ABSTRACT
Among age-old speculations about the origins of human language is a suggestion that use of the oral channel evolved to leave the hands and the rest of the body free for other activities. True or not, there are few human activities that proceed unaccompanied by talking or listening. With the scope of everyday activities expanding to include some that are life-threatening unless performed with sufficient care, questions about the demands of language use on attention to other things have assumed new priority. This new priority runs up against an old, unresolved, but theoretically central psycholinguistic debate over how language production and language comprehension are related to each other. The terms of this relationship involve shared or divided components of linguistic knowledge and shared or divided resources of perceptual, motor, and cognitive skill. Our question in this chapter is how production and comprehension differ in their demands on attention or working memory (Baddeley, 2003), as reflected in how much production and comprehension interfere with other tasks. At bottom, we are interested in whether talking is harder than listening.
