A person can only hold only “so much” information in working memory … here is an anology: There are 5 babies in the bed. Put another one in, and one of the babies in the bed falls out. The bed can only hold “5” babies. Period. This study by Kane et al (2001) published in the Journal of Experimental Psychology further bolsters the theory that our ability to focus and pay attention is largely driven by how many bits of information (“babies”) we can hold in our working memory without losing them in the presence of more bits of information or distractions (“more babies”). Working memory is a skill that is dependent upon timing in the brain. The better the brain’s timing, the better working memory can hold onto the bits of information and use them for the situation (i.e., learning) or problem at hand. Taub et al (2007) have theorized that Interactive Metronome, a patented program that improves timing in the brain, primarily addresses thinking speed and working memory, thereby improving our ability to focus and learn.

Kane, M.J., Blecky, M.K., Conway, A.R.A., and Engle, R.W. (2001) A controlled attention view of working-memory capacity. Journal of Experimental Psychology, 130(2), 169-183.
Taub. G., McGrew, K.S., and Keith, T.Z. (2007). Improvement in interval timing tracking and effects on reading
 achievement. Psychology in the Schools, 44(8), 849-863.

The "Time Doc" (K. McGrew) Voice of America interview on focus and "quieting the busy mind"

Why is a scholar in intelligence theory and testing spending time working with and researching the brain-clock based neurotechnology of Interactive Metronome?
I have now explained this connection on my recent Internet radio show interview. In it you will learn why IM technology appears to increase focus (controlled attention; working memory) in a manner similar to mindfulness meditation and other brain fitness programs. You will learn that these technologies help to "quiet the busy" mind that is due to the default brain network, via the strengthening of the salience and central executive networks. The connection with general intelligence (g) is also discussed via Jensen's neural efficiency hypothesis and the temporal g notion of neural efficiency. If you want to read more, check out the Time Doc's posts at the IM-Home blog (check for posts under my name or under the category of "science"... and be sure to click on "see other stories" if it does not give you all the posts) These include the Time Doc's own personal experience with the IM-Home brain clock based technology... Read more...