Do you really know｜孤独对我们的大脑有什么影响？

What does loneliness do to our brains?

Not everyone has the same relationship with social contact. Introverts, for example, recharge by spending time alone. Meanwhile, extroverts get their energy from being around other people.

But here's the thing. Being introverted or enjoying solitude isn't the same as being lonely. Loneliness can actually become painful and even harmful when it drags on for too long.

What happens when loneliness becomes chronic, then?

It often leads to a drop in motivation and mood. You feel less active and engaged, which can take a toll on both your body and mind, not to mention your social life. And it turns out loneliness might also affect how our brains work.

A study published in BMC Public Health in 2025 followed 172 people aged 25 to 65 over a period of two years. Researchers tested their cognitive abilities through phone-based games. They found that people who weren't chronically lonely improved over time, while those who were stuck in loneliness didn't make much progress at all.

Other studies also show that long-term loneliness increases the risk of depression, anxiety, and even burnout. But that's not all. Loneliness can actually change your brain.

Going back to 2020, researchers at McGill University in Canada analysed MRI scans and genetic data from 40,000 people. They compared participants who said they often felt lonely with those who didn't, and the results were striking.

How does that work then?

The lonely group showed differences in what's known as the default mode network. That's the set of brain regions that lights up when your mind wanders, when you're remembering, planning, or daydreaming.

We talked about the default mode network in a recent episode of Do You Really Know? , which explained why it's important for us to allow ourselves to get bored from time to time.

In lonely people, this network showed stronger connections and even more grey matter. The scientists also noticed changes in the fornix, which is a bundle of nerve fibers linking the hippocampus to that same default network.

Surprisingly, in lonely people, the fornix seem to be better preserved. In other words, loneliness might actually boost imagination. When we lack real social contact, the brain tries to fill the gap.

Nathan Sprang was the lead author of the McGill University study, and in its media release he went on record saying, in the absence of desired social experiences, lonely individuals may be biased towards internally directed thoughts, such as reminiscing or imagining social experiences. There you have it.

词汇表
introvert [ˈɪntrəvɜːt] n. 内向的人，性格内向者
recharge [riːˈtʃɑːdʒ] vt. 恢复精力，补充体力，充电
extrovert [ˈekstrəvɜːt] n. 外向的人，性格外向者
introverted [ˈɪntrəvɜːtɪd] adj. 内向的，性格内向的
solitude [ˈsɒlɪtjuːd] n. 独处，独居；孤独
drag on 持续，延长，拖延
chronic [ˈkrɒnɪk] adj. 长期的，慢性的
take a toll on [təʊl] 对…造成损害，产生负面影响
cognitive ability [ˈkɒɡnɪtɪv] 认知能力
be stuck in 陷入，被困于
burnout [ˈbɜːnaʊt] n. 倦怠，精疲力竭
MRI scan [skæn] 核磁共振扫描
genetic [dʒəˈnetɪk] adj. 基因的，遗传的
striking [ˈstraɪkɪŋ] adj. 惊人的，引人注目的
default mode network [dɪˈfɔːlt məʊd ˈnetwɜːk] 默认模式网络（指大脑在静息状态下，即没有进行特定任务时活跃的一组脑区）
brain region [ˈriːdʒən] 大脑区域，脑区
light up 被激活，变得活跃
mind wanders [ˈwɒndəz] 思绪飘散，走神
grey matter 灰质（大脑负责信息处理的关键部位）；脑力，智力
fornix [ˈfɔːnɪks] n. 穹窿（连接海马结构和其他脑区的神经纤维）
a bundle of [ˈbʌndl] 一束，一捆，一大堆
nerve fiber [nɜːv ˈfaɪbə(r)] 神经纤维（负责传导神经冲动）
hippocampus [ˌhɪpəˈkæmpəs] n. 海马体（与记忆储存转化有关）
fill the gap [ɡæp] 填补空白，弥补不足
go on record 公开表明，公开发表（观点等）
desired [dɪˈzaɪəd] adj. 渴望的，期望的，想得到的
be biased towards [ˈbaɪəst] 倾向于，偏向于
internally directed thoughts [ɪnˈtɜːnəli] 内向性思考，内倾性思维
reminisce [ˌremɪˈnɪs] vi. 回忆，追忆往事

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