Mental imagery and production of hand gestures while speaking in younger and older adults

Abstract

Speech and conversational hand gestures were recorded during interviews of 23 younger (M = 21 years) and 19 older adults (M = 70 years). Three kinds of questions were used in order to activate either visual images, motor images, or no mental image (abstract topics). On average, the rate of gesture production did not differ in younger and older adults, but it was significantly influenced by imagery conditions. Gesture production was higher in the motor than in the visual imagery condition, and lowest in the abstract condition. A significant interaction between age and imagery conditions influenced the proportion of representational gestures, which were relatively less frequent in older adults, especially in the visual imagery condition. Content analysis of verbal responses showed that imagery values did not differ in younger and older adults, but that concrete words were less frequent in responses to abstract questions than in the two other conditions. The implications of these results concerning the mechanisms of gesture production and the age-related changes in conversational behavior are discussed.