The word order of languages predicts native speakers' working memory

Abstract

The relationship between language and thought is controversial. One hypothesis is that language fosters habits of processing information that are retained even in non-linguistic domains. In left-branching (LB) languages, modifiers usually precede the head, and real-time sentence comprehension may more heavily rely on retaining initial information in working memory. Here we presented a battery of working memory and short-term memory tasks to adult native speakers of four LB and four right-branching (RB) languages from Africa, Asia and Europe. In working memory tasks, LB speakers were better than RB speakers at recalling initial stimuli, but worse at recalling final stimuli. Our results show that the practice of parsing sentences in specific directions due to the syntax and word order of our native language not only predicts the way we remember words, but also other non-linguistic stimuli.

Figure 1

Box-plot representing the data distribution for the number of correct initial and final stimuli in WM tasks with numeric, spatial and word stimuli from a generalized linear mixed model (GLMM). The horizontal ends of the box represent the 75% and 25% quartiles, and the ends of the whiskers represent the 97.5% and 2.5% quartiles respectively. The dotted line represents the model estimates.

Figure 2

Box-plot representing the data distribution for the number of correct initial and final stimuli in WM tasks for left-branching (LB) and right-branching (RB) participants from a generalized linear mixed model (GLMM). The horizontal ends of the box represent the 75% and 25% quartiles, and the ends of the whiskers represent the 97.5% and 2.5% quartiles respectively. The dotted line represents the model estimates.

Figure 3

Box-plot representing the data distribution for the number of correct initial (I) and final (F) stimuli in WM tasks for left-branching (LB) participants of each language (Ja = Japanese, Ko = Korean, Na = Khoekhoe, Si = Sidaama), and for right-branching (RB) participants of each language (It = Italian, Kh = Khmer, Os = Oshiwambo, Th = Northern Thai), from a generalized linear mixed model (GLMM). The horizontal ends of the box represent the 75% and 25% quartiles, and the ends of the whiskers represent the 97.5% and 2.5% quartiles respectively. The dotted line represents the model estimates.

Figure 4

Box-plot representing the data distribution for the number of correct initial and final stimuli in STM tasks with numeric, spatial and word stimuli from a generalized linear mixed model (GLMM). The horizontal ends of the box represent the 75% and 25% quartiles, and the ends of the whiskers represent the 97.5% and 2.5% quartile respectively. The dotted line represents the model estimates.