C

Neuroscientists usually investigate one brain at a time. They observe how neurons（神经元） fire as a person reads certain words, for example, or plays a video game. As social animals, however, those same scientists do much of their work together - brainstorming hypotheses, puzzling over problems and fine-tuning experimental designs. Increasingly, researchers are bringing that reality into how they study brains.

Collective neuroscience, as some practitioners call it, is a rapidly growing field of research. An early, consistent finding is that when people converse or share an experience, their brain waves synchronize. Neurons in corresponding locations of the different brains fire at the same time, creating matching patterns, like dancers moving together. The experience of "being on the same wavelength" as another person is real, and it is visible in the activity of the brain.

Such work is beginning to reveal new levels of richness and complexity in sociability. In classrooms where students are engaged with the teacher, for example, their patterns of brain processing begin to synchronize with that teacher's - and greater synchrony may mean better learning. Couples exhibit higher degrees of brain synchrony than non-romantic pairs, as do close friends compared with more distant acquaintances.

But much about the phenomenon remains mysterious - even scientists occasionally use the word "magic" when talking about it. One straightforward explanation could be that synchrony between brains is a result of shared experience or simply a sign that we are hearing or seeing the same thing as someone else. But the newest research suggests that synchrony is more than that - or can be. Researchers are discovering synchrony in humans and other species, and they are mapping its choreography - its rhythm, timing and undulations（波动） - to better understand what benefits it may give us.

Given that synchronized experiences are often enjoyable, researchers suspect this phenomenon is beneficial: it helps us interact and may have facilitated the evolution of sociality. This new kind of brain research might also cast light on why we don't always "click" with someone or why social isolation（孤立） is so harmful to physical and mental health. With synchrony and other levels of neural interaction, humans teach and learn, forge friendships and romances, and cooperate and converse. We are driven to connect, and synchrony is one way our brains help us do it.

8. According to the passage, collective neuroscience __.

A. collects and refines research on neurons

B. analyses activities of one brain at a time

C. promotes connections among neuroscientists

D. focuses on studying brains in interactive groups

29. What can we infer about brain synchrony from Paragraph 4?

A. It can benefit other species.

B. Its mechanism has changed.

C. It demands further investigations.

D. Findings about it are contradictory.

30. Which of the following may result from brain synchrony?

A. Increasing popularity among peers.

B. Better cooperation among teammates.

C. Improved techniques for conversations.

D. More shared experiences between a couple.