The mysterious science of pain - Joshua W. Pate
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0:07 - 0:10In 1995, the British Medical Journal
-
0:10 - 0:14published an astonishing report
about a 29-year-old builder. -
0:14 - 0:18He accidentally jumped
onto a 15-centimeter nail, -
0:18 - 0:22which pierced straight through
his steel-toed boot. -
0:22 - 0:28He was in such agonizing pain that even
the smallest movement was unbearable. -
0:28 - 0:32But when the doctors took off his boot,
they faced a surprising sight: -
0:32 - 0:36the nail had never touched
his foot at all. -
0:36 - 0:37For hundreds of years,
-
0:37 - 0:42scientists thought that pain was
a direct response to damage. -
0:42 - 0:47By that logic, the more severe an injury
is, the more pain it should cause. -
0:47 - 0:50But as we’ve learned more about
the science of pain, -
0:50 - 0:55we’ve discovered that pain and tissue
damage don’t always go hand in hand, -
0:55 - 1:00even when the body’s threat signaling
mechanisms are fully functioning. -
1:00 - 1:05We’re capable of experiencing severe pain
out of proportion to an actual injury, -
1:05 - 1:08and even pain without any injury,
-
1:08 - 1:12like the builder, or the well-documented
cases of male partners -
1:12 - 1:18of pregnant women experiencing pain
during the pregnancy or labor. -
1:18 - 1:20What’s going on here?
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1:20 - 1:23There are actually two phenomena at play:
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1:23 - 1:28the experience of pain, and a biological
process called nociception. -
1:28 - 1:32Nociception is part of the nervous
system’s protective response -
1:32 - 1:35to harmful or potentially harmful stimuli.
-
1:35 - 1:37Sensors in specialized nerve endings
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1:37 - 1:41detect mechanical, thermal,
and chemical threats. -
1:41 - 1:43If enough sensors are activated,
-
1:43 - 1:48electrical signals shoot up the nerve
to the spine and on to the brain. -
1:48 - 1:51The brain weighs the importance
of these signals -
1:51 - 1:55and produces pain if it decides
the body needs protection. -
1:55 - 1:59Typically, pain helps the body
avoid further injury or damage. -
1:59 - 2:03But there are a whole set of factors
besides nociception -
2:03 - 2:09that can influence the experience of pain—
and make pain less useful. -
2:09 - 2:14First, there are biological factors that
amplify nociceptive signals to the brain. -
2:14 - 2:17If nerve fibers are activated repeatedly,
-
2:17 - 2:20the brain may decide they need
to be more sensitive -
2:20 - 2:23to adequately protect the body
from threats. -
2:23 - 2:26More stress sensors can be
added to nerve fibers -
2:26 - 2:30until they become so sensitive that
even light touches to the skin -
2:30 - 2:33spark intense electrical signals.
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2:33 - 2:34In other cases,
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2:34 - 2:40nerves adapt to send signals more
efficiently, amplifying the message. -
2:40 - 2:41These forms of amplification
-
2:41 - 2:45are most common in people experiencing
chronic pain, -
2:45 - 2:49which is defined as pain lasting
more than 3 months. -
2:49 - 2:53When the nervous system is nudged
into an ongoing state of high alert, -
2:53 - 2:56pain can outlast physical injury.
-
2:56 - 3:00This creates a vicious cycle in which
the longer pain persists, -
3:00 - 3:03the more difficult it becomes to reverse.
-
3:03 - 3:07Psychological factors clearly
play a role in pain too, -
3:07 - 3:12potentially by influencing nociception and
by influencing the brain directly. -
3:12 - 3:15A person’s emotional state, memories,
-
3:15 - 3:18beliefs about pain and expectations
about treatment -
3:18 - 3:22can all influence how much
pain they experience. -
3:22 - 3:23In one study,
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3:23 - 3:27children who reported believing they
had no control over pain -
3:27 - 3:30actually experienced more intense pain
-
3:30 - 3:33than those who believed they
had some control. -
3:33 - 3:35Features of the environment matter too:
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3:35 - 3:36In one experiment,
-
3:36 - 3:41volunteers with a cold rod placed on
the back of their hand -
3:41 - 3:45reported feeling more pain when they were
shown a red light than a blue one, -
3:45 - 3:49even though the rod was the same
temperature each time. -
3:49 - 3:54Finally, social factors like the
availability of family support -
3:54 - 3:56can affect perception of pain.
-
3:56 - 3:59All of this means that a multi-pronged
approach to pain treatment -
3:59 - 4:05that includes pain specialists, physical
therapists, clinical psychologists, nurses -
4:05 - 4:09and other healthcare professionals
is often most effective. -
4:09 - 4:14We’re only beginning to uncover the
mechanisms behind the experience of pain, -
4:14 - 4:17but there are some promising
areas of research. -
4:17 - 4:18Until recently,
-
4:18 - 4:23we thought the glial cells surrounding
neurons were just support structures, -
4:23 - 4:27but now we know they have a huge role
in influencing nociception. -
4:27 - 4:32Studies have shown that disabling certain
brain circuits in the amygdala -
4:32 - 4:34can eliminate pain in rats.
-
4:34 - 4:37And genetic testing in people with
rare disorders -
4:37 - 4:39that prevent them from feeling pain
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4:39 - 4:43have pinpointed several other
possible targets for drugs -
4:43 - 4:46and perhaps eventually gene therapy.
- Title:
- The mysterious science of pain - Joshua W. Pate
- Speaker:
- Joshua W. Pate
- Description:
-
View full lesson: https://ed.ted.com/lessons/the-mysterious-science-of-pain-joshua-w-pate
In 1995, the British Medical Journal published a report about a builder who accidentally jumped onto a nail, which pierced straight through his steel-toed boot. He was in such agonizing pain that any movement was unbearable. But when the doctors took off his boot, they discovered that the nail had never touched his foot at all. What’s going on? Joshua W. Pate investigates the experience of pain.
Lesson by Joshua W. Pate, directed by Artrake Studio.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 04:47
Elise Haadsma approved English subtitles for The mysterious science of pain | ||
Elise Haadsma accepted English subtitles for The mysterious science of pain | ||
lauren mcalpine edited English subtitles for The mysterious science of pain | ||
lauren mcalpine edited English subtitles for The mysterious science of pain |