[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.68,0:00:05.29,Default,,0000,0000,0000,,Memory is such an everyday thing\Nthat we almost take it for granted.
Dialogue: 0,0:00:05.67,0:00:08.28,Default,,0000,0000,0000,,We all remember what we had\Nfor breakfast this morning
Dialogue: 0,0:00:08.31,0:00:09.89,Default,,0000,0000,0000,,or what we did last weekend.
Dialogue: 0,0:00:09.92,0:00:11.97,Default,,0000,0000,0000,,It's only when memory starts to fail
Dialogue: 0,0:00:11.99,0:00:14.66,Default,,0000,0000,0000,,that we appreciate just how amazing it is
Dialogue: 0,0:00:14.68,0:00:18.14,Default,,0000,0000,0000,,and how much we allow\Nour past experiences to define us.
Dialogue: 0,0:00:19.60,0:00:22.45,Default,,0000,0000,0000,,But memory is not always a good thing.
Dialogue: 0,0:00:23.08,0:00:26.85,Default,,0000,0000,0000,,As the American poet and clergyman\NJohn Lancaster Spalding once said,
Dialogue: 0,0:00:26.88,0:00:30.03,Default,,0000,0000,0000,,"As memory may be a paradise\Nfrom which we cannot be driven,
Dialogue: 0,0:00:30.06,0:00:33.48,Default,,0000,0000,0000,,it may also be a hell\Nfrom which we cannot escape."
Dialogue: 0,0:00:34.82,0:00:37.49,Default,,0000,0000,0000,,Many of us experience\Nchapters of our lives
Dialogue: 0,0:00:37.51,0:00:39.95,Default,,0000,0000,0000,,that we would prefer\Nto never have happened.
Dialogue: 0,0:00:40.36,0:00:42.90,Default,,0000,0000,0000,,It is estimated that\Nnearly 90 percent of us
Dialogue: 0,0:00:42.93,0:00:46.80,Default,,0000,0000,0000,,will experience some sort of\Ntraumatic event during our lifetimes.
Dialogue: 0,0:00:47.70,0:00:52.53,Default,,0000,0000,0000,,Many of us will suffer acutely\Nfollowing these events and then recover,
Dialogue: 0,0:00:52.55,0:00:56.00,Default,,0000,0000,0000,,maybe even become better people\Nbecause of those experiences.
Dialogue: 0,0:00:56.88,0:01:01.02,Default,,0000,0000,0000,,But some events\Nare so extreme that many --
Dialogue: 0,0:01:01.04,0:01:04.80,Default,,0000,0000,0000,,up to half of those who survive\Nsexual violence, for example --
Dialogue: 0,0:01:04.82,0:01:07.92,Default,,0000,0000,0000,,will go on to develop\Npost-traumatic stress disorder,
Dialogue: 0,0:01:07.94,0:01:09.30,Default,,0000,0000,0000,,or PTSD.
Dialogue: 0,0:01:10.67,0:01:13.96,Default,,0000,0000,0000,,PTSD is a debilitating\Nmental health condition
Dialogue: 0,0:01:13.98,0:01:18.30,Default,,0000,0000,0000,,characterized by symptoms\Nsuch as intense fear and anxiety
Dialogue: 0,0:01:18.32,0:01:20.90,Default,,0000,0000,0000,,and flashbacks of the traumatic event.
Dialogue: 0,0:01:21.81,0:01:26.04,Default,,0000,0000,0000,,These symptoms have a huge impact\Non a person's quality of life
Dialogue: 0,0:01:26.07,0:01:28.90,Default,,0000,0000,0000,,and are often triggered\Nby particular situations
Dialogue: 0,0:01:28.93,0:01:31.71,Default,,0000,0000,0000,,or cues in that person's environment.
Dialogue: 0,0:01:32.62,0:01:37.59,Default,,0000,0000,0000,,The responses to those cues may have been\Nadaptive when they were first learned --
Dialogue: 0,0:01:37.62,0:01:41.26,Default,,0000,0000,0000,,fear and diving for cover\Nin a war zone, for example --
Dialogue: 0,0:01:41.28,0:01:42.45,Default,,0000,0000,0000,,but in PTSD,
Dialogue: 0,0:01:42.47,0:01:45.98,Default,,0000,0000,0000,,they continue to control behavior\Nwhen it's no longer appropriate.
Dialogue: 0,0:01:46.76,0:01:50.10,Default,,0000,0000,0000,,If a combat veteran returns home\Nand is diving for cover
Dialogue: 0,0:01:50.12,0:01:52.23,Default,,0000,0000,0000,,when he or she hears a car backfiring
Dialogue: 0,0:01:52.26,0:01:56.17,Default,,0000,0000,0000,,or can't leave their own home\Nbecause of intense anxiety,
Dialogue: 0,0:01:56.20,0:02:00.12,Default,,0000,0000,0000,,then the responses\Nto those cues, those memories,
Dialogue: 0,0:02:00.14,0:02:03.92,Default,,0000,0000,0000,,have become what we would\Nrefer to as maladaptive.
Dialogue: 0,0:02:04.57,0:02:10.74,Default,,0000,0000,0000,,In this way, we can think of PTSD\Nas being a disorder of maladaptive memory.
Dialogue: 0,0:02:12.61,0:02:14.18,Default,,0000,0000,0000,,Now, I should stop myself here,
Dialogue: 0,0:02:14.21,0:02:17.43,Default,,0000,0000,0000,,because I'm talking about memory\Nas if it's a single thing.
Dialogue: 0,0:02:17.45,0:02:18.64,Default,,0000,0000,0000,,It isn't.
Dialogue: 0,0:02:19.14,0:02:21.12,Default,,0000,0000,0000,,There are many different types of memory,
Dialogue: 0,0:02:21.14,0:02:25.24,Default,,0000,0000,0000,,and these depend upon different circuits\Nand regions within the brain.
Dialogue: 0,0:02:26.18,0:02:31.11,Default,,0000,0000,0000,,As you can see, there are two\Nmajor distinctions in our types of memory.
Dialogue: 0,0:02:31.62,0:02:34.34,Default,,0000,0000,0000,,There are those memories\Nthat we're consciously aware of,
Dialogue: 0,0:02:34.37,0:02:35.53,Default,,0000,0000,0000,,where we know we know
Dialogue: 0,0:02:35.55,0:02:37.30,Default,,0000,0000,0000,,and that we can pass on in words.
Dialogue: 0,0:02:37.69,0:02:40.35,Default,,0000,0000,0000,,This would include memories\Nfor facts and events.
Dialogue: 0,0:02:40.90,0:02:43.12,Default,,0000,0000,0000,,Because we can declare these memories,
Dialogue: 0,0:02:43.14,0:02:45.69,Default,,0000,0000,0000,,we refer to these as declarative memories.
Dialogue: 0,0:02:46.97,0:02:49.88,Default,,0000,0000,0000,,The other type of memory\Nis non-declarative.
Dialogue: 0,0:02:50.47,0:02:53.88,Default,,0000,0000,0000,,These are memories where we often\Ndon't have conscious access
Dialogue: 0,0:02:53.90,0:02:55.61,Default,,0000,0000,0000,,to the content of those memories
Dialogue: 0,0:02:55.63,0:02:57.57,Default,,0000,0000,0000,,and that we can't pass on in words.
Dialogue: 0,0:02:58.60,0:03:01.20,Default,,0000,0000,0000,,The classic example\Nof a non-declarative memory
Dialogue: 0,0:03:01.22,0:03:03.70,Default,,0000,0000,0000,,is the motor skill for riding a bike.
Dialogue: 0,0:03:04.30,0:03:07.61,Default,,0000,0000,0000,,Now, this being Cambridge,\Nthe odds are that you can ride a bike.
Dialogue: 0,0:03:07.63,0:03:09.68,Default,,0000,0000,0000,,You know what you're doing on two wheels.
Dialogue: 0,0:03:10.38,0:03:13.40,Default,,0000,0000,0000,,But if I asked you to write me\Na list of instructions
Dialogue: 0,0:03:13.43,0:03:15.66,Default,,0000,0000,0000,,that would teach me how to ride a bike,
Dialogue: 0,0:03:15.69,0:03:18.25,Default,,0000,0000,0000,,as my four-year-old son did\Nwhen we bought him a bike
Dialogue: 0,0:03:18.28,0:03:19.80,Default,,0000,0000,0000,,for his last birthday,
Dialogue: 0,0:03:19.83,0:03:22.32,Default,,0000,0000,0000,,you would really struggle to do that.
Dialogue: 0,0:03:23.14,0:03:25.64,Default,,0000,0000,0000,,How should you sit on the bike\Nso you're balanced?
Dialogue: 0,0:03:25.66,0:03:28.14,Default,,0000,0000,0000,,How fast do you need to pedal\Nso you're stable?
Dialogue: 0,0:03:28.52,0:03:30.56,Default,,0000,0000,0000,,If a gust of wind comes at you,
Dialogue: 0,0:03:30.59,0:03:33.37,Default,,0000,0000,0000,,which muscles should you tense\Nand by how much
Dialogue: 0,0:03:33.40,0:03:35.42,Default,,0000,0000,0000,,so that you don't get blown off?
Dialogue: 0,0:03:36.45,0:03:39.65,Default,,0000,0000,0000,,I'll be staggered if you can give\Nthe answers to those questions.
Dialogue: 0,0:03:39.67,0:03:43.35,Default,,0000,0000,0000,,But if you can ride a bike,\Nyou do have the answers,
Dialogue: 0,0:03:43.38,0:03:45.76,Default,,0000,0000,0000,,you're just not consciously aware of them.
Dialogue: 0,0:03:48.89,0:03:50.42,Default,,0000,0000,0000,,Getting back to PTSD,
Dialogue: 0,0:03:50.45,0:03:53.11,Default,,0000,0000,0000,,another type of non-declarative memory
Dialogue: 0,0:03:53.14,0:03:55.10,Default,,0000,0000,0000,,is emotional memory.
Dialogue: 0,0:03:55.12,0:03:57.53,Default,,0000,0000,0000,,Now, this has a specific\Nmeaning in psychology
Dialogue: 0,0:03:57.56,0:04:01.04,Default,,0000,0000,0000,,and refers to our ability\Nto learn about cues in our environment
Dialogue: 0,0:04:01.06,0:04:04.01,Default,,0000,0000,0000,,and their emotional\Nand motivational significance.
Dialogue: 0,0:04:04.67,0:04:05.95,Default,,0000,0000,0000,,What do I mean by that?
Dialogue: 0,0:04:06.37,0:04:10.73,Default,,0000,0000,0000,,Well, think of a cue\Nlike the smell of baking bread,
Dialogue: 0,0:04:10.76,0:04:13.50,Default,,0000,0000,0000,,or a more abstract cue\Nlike a 20-pound note.
Dialogue: 0,0:04:13.96,0:04:17.25,Default,,0000,0000,0000,,Because these cues have been pegged\Nwith good things in the past,
Dialogue: 0,0:04:17.27,0:04:19.19,Default,,0000,0000,0000,,we like them and we approach them.
Dialogue: 0,0:04:19.93,0:04:24.81,Default,,0000,0000,0000,,Other cues, like the buzzing of a wasp,\Nelicit very negative emotions
Dialogue: 0,0:04:24.84,0:04:28.63,Default,,0000,0000,0000,,and quite dramatic\Navoidance behavior in some people.
Dialogue: 0,0:04:29.62,0:04:32.27,Default,,0000,0000,0000,,Now, I hate wasps.
Dialogue: 0,0:04:32.29,0:04:33.80,Default,,0000,0000,0000,,I can tell you that fact.
Dialogue: 0,0:04:33.83,0:04:37.41,Default,,0000,0000,0000,,But what I can't give you\Nare the non-declarative emotional memories
Dialogue: 0,0:04:37.43,0:04:39.71,Default,,0000,0000,0000,,for how I react\Nwhen there's a wasp nearby.
Dialogue: 0,0:04:40.17,0:04:42.33,Default,,0000,0000,0000,,I can't give you the racing heart,
Dialogue: 0,0:04:42.36,0:04:45.87,Default,,0000,0000,0000,,the sweaty palms,\Nthat sense of rising panic.
Dialogue: 0,0:04:45.89,0:04:48.06,Default,,0000,0000,0000,,I can describe them to you,
Dialogue: 0,0:04:48.08,0:04:50.36,Default,,0000,0000,0000,,but I can't give them to you.
Dialogue: 0,0:04:52.36,0:04:55.27,Default,,0000,0000,0000,,Now, importantly,\Nfrom the perspective of PTSD,
Dialogue: 0,0:04:55.29,0:05:00.06,Default,,0000,0000,0000,,stress has very different effects on\Ndeclarative and non-declarative memories
Dialogue: 0,0:05:00.08,0:05:02.81,Default,,0000,0000,0000,,and the brain circuits\Nand regions supporting them.
Dialogue: 0,0:05:03.46,0:05:06.84,Default,,0000,0000,0000,,Emotional memory is supported\Nby a small almond-shaped structure
Dialogue: 0,0:05:06.86,0:05:08.02,Default,,0000,0000,0000,,called the amygdala
Dialogue: 0,0:05:08.05,0:05:09.28,Default,,0000,0000,0000,,and its connections.
Dialogue: 0,0:05:09.88,0:05:14.38,Default,,0000,0000,0000,,Declarative memory, especially the what,\Nwhere and when of event memory,
Dialogue: 0,0:05:14.40,0:05:16.98,Default,,0000,0000,0000,,is supported by a seahorse-shaped\Nregion of the brain
Dialogue: 0,0:05:17.00,0:05:18.49,Default,,0000,0000,0000,,called the hippocampus.
Dialogue: 0,0:05:19.35,0:05:22.49,Default,,0000,0000,0000,,The extreme levels of stress\Nexperienced during trauma
Dialogue: 0,0:05:22.51,0:05:25.85,Default,,0000,0000,0000,,have very different effects\Non these two structures.
Dialogue: 0,0:05:26.79,0:05:30.04,Default,,0000,0000,0000,,As you can see, as you increase\Na person's level of stress
Dialogue: 0,0:05:30.06,0:05:32.10,Default,,0000,0000,0000,,from not stressful to slightly stressful,
Dialogue: 0,0:05:32.13,0:05:33.38,Default,,0000,0000,0000,,the hippocampus,
Dialogue: 0,0:05:33.40,0:05:35.60,Default,,0000,0000,0000,,acting to support the event memory,
Dialogue: 0,0:05:35.63,0:05:37.29,Default,,0000,0000,0000,,increases in its activity
Dialogue: 0,0:05:37.31,0:05:40.59,Default,,0000,0000,0000,,and works better to support\Nthe storage of that declarative memory.
Dialogue: 0,0:05:41.37,0:05:45.00,Default,,0000,0000,0000,,But as you increase to moderately\Nstressful, intensely stressful
Dialogue: 0,0:05:45.02,0:05:48.62,Default,,0000,0000,0000,,and then extremely stressful,\Nas would be found in trauma,
Dialogue: 0,0:05:48.64,0:05:52.32,Default,,0000,0000,0000,,the hippocampus\Neffectively shuts down.
Dialogue: 0,0:05:53.36,0:05:56.15,Default,,0000,0000,0000,,This means that under\Nthe high levels of stress hormones
Dialogue: 0,0:05:56.17,0:05:58.19,Default,,0000,0000,0000,,that are experienced\Nduring trauma,
Dialogue: 0,0:05:58.22,0:06:00.24,Default,,0000,0000,0000,,we are not storing the details,
Dialogue: 0,0:06:00.26,0:06:03.99,Default,,0000,0000,0000,,the specific details\Nof what, where and when.
Dialogue: 0,0:06:05.37,0:06:07.78,Default,,0000,0000,0000,,Now, while stress is doing that\Nto the hippocampus,
Dialogue: 0,0:06:07.81,0:06:09.64,Default,,0000,0000,0000,,look at what it does to the amygdala,
Dialogue: 0,0:06:09.66,0:06:13.08,Default,,0000,0000,0000,,that structure important\Nfor the emotional, non-declarative memory.
Dialogue: 0,0:06:13.10,0:06:16.29,Default,,0000,0000,0000,,Its activity gets stronger and stronger.
Dialogue: 0,0:06:17.67,0:06:20.21,Default,,0000,0000,0000,,So what this leaves\Nus with in PTSD
Dialogue: 0,0:06:20.23,0:06:24.17,Default,,0000,0000,0000,,is an overly strong emotional --\Nin this case fear -- memory
Dialogue: 0,0:06:24.20,0:06:27.11,Default,,0000,0000,0000,,that is not tied\Nto a specific time or place,
Dialogue: 0,0:06:27.14,0:06:31.80,Default,,0000,0000,0000,,because the hippocampus\Nis not storing what, where and when.
Dialogue: 0,0:06:32.44,0:06:35.54,Default,,0000,0000,0000,,In this way, these cues\Ncan control behavior
Dialogue: 0,0:06:35.56,0:06:37.67,Default,,0000,0000,0000,,when it's no longer appropriate,
Dialogue: 0,0:06:37.69,0:06:40.38,Default,,0000,0000,0000,,and that's how\Nthey become maladaptive.
Dialogue: 0,0:06:40.81,0:06:46.62,Default,,0000,0000,0000,,So if we know that PTSD\Nis due to maladaptive memories,
Dialogue: 0,0:06:46.64,0:06:49.88,Default,,0000,0000,0000,,can we use that knowledge\Nto improve treatment outcomes
Dialogue: 0,0:06:49.91,0:06:51.66,Default,,0000,0000,0000,,for patients with PTSD?
Dialogue: 0,0:06:53.51,0:06:58.31,Default,,0000,0000,0000,,A radical new approach being developed\Nto treat post-traumatic stress disorder
Dialogue: 0,0:06:58.34,0:07:01.90,Default,,0000,0000,0000,,aims to destroy those maladaptive\Nemotional memories
Dialogue: 0,0:07:01.92,0:07:03.64,Default,,0000,0000,0000,,that underlie the disorder.
Dialogue: 0,0:07:04.34,0:07:07.01,Default,,0000,0000,0000,,This approach has only\Nbeen considered a possibility
Dialogue: 0,0:07:07.04,0:07:10.32,Default,,0000,0000,0000,,because of the profound changes\Nin our understanding of memory
Dialogue: 0,0:07:10.34,0:07:11.76,Default,,0000,0000,0000,,in recent years.
Dialogue: 0,0:07:12.58,0:07:15.03,Default,,0000,0000,0000,,Traditionally, it was thought\Nthat making a memory
Dialogue: 0,0:07:15.05,0:07:17.69,Default,,0000,0000,0000,,was like writing in a notebook in pen:
Dialogue: 0,0:07:17.72,0:07:21.20,Default,,0000,0000,0000,,once the ink had dried,\Nyou couldn't change the information.
Dialogue: 0,0:07:21.66,0:07:23.95,Default,,0000,0000,0000,,It was thought that all\Nthose structural changes
Dialogue: 0,0:07:23.97,0:07:26.68,Default,,0000,0000,0000,,that happen in the brain\Nto support the storage of memory
Dialogue: 0,0:07:26.70,0:07:28.55,Default,,0000,0000,0000,,were finished within about six hours,
Dialogue: 0,0:07:28.58,0:07:30.64,Default,,0000,0000,0000,,and after that, they were permanent.
Dialogue: 0,0:07:31.06,0:07:33.78,Default,,0000,0000,0000,,This is known as the consolidation view.
Dialogue: 0,0:07:35.08,0:07:38.11,Default,,0000,0000,0000,,However, more recent research suggests\Nthat making a memory
Dialogue: 0,0:07:38.14,0:07:41.41,Default,,0000,0000,0000,,is actually more like writing\Nin a word processor.
Dialogue: 0,0:07:41.89,0:07:45.52,Default,,0000,0000,0000,,We initially make the memory\Nand then we save it or store it.
Dialogue: 0,0:07:45.54,0:07:49.30,Default,,0000,0000,0000,,But under the right conditions,\Nwe can edit that memory.
Dialogue: 0,0:07:50.23,0:07:53.91,Default,,0000,0000,0000,,This reconsolidation view suggests\Nthat those structural changes
Dialogue: 0,0:07:53.94,0:07:56.33,Default,,0000,0000,0000,,that happen in the brain to support memory
Dialogue: 0,0:07:56.36,0:07:57.99,Default,,0000,0000,0000,,can be undone,
Dialogue: 0,0:07:58.01,0:08:00.45,Default,,0000,0000,0000,,even for old memories.
Dialogue: 0,0:08:02.30,0:08:05.69,Default,,0000,0000,0000,,Now, this editing process\Nisn't happening all the time.
Dialogue: 0,0:08:05.71,0:08:08.70,Default,,0000,0000,0000,,It only happens under\Nvery specific conditions
Dialogue: 0,0:08:08.73,0:08:10.43,Default,,0000,0000,0000,,of memory retrieval.
Dialogue: 0,0:08:11.23,0:08:14.87,Default,,0000,0000,0000,,So let's consider memory retrieval\Nas being recalling the memory
Dialogue: 0,0:08:14.89,0:08:17.04,Default,,0000,0000,0000,,or, like, opening the file.
Dialogue: 0,0:08:18.08,0:08:20.61,Default,,0000,0000,0000,,Quite often, we are simply\Nretrieving the memory.
Dialogue: 0,0:08:20.64,0:08:23.16,Default,,0000,0000,0000,,We're opening the file as read-only.
Dialogue: 0,0:08:23.83,0:08:25.73,Default,,0000,0000,0000,,But under the right conditions,
Dialogue: 0,0:08:25.76,0:08:28.07,Default,,0000,0000,0000,,we can open that file in edit mode,
Dialogue: 0,0:08:28.09,0:08:30.31,Default,,0000,0000,0000,,and then we can change the information.
Dialogue: 0,0:08:30.33,0:08:34.30,Default,,0000,0000,0000,,In theory, we could delete\Nthe content of that file,
Dialogue: 0,0:08:34.32,0:08:36.04,Default,,0000,0000,0000,,and when we press save,
Dialogue: 0,0:08:36.06,0:08:39.88,Default,,0000,0000,0000,,that is how the file -- the memory --
Dialogue: 0,0:08:39.90,0:08:41.15,Default,,0000,0000,0000,,persists.
Dialogue: 0,0:08:43.13,0:08:45.38,Default,,0000,0000,0000,,Not only does this reconsolidation view
Dialogue: 0,0:08:45.40,0:08:48.51,Default,,0000,0000,0000,,allow us to account for some\Nof the quirks of memory,
Dialogue: 0,0:08:48.53,0:08:51.72,Default,,0000,0000,0000,,like how we all sometimes\Nmisremember the past,
Dialogue: 0,0:08:51.74,0:08:56.07,Default,,0000,0000,0000,,it also gives us a way to destroy\Nthose maladaptive fear memories
Dialogue: 0,0:08:56.10,0:08:57.92,Default,,0000,0000,0000,,that underlie PTSD.
Dialogue: 0,0:08:58.49,0:09:01.12,Default,,0000,0000,0000,,All we would need would be two things:
Dialogue: 0,0:09:01.14,0:09:06.19,Default,,0000,0000,0000,,a way of making the memory unstable --\Nopening that file in edit mode --
Dialogue: 0,0:09:06.21,0:09:08.57,Default,,0000,0000,0000,,and a way to delete the information.
Dialogue: 0,0:09:09.33,0:09:10.88,Default,,0000,0000,0000,,We've made the most progress
Dialogue: 0,0:09:10.90,0:09:13.44,Default,,0000,0000,0000,,with working out\Nhow to delete the information.
Dialogue: 0,0:09:13.86,0:09:15.65,Default,,0000,0000,0000,,It was found fairly early on
Dialogue: 0,0:09:15.67,0:09:19.51,Default,,0000,0000,0000,,that a drug widely prescribed\Nto control blood pressure in humans --
Dialogue: 0,0:09:19.54,0:09:21.65,Default,,0000,0000,0000,,a beta-blocker\Ncalled Propranolol --
Dialogue: 0,0:09:21.68,0:09:24.36,Default,,0000,0000,0000,,could be used to prevent\Nthe reconsolidation
Dialogue: 0,0:09:24.38,0:09:26.09,Default,,0000,0000,0000,,of fear memories in rats.
Dialogue: 0,0:09:27.00,0:09:30.77,Default,,0000,0000,0000,,If Propranolol was given\Nwhile the memory was in edit mode,
Dialogue: 0,0:09:30.80,0:09:35.14,Default,,0000,0000,0000,,rats behaved as if they were no longer\Nafraid of a frightening trigger cue.
Dialogue: 0,0:09:35.56,0:09:39.92,Default,,0000,0000,0000,,It was as if they had never learned\Nto be afraid of that cue.
Dialogue: 0,0:09:40.26,0:09:43.92,Default,,0000,0000,0000,,And this was with a drug\Nthat was safe for use in humans.
Dialogue: 0,0:09:44.96,0:09:46.26,Default,,0000,0000,0000,,Now, not long after that,
Dialogue: 0,0:09:46.28,0:09:50.31,Default,,0000,0000,0000,,it was shown that Propranolol could\Ndestroy fear memories in humans as well,
Dialogue: 0,0:09:50.33,0:09:54.99,Default,,0000,0000,0000,,but critically, it only works\Nif the memory is in edit mode.
Dialogue: 0,0:09:56.17,0:09:58.58,Default,,0000,0000,0000,,Now, that study was with\Nhealthy human volunteers,
Dialogue: 0,0:09:58.61,0:10:01.83,Default,,0000,0000,0000,,but it's important because it shows\Nthat the rat findings
Dialogue: 0,0:10:01.86,0:10:06.09,Default,,0000,0000,0000,,can be extended to humans\Nand ultimately, to human patients.
Dialogue: 0,0:10:07.33,0:10:09.28,Default,,0000,0000,0000,,And with humans,
Dialogue: 0,0:10:09.30,0:10:13.96,Default,,0000,0000,0000,,you can test whether destroying\Nthe non-declarative emotional memory
Dialogue: 0,0:10:13.98,0:10:16.90,Default,,0000,0000,0000,,does anything to\Nthe declarative event memory.
Dialogue: 0,0:10:17.56,0:10:19.94,Default,,0000,0000,0000,,And this is really interesting.
Dialogue: 0,0:10:19.96,0:10:22.59,Default,,0000,0000,0000,,Even though people\Nwho were given Propranolol
Dialogue: 0,0:10:22.61,0:10:24.22,Default,,0000,0000,0000,,while the memory was in edit mode
Dialogue: 0,0:10:24.24,0:10:27.97,Default,,0000,0000,0000,,were no longer afraid\Nof that frightening trigger cue,
Dialogue: 0,0:10:27.99,0:10:30.47,Default,,0000,0000,0000,,they could still describe the relationship
Dialogue: 0,0:10:30.50,0:10:34.20,Default,,0000,0000,0000,,between the cue\Nand the frightening outcome.
Dialogue: 0,0:10:35.14,0:10:38.72,Default,,0000,0000,0000,,It was as if they knew\Nthey should be afraid,
Dialogue: 0,0:10:39.65,0:10:41.06,Default,,0000,0000,0000,,and yet they weren't.
Dialogue: 0,0:10:42.03,0:10:45.42,Default,,0000,0000,0000,,This suggests that Propranolol\Ncan selectively target
Dialogue: 0,0:10:45.45,0:10:47.98,Default,,0000,0000,0000,,the non-declarative emotional memory
Dialogue: 0,0:10:48.01,0:10:51.69,Default,,0000,0000,0000,,but leave the declarative\Nevent memory intact.
Dialogue: 0,0:10:52.05,0:10:56.46,Default,,0000,0000,0000,,But critically, Propranolol can only have\Nany effect on the memory
Dialogue: 0,0:10:56.48,0:10:58.32,Default,,0000,0000,0000,,if it's in edit mode.
Dialogue: 0,0:10:59.02,0:11:01.09,Default,,0000,0000,0000,,So how do we make a memory unstable?
Dialogue: 0,0:11:01.11,0:11:03.19,Default,,0000,0000,0000,,How do we get it into edit mode?
Dialogue: 0,0:11:03.64,0:11:06.46,Default,,0000,0000,0000,,Well, my own lab has done\Nquite a lot of work on this.
Dialogue: 0,0:11:06.48,0:11:11.28,Default,,0000,0000,0000,,We know that it depends on introducing\Nsome but not too much new information
Dialogue: 0,0:11:11.31,0:11:13.57,Default,,0000,0000,0000,,to be incorporated into the memory.
Dialogue: 0,0:11:13.59,0:11:16.12,Default,,0000,0000,0000,,We know about the different\Nchemicals the brain uses
Dialogue: 0,0:11:16.15,0:11:18.64,Default,,0000,0000,0000,,to signal that a memory\Nshould be updated
Dialogue: 0,0:11:18.67,0:11:20.53,Default,,0000,0000,0000,,and the file edited.
Dialogue: 0,0:11:21.31,0:11:23.51,Default,,0000,0000,0000,,Now, our work is mostly in rats,
Dialogue: 0,0:11:23.54,0:11:28.28,Default,,0000,0000,0000,,but other labs have found the same factors\Nallow memories to be edited in humans,
Dialogue: 0,0:11:28.30,0:11:32.90,Default,,0000,0000,0000,,even maladaptive memories\Nlike those underlying PTSD.
Dialogue: 0,0:11:33.40,0:11:36.16,Default,,0000,0000,0000,,In fact, a number of labs\Nin several different countries
Dialogue: 0,0:11:36.18,0:11:40.66,Default,,0000,0000,0000,,have begun small-scale clinical trials\Nof these memory-destroying treatments
Dialogue: 0,0:11:40.69,0:11:41.98,Default,,0000,0000,0000,,for PTSD
Dialogue: 0,0:11:42.00,0:11:44.68,Default,,0000,0000,0000,,and have found really promising results.
Dialogue: 0,0:11:45.83,0:11:49.26,Default,,0000,0000,0000,,Now, these studies need replication\Non a larger scale,
Dialogue: 0,0:11:49.29,0:11:52.74,Default,,0000,0000,0000,,but they show the promise\Nof these memory-destroying treatments
Dialogue: 0,0:11:52.76,0:11:54.74,Default,,0000,0000,0000,,for PTSD.
Dialogue: 0,0:11:54.77,0:12:00.32,Default,,0000,0000,0000,,Maybe trauma memories do not need to be\Nthe hell from which we cannot escape.
Dialogue: 0,0:12:02.62,0:12:05.83,Default,,0000,0000,0000,,Now, although this memory-destroying\Napproach holds great promise,
Dialogue: 0,0:12:05.85,0:12:08.40,Default,,0000,0000,0000,,that's not to say\Nthat it's straightforward
Dialogue: 0,0:12:08.43,0:12:10.51,Default,,0000,0000,0000,,or without controversy.
Dialogue: 0,0:12:10.54,0:12:12.73,Default,,0000,0000,0000,,Is it ethical to destroy memories?
Dialogue: 0,0:12:12.75,0:12:14.97,Default,,0000,0000,0000,,What about things\Nlike eyewitness testimony?
Dialogue: 0,0:12:15.49,0:12:17.67,Default,,0000,0000,0000,,What if you can't give someone Propranolol
Dialogue: 0,0:12:17.70,0:12:20.96,Default,,0000,0000,0000,,because it would interfere\Nwith other medicines that they're taking?
Dialogue: 0,0:12:21.80,0:12:24.40,Default,,0000,0000,0000,,Well, with respect to ethics\Nand eyewitness testimony,
Dialogue: 0,0:12:24.42,0:12:26.46,Default,,0000,0000,0000,,I would say the important\Npoint to remember
Dialogue: 0,0:12:26.48,0:12:28.78,Default,,0000,0000,0000,,is the finding from that human study.
Dialogue: 0,0:12:29.90,0:12:34.18,Default,,0000,0000,0000,,Because Propranolol is only acting\Non the non-declarative emotional memory,
Dialogue: 0,0:12:34.20,0:12:37.65,Default,,0000,0000,0000,,it seems unlikely that it would affect\Neyewitness testimony,
Dialogue: 0,0:12:37.68,0:12:40.07,Default,,0000,0000,0000,,which is based on declarative memory.
Dialogue: 0,0:12:40.96,0:12:43.44,Default,,0000,0000,0000,,Essentially, what these\Nmemory-destroying treatments
Dialogue: 0,0:12:43.47,0:12:44.64,Default,,0000,0000,0000,,are aiming to do
Dialogue: 0,0:12:44.67,0:12:46.77,Default,,0000,0000,0000,,is to reduce the emotional memory,
Dialogue: 0,0:12:46.79,0:12:49.67,Default,,0000,0000,0000,,not get rid of the trauma\Nmemory altogether.
Dialogue: 0,0:12:50.44,0:12:53.56,Default,,0000,0000,0000,,This should make the responses\Nof those with PTSD
Dialogue: 0,0:12:53.59,0:12:55.91,Default,,0000,0000,0000,,more like those who have\Nbeen through trauma
Dialogue: 0,0:12:55.94,0:12:58.13,Default,,0000,0000,0000,,and not developed PTSD
Dialogue: 0,0:12:58.15,0:13:01.64,Default,,0000,0000,0000,,than people who have never\Nexperienced trauma in the first place.
Dialogue: 0,0:13:02.30,0:13:05.68,Default,,0000,0000,0000,,I think that most people would find that\Nmore ethically acceptable
Dialogue: 0,0:13:05.70,0:13:09.52,Default,,0000,0000,0000,,than a treatment that aimed\Nto create some sort of spotless mind.
Dialogue: 0,0:13:11.54,0:13:13.05,Default,,0000,0000,0000,,What about Propranolol?
Dialogue: 0,0:13:13.08,0:13:15.14,Default,,0000,0000,0000,,You can't give Propranolol to everyone,
Dialogue: 0,0:13:15.16,0:13:18.71,Default,,0000,0000,0000,,and not everyone wants to take drugs\Nto treat mental health conditions.
Dialogue: 0,0:13:19.24,0:13:21.92,Default,,0000,0000,0000,,Well, here Tetris could be useful.
Dialogue: 0,0:13:22.54,0:13:23.98,Default,,0000,0000,0000,,Yes, Tetris.
Dialogue: 0,0:13:25.43,0:13:27.20,Default,,0000,0000,0000,,Working with clinical collaborators,
Dialogue: 0,0:13:27.23,0:13:30.02,Default,,0000,0000,0000,,we've been looking at whether\Nbehavioral interventions
Dialogue: 0,0:13:30.05,0:13:33.62,Default,,0000,0000,0000,,can also interfere with\Nthe reconsolidation of memories.
Dialogue: 0,0:13:33.97,0:13:35.60,Default,,0000,0000,0000,,Now, how would that work?
Dialogue: 0,0:13:35.62,0:13:38.05,Default,,0000,0000,0000,,Well, we know that\Nit's basically impossible
Dialogue: 0,0:13:38.07,0:13:40.02,Default,,0000,0000,0000,,to do two tasks at the same time
Dialogue: 0,0:13:40.05,0:13:43.47,Default,,0000,0000,0000,,if they both depend on\Nthe same brain region for processing.
Dialogue: 0,0:13:43.83,0:13:46.16,Default,,0000,0000,0000,,Think trying to sing along to the radio
Dialogue: 0,0:13:46.18,0:13:48.26,Default,,0000,0000,0000,,while you're trying to compose an email.
Dialogue: 0,0:13:48.29,0:13:51.54,Default,,0000,0000,0000,,The processing for one\Ninterferes with the other.
Dialogue: 0,0:13:52.34,0:13:54.61,Default,,0000,0000,0000,,Well, it's the same when\Nyou retrieve a memory,
Dialogue: 0,0:13:54.64,0:13:55.90,Default,,0000,0000,0000,,especially in edit mode.
Dialogue: 0,0:13:55.92,0:13:59.92,Default,,0000,0000,0000,,If we take a highly visual symptom\Nlike flashbacks in PTSD
Dialogue: 0,0:13:59.94,0:14:02.99,Default,,0000,0000,0000,,and get people to recall\Nthe memory in edit mode
Dialogue: 0,0:14:03.01,0:14:06.27,Default,,0000,0000,0000,,and then get them to do\Na highly engaging visual task
Dialogue: 0,0:14:06.29,0:14:08.09,Default,,0000,0000,0000,,like playing Tetris,
Dialogue: 0,0:14:08.11,0:14:12.41,Default,,0000,0000,0000,,it should be possible to introduce\Nso much interfering information
Dialogue: 0,0:14:12.44,0:14:13.75,Default,,0000,0000,0000,,into that memory
Dialogue: 0,0:14:13.78,0:14:16.41,Default,,0000,0000,0000,,that it essentially becomes meaningless.
Dialogue: 0,0:14:17.64,0:14:18.83,Default,,0000,0000,0000,,That's the theory,
Dialogue: 0,0:14:18.85,0:14:22.32,Default,,0000,0000,0000,,and it's supported by data\Nfrom healthy human volunteers.
Dialogue: 0,0:14:22.82,0:14:26.75,Default,,0000,0000,0000,,Now, our volunteers watched\Nhighly unpleasant films --
Dialogue: 0,0:14:26.77,0:14:30.31,Default,,0000,0000,0000,,so, think eye surgery,\Nroad traffic safety adverts,
Dialogue: 0,0:14:30.33,0:14:32.08,Default,,0000,0000,0000,,Scorsese's "The Big Shave."
Dialogue: 0,0:14:32.100,0:14:36.93,Default,,0000,0000,0000,,These trauma films produce\Nsomething like flashbacks
Dialogue: 0,0:14:36.96,0:14:40.69,Default,,0000,0000,0000,,in healthy volunteers\Nfor about a week after viewing them.
Dialogue: 0,0:14:41.79,0:14:45.11,Default,,0000,0000,0000,,We found that getting people\Nto recall those memories,
Dialogue: 0,0:14:45.13,0:14:48.18,Default,,0000,0000,0000,,the worst moments\Nof those unpleasant films,
Dialogue: 0,0:14:48.20,0:14:50.75,Default,,0000,0000,0000,,and playing Tetris at the same time,
Dialogue: 0,0:14:50.78,0:14:54.36,Default,,0000,0000,0000,,massively reduced the frequency\Nof the flashbacks.
Dialogue: 0,0:14:54.39,0:14:58.56,Default,,0000,0000,0000,,And again: the memory had to be\Nin edit mode for that to work.
Dialogue: 0,0:15:00.06,0:15:03.77,Default,,0000,0000,0000,,Now, my collaborators have since\Ntaken this to clinical populations.
Dialogue: 0,0:15:03.79,0:15:06.81,Default,,0000,0000,0000,,They've tested this in survivors\Nof road traffic accidents
Dialogue: 0,0:15:06.84,0:15:10.08,Default,,0000,0000,0000,,and mothers who've had\Nemergency Caesarean sections,
Dialogue: 0,0:15:10.10,0:15:14.20,Default,,0000,0000,0000,,both types of trauma\Nthat frequently lead to PTSD,
Dialogue: 0,0:15:14.22,0:15:17.09,Default,,0000,0000,0000,,and they found really promising\Nreductions in symptoms
Dialogue: 0,0:15:17.11,0:15:19.49,Default,,0000,0000,0000,,in both of those clinical cases.
Dialogue: 0,0:15:21.43,0:15:25.68,Default,,0000,0000,0000,,So although there is still much to learn\Nand procedures to optimize,
Dialogue: 0,0:15:25.71,0:15:28.84,Default,,0000,0000,0000,,these memory-destroying treatments\Nhold great promise
Dialogue: 0,0:15:28.86,0:15:31.25,Default,,0000,0000,0000,,for the treatment\Nof mental health disorders
Dialogue: 0,0:15:31.28,0:15:33.04,Default,,0000,0000,0000,,like PTSD.
Dialogue: 0,0:15:33.06,0:15:38.41,Default,,0000,0000,0000,,Maybe trauma memories do not need\Nto be a hell from which we cannot escape.
Dialogue: 0,0:15:39.27,0:15:41.03,Default,,0000,0000,0000,,I believe that this approach
Dialogue: 0,0:15:41.06,0:15:42.98,Default,,0000,0000,0000,,should allow those who want to
Dialogue: 0,0:15:43.01,0:15:45.08,Default,,0000,0000,0000,,to turn the page\Non chapters of their lives
Dialogue: 0,0:15:45.10,0:15:47.76,Default,,0000,0000,0000,,that they would prefer\Nto never have experienced,
Dialogue: 0,0:15:47.78,0:15:50.48,Default,,0000,0000,0000,,and so improve our mental health.
Dialogue: 0,0:15:51.24,0:15:52.43,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:15:52.45,0:15:53.49,Default,,0000,0000,0000,,(Applause)