Figure 1.
Acquisition of multilingualism in the studied population.
Part A. Typical progression: sequential and increasing process of learning and practicing multilingualism. (For each stage of multilingualism, either individuals stayed at a specified level, or they progressed to the next step i.e. they learned an additional language.) Description of the 6 models of progression found among the 168 individuals for which the learning process represents the acquisition of one language after another (keeping the practice of all of them). Part B. Atypical and unordered progression of learning and practicing multilingualism. Illustration of the 6 models of atypical progression exhibited by the 64 subjects learning 2 or 3 languages in the same period of time and/or losing the practice of one or 2 languages at some point in their lives.
Table 1.
Characteristics of participants.
Figure 2.
Association between different stages of multilingualism and CIND.
Forest plot of the OR comparing different stages of multilingualism over lifetime, to bilingualism, trilingualism and/or quadrilingualism. The solid vertical line shows an OR of 1 (no effect). Each multilingual status is represented by a square, the size of which shows the corresponding sample size in the analysis. The symbols represent the four different analysis performed. The lozenge at the top shows the overall effect of speaking “more than two languages” versus “exactly two languages”. The CL for each situation is represented by a horizontal line and the lower and upper control limits are indicated next (LCL, UCL).
Table 2.
Odds ratio for occurrence of CIND for practicing cognitively stimulating activities and multilingualism during lifespan.