.2 Line Length: An Example of How Perceived Geometry Can be Explained

6.3 The Perception of Angles 

6.4 The Perception of Object Size

Module #7: Seeing Distance and Depth

7.1 Introduction

7.2 Monocularly Perceived Distance

7.3 Binocularly Perceived Depth (Stereopsis)

7.4 Explaining Stereopsis

7.5 Random Dot Stereograms and the Correspondence Problem

7.6 How and Where Does Information from the Two Eyes Come Together?

Module #8: Seeing Motion

8.1 Introduction

8.2 Perceived Speed: The Flash-Lag Effect

8.3 Perceived Direction: Aperture Effects

Summing Up


The content will be presented in 8 modules through video lectures, supplemented diagrams, examples of illusions and other illustrations. The modules are:


1. The Phenomenology of What We See

2. Organization of the Visual System

3. Conceptions of How Vision Works

4. Seeing Lightness and Brightness

5. Seeing Color

6. Seeing Geometry

7. Seeing Distance and Depth

8. Seeing Motion

Summing Up

Each module will have a related quiz consisting of ten relatively basic multiple-choice questions that will be machine graded.

A final paper (1-2 pages), to be peer graded, will also be assigned near the conclusion of the course. The peer assessment will run over a two-week period (submissions will be first week and evaluation the second). Students will evaluate the papers of 5 peers.  A qualitative and quantitative rubric will be supplied to assist students in these evaluations.  

Quizzes will be worth 70% and the final paper 30% of the grade.  Students need to receive a grade of 70% or better to earn a Statement of Accomplishment.   

Suggested Reading

The following is a list of books in which the relevant material is discussed in more detail, but reading them is not required to understand the presentations.

Howe CQ, Purves D (2005) Perceiving Geometry: Geometrical Illusions explained by Natural Scene Statistics. New York: Springer Press.

Hubel DH, Wiesel T (2005) Brain and Visual Perception. A story of a 25-year collaboration. (Oxford University Press, New York).  

Land MF, Nilsson DE (2002) Animal Eyes. Oxford Animal Biology Series. (Oxford University Press, New York). 

Purves D. (2010) Brains: How They Seem to Work. New York: Pearson/ Financial Times Press

Purves D, Augustine GA, Fitzpatrick D, Hall W, LaMantia A-S, McNamara JO, Williams SM (2011) Neuroscience, 5th edition. Sunderland, MA: Sinauer Associates

Purves D, Cabeza R, Huettel SA, LaBar KS, Platt ML, and Woldorff M (2012) Principles of Cognitive Neuroscience, 2nd edition. Sunderland, MA: Sinauer Associates

Purves D, Lotto RB (2011) Why We See What We Do Redux. Sunderland, MA: Sinauer Associates

References to original papers and reviews are provided in an extensive bibliography for students who may want to dig still deeper.

A glossary is also be available to consult when terms are unfamiliar. 

Course Workload

3-4 hours/week

Review course:

Please sign in to review this course.

Similar Courses

{{ }} {{ }}


{{course.start_date | date:'MMM d'}} — {{ course.end_date | date:'MMM d'}}   ({{ course.time_until_course_starts }} ,   length: {{ course.length_in_weeks }} weeks) Self-paced — no deadlines    
${{ course.price }} p/mfree


Course Activity & Community

Be the first Accredible user to join this course!

uploaded {{ feed_item.model.caption || feed_item.model.url || feed_item.model.file_file_name }} for the course {{ }} — {{ feed_item.time_ago }}

{{ }} {{ comment.text | truncate: (comment.length || comment_display_length) }}   read more hide

{{ comment.time_ago }}

started the course {{ }} — {{ feed_item.time_ago }}
followed {{ }} — {{ feed_item.time_ago }}
followed thier friend {{ }} — {{ feed_item.time_ago }}
{{ feed_item.model.text }} (on the course {{ }}) — {{ feed_item.time_ago }}

{{ }} {{ comment.text | truncate: (comment.length || comment_display_length) }}   read more hide

{{ comment.time_ago }}