About language and mistakes

There is an article today on Yahoo about language, What your verbal fillers say about you, that I think you may find both interesting and enlightening.
This article has made me think. I'm getting old and one of the signs is the number of mistakes I make every day regarding language. I don't mean grammar or vocabulary mistakes (which I also make but for a different reason: my command of the language, either English or Spanish, is far from perfect) but those slips of the tongue and pen you have sometimes witnessed.
So, too often I think pen but say paper or mean sausage but say hamburger. Slips of the pen (when you think of a word but write another) are fortunately much less frequent but nevertheless as worrying. It is also difficult sometimes to find the right word and I'm very often at a loss for words and unable to say what I really mean. Michael Erard in his book “Um ... ” confirms this: age is an important factor

In his informal study of verbal mistakes, he states that the average person will commit somewhere between 7 and 22 slips of the tongue each day and from two to four times a day will struggle, for an embarrassing length of time, to find the right word or name. It only gets worse. As the years go by, speech reverts to childhood levels of disfluency, with more pauses, more errors, more repeated words, but even the peak years are not great: up to 8 percent of the average person’s word output consists of meaningless fillers and placeholders like um, uh and er. The simplest explanation for all verbal mistakes, Mr. Erard writes, is that they occur “as the brain shifts from planning to executing or back again.” They also, most linguists agree, follow the structure of the language.