Fig. 1

SPIRIT figure for the schedule of enrolment, interventions, and assessments. P primary outcome measure, S secondary outcome measure, −t2 telephone screening, −t1 face-to-face screening, t1 pre-assessment, t2 language course/waiting period, t3 post-assessment, t4 3-month follow-up assessment, t5 language course, t6 4-month follow-up assessment (waiting list control group only). Abbreviations: CFD Cognitive Functions Dementia, CRIq Cognitive Reserve Index questionnaire, DSB Digit Span Backwards, DSF Digit Span Forwards, FLANDERS Flinders Handedness Survey, INHIB Response Inhibition, LLG Language learning group, LSBQ The Language and Social Background Questionnaire, NBV N-Back Verbal, STROOP Stroop Interference Test, SWITCH Task Switching, TMT-A/−B Trail-Making Test – Langensteinbach Version part A/part B, WAFA Perception and Attention Function Battery – Alertness, WAFG Perception and Attention Function Battery – Divided Attention, WIWO Vienna Verbal Fluency Test, WLCG Waiting list control group