Hemispheric differentiation and dream recall: subjective estimates of sleep and dreams in different handedness groups.

Previous investigations pointed to a relationship between hemispheric asymmetry and dream recall. Since handedness may reflect the extent to which cerebral organization is lateralized, it was hypothesized that differences in dream recall might exist between different handedness groups. A selected sample of 78 college students (38 right-handers, 25 left-handers, 15 mixed-handers) completed a seven-day sleep and dream diary upon final awakening, at home. Results showed that significantly more dreams are recalled by females compared to males and by right-handers compared to mixed-handers and left-handers. The latter finding is tentatively interpreted as due to a more direct access to aspects of oneiric material structured in the left hemisphere by right-handers, whose language centers are located in the same hemisphere. Unexplained findings of the only other investigation concerning handedness and sleep variables (Hicks, Pellegrini & Hawkins, 1979), which showed greater variability of sleep duration in mixed-handers, were not confirmed by the present study.