DO ALL SPEECH-DISORDERED CHILDREN HAVE MOTOR DEFICITS

The performance of four groups of speech-disordered children and a nor mal control group on tasks assessing volitional and non-volitional ora l movements, fine motor skills and speech motor planning (novel word l earning) were compared. Children whose phonological and/or articulatio n skills were slowly following the normal course of development did no t appear to have specific difficulty on any of the experimental tasks. Children who consistently used non-developmental phonological rules d id not differ from normal controls on tasks which assessed speed, dext erity and co-ordination of fine motor movements, indicating that their deficit is not one of motor control or implementation, motor planning or integration of perceptual and motor information. Further, the resu lts of the new-world learning task demonstrated that they are as good as the control group when learning to recognize and say new words. Chi ldren who made inconsistent speech errors performed as well as normal controls on tasks which assessed the function of the lips and tongue i n a non-speech context, and the ability to sequence two non-speech ora l movements, eliminating an ore-motor implementation deficit. However, they were significantly poorer than controls on tasks which required speed and dexterity of fine motor movements, indicating that children with inconsistent deviant phonology had more difficulty organizing com plex sequences of movement when time was included as a performance fac tor. Children diagnosed as having developmental verbal dyspraxia had d ifficulty on the fine motor subtests, reflecting deficits at the level s of integrating sensory information into a plan of action, and at the level of co-ordinating speed and dexterity of intricate movements. Th e theoretical and clinical implications of these results are discussed .