Understanding developmental language disorder - the Helsinki longitudinal SLI study (HelSLI): a study protocol

BMC Psychology

Table 1 Structure of the HelSLI study: the schedule of enrolment, questionnaires and assessments

Timepoint			Pre-study		Onset											Follow-ups
Timepoint			t₀₀		t₀											t₁	t₂	t₃
Group	Language	Age at Onset	Assessment
Group	Language	Age at Onset	Informed consent	Background information	Genetic saliva sample	Neuropsychological	Speech and language therapist	STM and AGL tablet tasks	SDQ, ASEBA, CCC-2^a	Medical examination	Clinical EEG	ERP	Video-taped play sessions	Temperament questionnaire	ALDeQ, ALEQ^b	Speech and language therapist	Speech and language therapist	Speech and language therapist
DLD	Monolingual	3 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓				✓
		4 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓			✓
		5 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓		✓
		6 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
	Bilingual	3 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓				✓	✓	✓	✓
		4 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓				✓	✓	✓
		5 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓				✓	✓
		6 yrs	✓	✓	✓	✓	✓	✓	✓	✓	✓				✓
TD	Monolingual	3 yrs	✓	✓	✓	✓	✓	✓	✓							✓	✓	✓
		4 yrs	✓	✓	✓	✓	✓	✓	✓							✓	✓
		5 yrs	✓	✓	✓	✓	✓	✓	✓
		6 yrs	✓	✓	✓	✓	✓	✓	✓
	Bilingual	3 yrs	✓	✓	✓	✓	✓	✓	✓						✓	✓	✓	✓
		4 yrs	✓	✓	✓	✓	✓	✓	✓						✓	✓	✓
		5 yrs	✓	✓	✓	✓	✓	✓	✓						✓	✓
		6 yrs	✓	✓	✓	✓	✓	✓	✓						✓

DLD developmental language disorder, TD Typically developing
Time points: t₀₀ = enrolment; t₀ = entering the study at age 3–6 years; t₁, t₂, t₃ = yearly follow ups, last follow up at age 6. STM Short-term memory, AGL Artificial grammar learning, SDQ Strengths and difficulties questionnaire, ASEBA Achenbach System of Empirically Based Assessment, CCC-2 Children’s communication checklist, EEG Electroencephalography, ERP Event-related potential, ALDeQ Alberta Language Development Questionnaire, ALEQ Alberta Language Environment Questionnaire
^aMonolinguals: Parents and Kindergarten, Bilinguals: Kindergarten only
^bParent reports on first language development and language environment

ISSN: 2050-7283