語彙学習のタイミング
Hello everyone, SCIENSPOT is a podcast that shines a spotlight on the latest scientific
technology from Japan. Your host is REN from SCIEN-TALK. Today I am looking at a new research
coming from several major Japanese universities. This study uses brain science to solve a long-standing
question in language education. When is the best time to practice vocabulary?
Foreign Language Teaching. Our influential method is task-based language teaching,
TBLT. TBLT emphasizes learning by doing through meaningful communication tasks like solving a
real-world problem or exchanging information. The core dilemma is how to integrate vocabulary
instruction into this communicative approach. Should learners practice new words before
they start the task or after they have completed it? Practicing beforehand or pre-task practice can
prepare learners and boost their confidence. However, some educators worry that too much
脳の活動とコミュニケーション
preparation turns the task into a forced exercise detracting from genuine communication.
To study this complex trade-off, the researchers employed a cutting-edge neuroscience technique
called FNIRS hyperscanning. This allows them to simultaneously measure the brain activity of
two interacting partners while they talk. The key metric they measured is inner brain synchronization
IBS, which essentially tells us how much the two brains are in sync. High IBS often indicates
that the communication is smooth and their partners are successfully coordinating their
thoughts and intentions. The study involved 80 Japanese university students learning English,
forming 40 pairs. These pairs were randomly assigned to either the pre-task or the post-task
vocabulary practice group. The students performed interactive communication tasks
where they had to describe the spy's route using specific English verb-noun combinations
語彙練習の影響
like a fly drone. Crucially, the researchers measured two things one week later,
lexical learning accuracy and neurological synchronization during the communication task.
They focused on two brain areas, the left lateral prefrontal cortex linked to language processing,
and the medial prefrontal cortex involved in social cognition and understanding others'
intentions. The findings on learning outcomes were clear. Pre-task vocabulary practice led to
greater lexical learning. Participants who practiced the target vocabulary before the task
showed significantly higher accuracy one week later in both translation and narrative tasks.
This confirms that developing the initial declarative knowledge, knowing the words
formed and the meaning before using it in context enhanced memory consolidation.
If your goal is to remember the words accurately, practice beforehand. However,
the brain activity told a different story regarding communication processes.
語彙練習の効果
The post-task practice group showed significantly higher IBS in the left LPFC,
the language processing area, during the communication task compared to the pre-task
group. Why did the brain think better when they practiced after the task?
The researchers suggest that tackling the communicative challenge first promotes
cooperating problem solving, which requires intense real-time neural coordination between
partners. In contrast, practicing before the task might have caused the pre-task group to focus too
hard on producing the practice vocabulary accurately, potentially hindering the natural
synchronized neural coordination needed for genuine back-and-forth communication.
This supports the concern that excessive focus on a form can disrupt the communicative process.
Furthermore, the study showed that a higher IBS in the social cognition area
always predicted better learning outcomes, regardless of the timing.
語彙練習のタイミング
This highlights the importance of mutual collaboration for successful learning through
interaction. These results revealed a significant trade-off based on timing.
If the goal is to maximize the accurate retention of specific vocabulary,
practicing before the communication task is more effective. But if the goal is to enhance
the process of collaboration and deepen mutual understanding during interaction,
allowing students to engage in the task first than practicing afterwards is beneficial,
as it promotes higher inter-brain synchronization. For teachers, this means they must strategically
ask themselves, what is the main goal of this lesson? Accuracy or deeper communicative engagement?
The answer dictated when vocabulary interaction should happen.
ポッドキャストの締め
That's all for today's SciencePod. This podcast is broadcast in both Japanese and English.
I'd love for you to listen to the podcast and post your thoughts with hashtag SciencePod.
Thank you for listening and see you next time.
