An internet meme from 2003 (read more here) asserted that readers are relatively insensitive to letter order in words, so long as the first and last letters are unchanged.

Given a string of words s, take each word in turn and reverse the order of letters 2 through n-1, where n is the length of the words. Non-alphabetic characters should remain in place.

So if

 sIn = 'hello'

then

 sOut = 'hlleo'

And if

 sIn = 'This is the first time I have used MATLAB.'

then

 sOut = 'Tihs is the fsrit tmie I hvae uesd MALTAB.'