The motor cortex, the part of the brain involved in the planning, control, and execution of voluntary movements, may play a role in translating vocabulary from foreign languages into a person’s native language. The corresponding study was published in the Journal of Neuroscience.
The role of the motor cortex in cognitive and perceptual tasks is controversial. Some argue that motor and cognitive processes are functionally related and point to studies in which clinical and neural data show brain regions integrating motor and cognitive functions. Others suggest that motor function is almost independent of cognition, except for when ideating movement.
Responses in a certain area of the primary motor cortex have previously been correlated with vocabulary learning. To investigate this further, researchers conducted experiments on whether the motor cortex plays a role in translating foreign language vocabulary.
To do so, they taught both men and women words in a foreign language alongside a gesture or a picture over four consecutive days. After training, participants translated words that they had learned.
While translating words, the researchers applied repetitive transcranial magnetic stimulation (rTMS) to an area of the primary motor cortex to interfere with their motor cortex processing, or a control rTMS, that did not interfere with motor processing.
The scientists found that rTMS interference in the motor cortex slowed down the translation of words learned alongside genstures. It, however, had no effect on translating words learned alongside images. The control rTMS also had no effect on words learned alongside gestures.
“Interestingly, the effect occurred for both concrete words such as violin and abstract words such as democracy. Taken together, the findings suggest that our memory for recently-learned foreign language words depends on the sensorimotor context in which the words were experienced during learning,” said first author of the study, Brian Mathias.
“Many often-used teaching methods for learning new foreign language vocabulary rely on only audio or visual information, such as studying written word lists. Our findings shed light on why learning techniques that integrate the body’s motor system typically outperform these other learning strategies," he added.