First, however, we should consider whether there might be a link between speech comprehension and production. It would be simpler for psycholinguists if they were directly related. However, there is no reason to assume this is so, any more than we should presume that the same muscles are used in sucking and blowing. We must therefore allow for four possibilities:

1 Comprehension and production are totally different. 2 Comprehension is production in reverse. 3 Comprehension is the same as production: that is, comprehenders

reconstruct the message for themselves in the same way as they would construct it if they were speakers.