Working memory following improvements in articulation rate in children with cerebral palsy.

It has been postulated that rehearsal rate is the primary determinant of working memory capacity for verbal material (Baddeley et al., 1975). A previous study of normal control children and children with spastic diplegic cerebral palsy (SDCP) suggested that covert rather than overt rehearsal rate determines working memory capacity (White et al., 1994). In the current study, a subset of SDCP children who received a surgical treatment to relieve spasticity were retested on measures of articulation rate and memory span. A subset of control children from the original study were also retested. The SDCP group showed improvements in articulation rate at follow-up, though memory span did not change and was again equivalent to that of controls. These findings indicate that increases in articulation rate are not necessarily accompanied by improvements in memory span, and provide additional evidence that working memory capacity may be determined by covert rather than overt articulatory rehearsal.