Effect of imaging sentences on concurrent unimanual performance

In Experiment 1, 96 right-handers tapped on a telegraph key while concurrently imaging, overtly rehearsing, or silently rehearsing concrete sentences in a between-subjects design. A strategy control problem for men precluded an interpretation of their data but in women, significantly better recall with imagery than rehearsal was accompanied by comparable right-lateralized manual interference in imagery and overt rehearsal and symmetrical decrement in silent rehearsal. In Experiment 2, overtly rehearsing high imagery sentences produced a trend toward more right left manual asymmetry in 45 right-handers relative to rehearsing low imagery sentences. The outcomes of these two preliminary studies point toward a role for the left hemisphere in sentence imagery beyond its contribution to sentence processing per se.