Overview
This Visual Illusions and Perceptual Exercise will illustrate a variety of influences on visual perception and the critical role that context plays in the real world. It will also help you understand the connection between these environmental influences on perception and the neuroanatomy of the visual system.
Upon completion of this assignment you will be able to:
explain the role of context and other visual factors in the creation of optical illusions
interpret how the anatomy and communication in the visual system relates to changes in perception
describe possible sensory system interactions that occur in real-world situations that are related to visual perception
Requirements
Before starting this assignment, be sure you have read Chapter 5 on the visual system and reviewed the resources in Module 3 – Part 1.
Complete the exercise described below and submit your responses by the deadline.
Exercise Preparation
Find a distraction-free area to conduct the exercise.
It is highly recommended that you utilize a desktop, laptop, or tablet device for this exercise. This will not work well on a phone, but if that is all you have, you will need to do the best you can.
Be ready to note observations on a sheet of paper or your device. You will be making observations on at least 5 separate visual activities.
Before opening the link for each illusion/activity, please read all the instructions I’ve given below carefully.
Important: This should be an interesting experience (hopefully), but if any of the visual stimuli make you feel dizzy or overstimulated in any way, please stop, take a break, and let me know. The first one called “Disappearing Dots” is probably the most stimulating visually, so please be careful and skip it if you are concerned. If you have a seizure disorder do not due the first 3. You can just focus on the “Moon Illusion” and “Color interactions with light and sound.”
Exercise
Read the instructions for each activity BEFORE clicking on the link. After reading the instructions, click on the link and complete the activity, noting your perceptions and any factors that influence it along the way.
Disappearing dotsLINK – (https://commons.wikimedia.org/wiki/File:Disappearing_dots.gif#/media/File:Disappearing_dots.gif) (Public domain; Author – Jahobr) – The activity will start right after selecting the link. Once it starts, stare at the small black dot in the center of the picture and note your observations of what you perceive. You just need to view this for about 10 seconds to get the full effect. Please don’t overdo it on this one.
Color afterimage (2)
(Links to an external site.)
LINK – (https://commons.wikimedia.org/wiki/File:Nachbild.png#/media/File:Nachbild.png) (CC-SA,Remix; Author- Mikue) – This activity will also be displayed right after selecting the link. Again, be sure to look at the black dot in the center of the green box for about 20 seconds and then quickly look over at the white box to the right. Note your observations.
(Links to an external site.)
Celebrity Face Perception
(Links to an external site.)
(3) LINK – (https://commons.wikimedia.org/wiki/File:MICHAEL_JACKSON,_Afterimage.jpg#/media/File:MICHAEL_JAKSON,_Afterimage.jpg) (CC – SA, Remix; Author – Dimitri Parant) – This activity will be displayed as soon as you select the link. Prior to selecting the link, you should get a blank piece of white notebook paper. You will want to hold up the paper next to the image once you open it. After selecting the link, immediately look at the small white dot at the top of the nose directly in between the eyes for about 20 seconds. After 20 seconds, immediately look at the white piece of paper and note your observations. Repeat this procedure, but instead of looking at the paper, close your eyes and keep them closed for about 10 seconds and note what you “see.”
Moon illusion
(Links to an external site.)
LINK – (https://www.ted.com/talks/andrew_vanden_heuvel_the_moon_illusion) (TEDed animation ~ 5 min.)
(Links to an external site.)
Just watch this one and take notes.
Color interactions with context and sound
(Links to an external site.)
LINK – (https://www.ted.com/talks/beau_lotto_optical_illusions_show_how_we_see?language=en#t-962735) (TED Talk – Beau Lotto; ~15 min)
This link is to a TED talk with several, short demonstration activities. Please do at least two of these along with the audience. I encourage you to watch the whole video since there is some very interesting material toward the end on the conversion of visual input into sound and the possible therapeutic potential of this process.
2. After completing the activities and watching the videos, answer the questions below. Be sure to include specific details from the text and/or PowerPoint presentation on this material.
Questions
1. Which illusion activities did you find the most interesting and why?
2. For at least one of the activities that focused on aspects of color perception, describe why you think the unusual perception occurs. Make sure to utilize the material related to theories of color perception (tri-chromatic, opponent-process) and the visual circuitry in either the retina or the brain in your answer?
3. Describe your perceptions from at least one other illusion or activity, and speculate on what parts of the visual anatomy in the brain may have been involved and why.