When considering this data, research teams couldn’t help wondering: what if the use of certain tools, which involves complex movements, relies on the same brain resources as those mobilized in complex linguistic functions such as syntax?
Syntax exercises and use of tongs
In 2019, Inserm researcher Claudio Brozzoli in collaboration with CNRS researcher Alice C. Roy and their team had shown that individuals who are particularly proficient in the use of tools were also generally better at handling the finer points of Swedish syntax.
In order to explore the subject in greater depth, the same team, in collaboration with CNRS researcher Véronique Boulenger, developed a series of experiments that relied on brain imaging techniques (functional magnetic resonance imaging or MRI) and behavioral measurements. The participants were asked to complete several tests consisting of motor training using 30 cm-long pliers and syntax exercises in French. This enabled the scientists to identify the brain networks specific to each task, but also common to both tasks.
They discovered for the first time that the handling of the tool and the syntax exercises produced brain activations in common areas, with the same spatial distribution, in a region called the “basal ganglia”.
Given that these two skill types use the same brain resources, is it possible to train one in order to improve the other? Does motor training with the mechanical tongs improve the understanding of complex phrases? In the second part of their study, the scientists looked at these issues and showed that this is indeed the case.
This time, the participants were asked to perform a syntactic comprehension task before and after 30 minutes of motor training with the pliers. With this, the researchers demonstrated that motor training with the tool leads to improved performance in syntactic comprehension exercises.
In addition, the findings show that the reverse is also true: training of language faculties, with exercises to understand sentences with complex structure, improved motor performance with the tool.
Motor training and syntax exercises
The motor training involved using the pliers to insert small pegs into holes that matched their shape but with differing orientations.
The syntax exercises which were completed before and after this training consisted of reading sentences with a simple syntax, such as “The scientist who admires the poet writes an article” or with a more complex syntax, such as “The scientist whom the poet admires writes an article.” Then the participants had to decide whether statements such as “The poet admires the scientist” were true or false. Sentences with the French object relative pronoun “que” are more difficult to process and therefore performance was generally poorer.
These experiments show that after motor training, the participants did better with the sentences that were considered to be more difficult. The control groups, which performed the same linguistic task but after motor training using their bare hands or no training at all, did not show such an improvement.