Performance on the measures cognitive flexibility, inhibition, processing speed and phonological short-term memory was assessed. The monolingual, Caucasian study sample consisted of 30 children with SLI (Mage = 63.3 months, SD = 4.3 months) and 30 healthy controls (Mage = 62.2 months, SD = 3.7 months). Groups were matched for age and nonverbal IQ. Socioeconomic status of the participating families was included.
Children with SLI had significantly poorer abilities of phonological short-term memory than matched controls. A tendency of poorer abilities in the SLI group was found for inhibition and processing speed.
We confirmed phonological short-term memory to be a reliable marker of SLI in preschoolers. Our results do not give definite support for impaired executive function in SLI, possibly owing to limited sensitivity of test instruments in this age group. We argue for a standardization of executive function tests for research use.