hce_cmu
107年
英文
第 47 題
📖 題組：
Among scientists, there are tentative signs of a psychedelics renaissance. After decades of stigma, impressive research is showing the power of these “dubious” substances to help sufferers of depression and addiction, or to comfort patients with a terminal cancer diagnosis, struggling to face their own end. This is a territory that fascinates brain scientists in their venture into human consciousness as effected by the use of psychedelics, drugs that produce hallucination and apparent expansion of consciousness. One of the most interesting early findings of recent psychedelic research is that activity in the “default mode network” (DMN) falls off sharply during the psychedelic experience. This network is a critical hub in the brain that links parts of the cerebral cortex to deeper and older structures involved in memory and emotion. The DMN appears to be involved in a range of “metacognitive” functions such as a self-reflection, mental time travel, theory of mind (the ability to imagine the mental states of other people) and the creation of the so-called “autobiographical self”—the process of weaving what happens to us into the narrative of who we are, thereby giving us a sense of a self that fixates over time. (Curiously, fMRI’s of the brains of experienced meditators show a pattern of activity, or quieting of activity, very similar to that of people who have been given psilocybin, the so-called “magic mushroom.”) When the default mode network is taken captive by a psychedelic, not only do we experience losing the sense of having a self, but myriad new connections among other brain regions and networks spring up, connections that may manifest in mental experience as hallucination (when, say, your emotion centers talk directly to your visual cortex), synesthesia (as when you can see sound or hear flavors) or, possibly, fresh and even inspiring perspectives. Disturbing a complex system is a great way to force it to reveal its secrets and elicit its potentials—and psychedelics allow us to do that to normal ego-centered consciousness.
Among scientists, there are tentative signs of a psychedelics renaissance. After decades of stigma, impressive research is showing the power of these “dubious” substances to help sufferers of depression and addiction, or to comfort patients with a terminal cancer diagnosis, struggling to face their own end. This is a territory that fascinates brain scientists in their venture into human consciousness as effected by the use of psychedelics, drugs that produce hallucination and apparent expansion of consciousness. One of the most interesting early findings of recent psychedelic research is that activity in the “default mode network” (DMN) falls off sharply during the psychedelic experience. This network is a critical hub in the brain that links parts of the cerebral cortex to deeper and older structures involved in memory and emotion. The DMN appears to be involved in a range of “metacognitive” functions such as a self-reflection, mental time travel, theory of mind (the ability to imagine the mental states of other people) and the creation of the so-called “autobiographical self”—the process of weaving what happens to us into the narrative of who we are, thereby giving us a sense of a self that fixates over time. (Curiously, fMRI’s of the brains of experienced meditators show a pattern of activity, or quieting of activity, very similar to that of people who have been given psilocybin, the so-called “magic mushroom.”) When the default mode network is taken captive by a psychedelic, not only do we experience losing the sense of having a self, but myriad new connections among other brain regions and networks spring up, connections that may manifest in mental experience as hallucination (when, say, your emotion centers talk directly to your visual cortex), synesthesia (as when you can see sound or hear flavors) or, possibly, fresh and even inspiring perspectives. Disturbing a complex system is a great way to force it to reveal its secrets and elicit its potentials—and psychedelics allow us to do that to normal ego-centered consciousness.
All of the following can be inferred about “default mode network” EXCEPT
- A Its complicated system can be destabilized by psychedelics.
- B It enables human beings to have a balanced sense of selfhood.
- C Its metacognitive functions are likely to offset hallucination.
- D It coordinates the parts of brains in charge of emotion and memory.
- E Its temporary shutdown may result in synesthesia or hallucination.
思路引導 VIP
請試著在文章第二段找找看：當一個人進入幻覺狀態（hallucination）或失去自我感時，大腦中的「預設模式網路」（DMN）活動量是增加了，還是減少了？這兩者之間存在著什麼樣的因果關係？
🤖
AI 詳解
AI 專屬家教
太棒了！你能精準地從段落中繁雜的腦科學術語裡，辨識出「預設模式網路」（DMN）與幻覺之間的邏輯關係，這代表你對長難句的解析能力非常紮實。
腦部網絡的協調與失序
文中提到 DMN 是連接大腦皮層與情緒、記憶中心的關鍵樞紐，負責建構我們的「自傳式自我」（autobiographical self），這驗證了選項 (B) 與 (D) 的正確性。而當這些物質進入大腦，DMN 的活性會「急劇下降」或被「奪取控制權」，進而引發幻覺或共感覺（synesthesia），這說明了 (A) 與 (E) 描述的穩定性破壞與副作用是符合文意的。然而，選項 (C) 指出元認知功能會「抵消」（offset）幻覺，這與文中「DMN 功能受干擾（包含元認知功能）才是導致幻覺產生」的因果邏輯完全相反，因此是錯誤的推論。
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