Visweek 2011 – Perception and Cognition for Visualization, Visual Data Analysis & Computer Graphics
Bernice E. Rogowitz covered fundamentals in human perception and cognition, and discussed how they apply to visualization. She covered a huge array of topics, ranging from the pupil being partially responsible for our depth perception, all the way to color theory and how it relates directly to the biology of the human eye.
The presentation had a great flow, starting at a very high level to give everyone an idea of what questions they would be able to answer at the end. As the talk progressed, she covered detailed biological details of the human eye, and progressed to the intersection of perceptual issues and computer science.
In the biological portion, we learned that there are five layers of cells in the retina, each responsible for different tasks. Much of the interesting stuff happens at the very beginning (photoreceptor distribution) and then further into the process at the ganglion cells. She went over how lateral inhibition is caused by the spatial distribution of the photoreceptors connected to a single ganglion cell, and how this is the reason for several of the optical illusions we perceive. She did a great job of explaining the connections between biology and perceptual issues.
Cultural differences were also addressed. The eye movements we have are actually learned when we learn how to read. Cultures with different reading directions have substantially different reading directions.
The section on the Striate Cortex was especially interesting. This is the first time in the visual system that images from each eye are merged (the point where depth perception occurs). This section sends output to 60% of the brain! This is a huge amount, and makes the visual system incredibly important to the decision making process.
This tutorial had a huge quantity of useful information and was really well put together! She concluded with a great summary of four things to remember:
- There are different response rates for different stimuli, how well do you want to convey magnitude information?
- Color and luminance mechanisms have different spatial sensitivities.
- Certain visual information is perceived “pre-attentively” such as color.
- How the world is perceived depends on what the user is trying to accomplish.