Scientists have recently found that there are two brain pathways involved how we perceive our own thumping heart.

    科學家們最近發現，大腦中有兩種方式感知我們自己的心跳。

    Hearing Our Heartbeat

    The other day my 3-year old God son and I were pillow fighting when he sat down, panting, and said with surprise, "I can feel my heart beating!" Sometimes it takes little kids to remind us just how amazing our bodies are.

    Scientists believe that an area of the brain, the interior and anterior cingulate cortex, is involved in what is known as interoceptive awareness-the awareness of our own physiological sensations, like a heart beating deep within your body.

    But recent research from the University of Iowa has shown that we can also use another separate pathway when we consciously experience our internal physical states.

    This second pathway, they believe, runs from the skin to the somatosensory cortex, which is the part of the brain that maps the external body.

    The results came from a study with a neurological patient, "Roger," who has been studied in the lab for 15 years, after suffering brain damage from herpes simplex encephalitis. Roger has nearly complete damage to his insula and anterior cingulate cortex, but his somatosensory cortex is completely intact.

    Researchers injected 11 healthy male subjects and Roger with a synthetic form of adrenaline, which made their pulses' shoot up by 25 beats per minute.

    Roger felt his heartbeat as clearly as the other subjects, although slightly delayed. Researchers suspected Roger's brain registered his heartbeats from the surface of his chest wall and from blood vessels pulsating under his skin. To confirm this they anesthetized his skin in specific areas, and administered adrenaline again.

    The healthy subjects felt their heartbeat, as before. But Roger felt nothing.

    This study suggests that both brain pathways are involved in interoceptive awareness, which can cover anything from a panic attack, to the sick-feeling of rejection, to a pounding heart from an afternoon pillow fight.

    傾聽我們的心跳

    有一天我三歲的教子和我玩兒枕頭大戰，當他歇下來的時候，他氣喘吁吁驚奇說道： "我能聽到我的心跳！" 有時候，我們需要小孩子提醒才想起我們的身體是多么的神奇。

    科學家們認為，大腦中的內扣帶皮質和前扣帶皮質與我們所知的內感受性知覺有關，內感受知覺是我們對自己身體感受的一種感知，比如我們體內的心跳。

    但是最近來自衣阿華大學（University of Iowa）的研究表明，當我們有意識經歷我們內部身體情況的時候，我們也能使用另外一種獨立的感知途徑。

    科學家們相信，這第二種感知途徑從皮膚延伸到體感皮質---體感皮質是大腦中對外部身體提供信息的結構。

    該研究結果來自于對一名神經患者"Roger"的研究，Roger由于患單純皰疹病毒性腦炎致使其大腦受到了損害。研究人員在實驗室對Roger進行了15年的研究。Roger的內扣帶皮質和前扣帶皮質幾乎完全損壞，但是他的體感皮質完好無損。

    研究人員向Roger和11名健康的受試者注射了一種合成腎上腺激素，這種激素能讓他們的脈搏跳動頻率每分鐘增加25次。

    Roger和其他受試者一樣，也能清晰地感受到他的心跳，只不過他感受到的時間稍晚一點兒。研究人員推測Roger的大腦從他的胸腔壁和皮膚下跳動的血管記錄了他的心跳。為了證實這一點，研究人員對Roger特定皮膚的部位進行了麻醉，然后再注射腎上腺激素。

    健康的受試者仍然能感受到他們的心跳。但是Roger什么也感受不到。

    該項研究表明，在內感受性知覺中，大腦中的兩種感知途徑都參與了。內感受性知覺包括許多感覺，這些感覺包括從恐慌、被拒后的沮喪心情、到午后枕頭大戰之余的怦怦心跳。

    Vocabulary:

    Perceive:感知

    Thump:強有力的跳動；重擊

    Pant:氣喘吁吁

    Interior cingulate cortex:內扣帶皮質

    Aanterior cingulate cortex:前扣帶皮質

    Interoceptive awareness:內感受性知覺

    Physiological:生理的

    Sensation:感覺；感受

    Consciously:有意地

    Internal:內部的

    Somatosensory cortex:體感皮質

    Neurological:神經性的

    Herpes simplex encephalitis:單純皰疹病毒性腦炎

    Intact:原封不動的；未受損傷的

    Inject:注射

    Adrenaline:腎上腺激素

    Delay:延遲

    Suspect:推測；猜測

    Pulsate: 跳動

    Anesthetize: 麻醉

    Specific: 特定的