Scrambled

When you raed a sencente, the oerdr
of the ltetres in a word dsnoe't mteatr as long as the fsirt
and lsat ones are in the rhgit pcale.
Last fall, a widely circulated e-mail written in a similarly
garbled fashion reached Denis Pelli, a professor of psychology
at New York University. He set to work figuring out why this
trick works. When a reader focuses on a word, Pelli says, the
eyes take in both central and peripheral views. The eye's periphery
can't focus as narrowly, making it difficult to identify the
letters in the middle of a word, so the brain recognizes the
word as a unit based on the first and last letters, as well
as key features such as dangling g's and tall d's.
If the intervening letters are scrambled, the reader can still
identify the word fairly quickly. Faster readers do this using
sentence context. Pelli finds that when the whole sentence is
scrambled to remove contextual information, slow and fast readers
comprehend individual words, scrambled or not, at nearly the
same rate.