00:00:06 → 00:00:10 Let's say that it would take you ten minutes to solve this puzzle.

00:00:10 → 00:00:12 How long would it take

00:00:12 → 00:00:15 if you received constant electric shocks to your hands?

00:00:15 → 00:00:17 Longer, right?

00:00:17 → 00:00:19 Because the pain would distract you from the task.

00:00:19 → 00:00:21 Well, maybe not;

00:00:21 → 00:00:23 it depends on how you handle pain.

00:00:23 → 00:00:25 Some people are distracted by pain.

00:00:25 → 00:00:28 It takes them longer to complete a task, and they do it less well.

00:00:28 → 00:00:32 Other people use tasks to distract themselves from pain,

00:00:32 → 00:00:34 and those people actually do the task

00:00:34 → 00:00:37 faster and better when they're in pain

00:00:37 → 00:00:39 than when they're not.

00:00:39 → 00:00:41 Some people can just send their mind wandering

00:00:41 → 00:00:43 to distract themselves from pain.

00:00:43 → 00:00:45 How can different people

00:00:45 → 00:00:47 be subjected to the exact same painful stimulus

00:00:47 → 00:00:51 and yet experience the pain so differently?

00:00:51 → 00:00:52 And why does this matter?

00:00:52 → 00:00:54 First of all, what is pain?

00:00:54 → 00:00:58 Pain is an unpleasant sensory and emotional experience,

00:00:58 → 00:01:02 associated with actual or potential tissue damage.

00:01:02 → 00:01:03 Pain is something we experience,

00:01:03 → 00:01:06 so it's best measured by what you say it is.

00:01:06 → 00:01:08 Pain has an intensity;

00:01:08 → 00:01:09 you can describe it on a scale

00:01:09 → 00:01:13 from zero, no pain, to ten, the most pain imaginable.

00:01:14 → 00:01:16 But pain also has a character,

00:01:16 → 00:01:20 like sharp, dull, burning, or aching.

00:01:20 → 00:01:23 What exactly creates these perceptions of pain?

00:01:24 → 00:01:25 Well, when you get hurt,

00:01:25 → 00:01:28 special tissue damage-sensing nerve cells,

00:01:28 → 00:01:31 called nociceptors, fire and send signals

00:01:31 → 00:01:34 to the spinal cord and then up to the brain.

00:01:34 → 00:01:38 Processing work gets done by cells called neurons and glia.

00:01:38 → 00:01:40 This is your Grey matter.

00:01:40 → 00:01:44 And brain superhighways carry information as electrical impulses

00:01:44 → 00:01:46 from one area to another.

00:01:46 → 00:01:48 This is your white matter.

00:01:48 → 00:01:51 The superhighway that carries pain information

00:01:51 → 00:01:53 from the spinal cord to the brain

00:01:53 → 00:01:55 is our sensing pathway

00:01:55 → 00:01:56 that ends in the cortex,

00:01:56 → 00:01:59 a part of the brain that decides what to do

00:01:59 → 00:02:00 with the pain signal.

00:02:01 → 00:02:03 Another system of interconnected brain cells

00:02:03 → 00:02:05 called the salience network

00:02:05 → 00:02:07 decides what to pay attention to.

00:02:07 → 00:02:09 Since pain can have serious consequences,

00:02:09 → 00:02:13 the pain signal immediately activates the salience network.

00:02:14 → 00:02:16 Now, you're paying attention.

00:02:16 → 00:02:18 The brain also responds to the pain

00:02:18 → 00:02:21 and has to cope with these pain signals.

00:02:21 → 00:02:23 So, motor pathways are activated

00:02:23 → 00:02:25 to take your hand off a hot stove, for example.

00:02:26 → 00:02:29 But modulation networks are also activated

00:02:29 → 00:02:32 that deliver endorphins and enkephalins,

00:02:32 → 00:02:35 chemicals released when you're in pain or during extreme exercise,

00:02:35 → 00:02:37 creating the runner's high.

00:02:37 → 00:02:41 These chemical systems help regulate and reduce pain.

00:02:42 → 00:02:44 All these networks and pathways work together

00:02:44 → 00:02:46 to create your pain experience,

00:02:46 → 00:02:48 to prevent further tissue damage,

00:02:48 → 00:02:50 and help you to cope with pain.

00:02:50 → 00:02:52 This system is similar for everyone,

00:02:52 → 00:02:56 but the sensitivity and efficacy of these brain circuits

00:02:56 → 00:02:59 determines how much you feel and cope with pain.

00:02:59 → 00:03:02 This is why some people have greater pain than others

00:03:02 → 00:03:04 and why some develop chronic pain

00:03:04 → 00:03:06 that does not respond to treatment,

00:03:06 → 00:03:08 while others respond well.

00:03:08 → 00:03:10 Variability in pain sensitivities

00:03:10 → 00:03:13 is not so different than all kinds of variability

00:03:13 → 00:03:14 in responses to other stimuli.

00:03:15 → 00:03:17 Like how some people love roller coasters,

00:03:17 → 00:03:20 but other people suffer from terrible motion sickness.

00:03:20 → 00:03:23 Why does it matter that there is variability

00:03:23 → 00:03:24 in our pain brain circuits?

00:03:24 → 00:03:27 Well, there are many treatments for pain,

00:03:27 → 00:03:28 targeting different systems.

00:03:28 → 00:03:31 For mild pain, non-prescription medications

00:03:31 → 00:03:34 can act on cells where the pain signals start.

00:03:34 → 00:03:36 Other stronger pain medicines and anesthetics

00:03:36 → 00:03:40 work by reducing the activity in pain-sensing circuits

00:03:40 → 00:03:44 or boosting our coping system, or endorphins.

00:03:44 → 00:03:47 Some people can cope with pain using methods that involve

00:03:47 → 00:03:50 distraction, relaxation, meditation, yoga,

00:03:50 → 00:03:54 or strategies that can be taught, like cognitive behavioral therapy.

00:03:55 → 00:03:57 For some people who suffer from severe chronic pain,

00:03:57 → 00:03:59 that is pain that doesn't go away

00:03:59 → 00:04:01 months after their injury should have healed,

00:04:01 → 00:04:03 none of the regular treatments work.

00:04:03 → 00:04:06 Traditionally, medical science has been about

00:04:06 → 00:04:08 testing treatments on large groups

00:04:08 → 00:04:11 to determine what would help a majority of patients.

00:04:11 → 00:04:12 But this has usually left out

00:04:12 → 00:04:14 some who didn't benefit from the treatment

00:04:14 → 00:04:16 or experienced side effects.

00:04:16 → 00:04:20 Now, new treatments that directly stimulate or block

00:04:20 → 00:04:24 certain pain-sensing attention or modulation networks

00:04:24 → 00:04:25 are being developed,

00:04:25 → 00:04:29 along with ways to tailor them to individual patients,

00:04:29 → 00:04:31 using tools like magnetic resonance imaging

00:04:31 → 00:04:33 to map brain pathways.

00:04:34 → 00:04:36 Figuring out how your brain responds to pain

00:04:36 → 00:04:39 is the key to finding the best treatment for you.

00:04:39 → 00:04:41 That's true personalized medicine.