The Internet – that strange place where sound moves faster than light

I was giving a live web presentation today to demonstrate some software. I was using Blackboard Collaborate, the offspring of the mating of Elluminate and Wimba, a very nice platform for this purpose.

As sometimes happens when using web conferencing software like this, the video part of the live demostration was taking longer to arrive in the participants’ broswers than the audio part. The amount of data that is needed to support live streaming video is much greater than the amount of data that is needed to support live streaming audio, and therefore sometimes the pictures follow the words.

It struck me that this creates a strange illusion on the web, an illusion that sound is faster than light. In the physical world, of course, light is faster than sound. Go to any fireworks display and witness the phenomena for yourself.

Learning is not enhanced when our virtual world does not match what we expect to see in our physical world. Audio and images out of sync creates a cognitive dilemma for the brain that has to work harder to try to match up content that is out of sequence, and reconstruct it in the correct sequence. This uses up scarce resources in working memory that would otherwise be used to process the content of the activity, not the modalities of the media.

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Choke book coverWhether you are sitting for an important test or sinking a winning golf putt, your brain can get in the way when you need to perform at your very best. Ginger Campbell, MD, of the Brain Science Podcast interviews psychology researcher Sian Beilock about her book, Choke: What the Secrets of the Brain Reveal About Getting It Right When You Have To.

This excellent interview regarding research conducted at Beilock’s Human Performance Lab at the University of Chicago provides some great insights into how the brains of high performers can interfere with delivering an expert performance when it matters most. Beilock doesn’t stop at explaining the many different reasons why someone might choke on a test, a job interview, a speech, or an athletic game. She offers many practical suggestions for how to overcome the memory overload that can impede top performance.

This is really valuable information for students and their teachers. Beilock says high performers are more likely to choke on a test than students with lesser skills. This seems counter-intuitive until she explains that these higher performers generally have greater working memory to help them perform highly complex cognitive tasks, but this working memory can become flooded by anxiety and worry, significantly limiting the amount of working memory available for the task, resulting in a less than optimal performance.

Beilock describes research that shows that 10 minutes of free writing about these feelings and anxieties can relieve the worries enough to free up that valuable working memory for the cognitive tasks and performance can return to normal.

The interview is filled with interesting research findings and concrete suggestions about mitigating performance problems. Brain Science Podcast host Ginger Cambell does a nice job leading Beilock through many different aspects of her research in a presentation that is easy to follow and full of practical advice. Be sure to take a look at previous episodes of the Brain Science Podcast for some fascinating interviews with many of the world’s leading neuroscience researchers.

Source: brainsciencepodcast.com

Working memory: "the bottleneck is not in the remembering, it is in the perceiving"

That quote is probably the most important sentence I have read in a year.

Working memory refers to the number of things a person can actively hold in memory at once, such as numbers or colors. Most people can remember about four things at once, and some can remember more.

MIT neuroscientists have found that the limitations on working memory do not come from limitations on remembering. Instead they come from how many things can be accurately perceived at once. We bump up against limits in visual perception in the process of encoding things into working memory even before we try to recall those things.

It gets better. The study also found that we do not have a working memory, but actually have working memories — two of them — one in each of the right and left hemispheres of the brain. The researchers concluded that the typical limit of four items in working memory at once was actually a limit of two items in the working memory of each of the two hemispheres.

“The fact that we have different capacities in each hemisphere implies that we should present information in a way that does not overtax one hemisphere while under-taxing the other,” said Timothy Buschman, the researcher who conducted the study.

I’ve been aware of the limits of working memory, and how this impacts the design of learning content in instructional technology, from research by Ruth Colvin Clark and Richard E. Mayer. The two ideas from Buschman’s study, though, raise some interesting additional questions.

What does it mean to balance the cognitive load between the left and right hemispheres? How should the visual design of instructional content reflect this idea? What could be done in content presentation that might increase the capacity or accuracy for visual perception in each hemisphere? How does pedagogy change if we recognize that perception is more important than recall in the capacity of working memory?

We already know that content delivered simultaneously through multiple modalities — such as visual and auditory — can increase the capacity of working memory. Does working memory related to other modalities also function as a dual system? Could this mean we actually have four (or more) distinct working memories that operate as an integrated system?

Education focuses so heavily on recall and pays so little attention to perception. This suggests that we really ought to consider whether we have things backwards.

— Visual Turn

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