{"id":526204,"date":"2010-04-13T08:00:36","date_gmt":"2010-04-13T12:00:36","guid":{"rendered":"http:\/\/blogs.discovermagazine.com\/notrocketscience\/?p=1355"},"modified":"2010-04-13T08:00:36","modified_gmt":"2010-04-13T12:00:36","slug":"amnesiacs-show-that-emotions-linger-long-after-memories-fade-not-exactly-rocket-science","status":"publish","type":"post","link":"https:\/\/mereja.media\/index\/526204","title":{"rendered":"Amnesiacs show that emotions linger long after memories fade | Not Exactly Rocket Science"},"content":{"rendered":"

\"Guy-Pearce_Memento\"I can still remember the details of my wedding day with the most crystalline vividness, from the flower arrangements to the design of the invitations to the contents of my speech. I can also easily recall the sense of elation, hope and fulfilment. These emotional memories are very much fused to my memories of the events themselves, but they aren\u2019t one and the same. A new study suggests that, like everyone else, I recorded these emotional memories independently of the factual aspects of the day.<\/p>\n

Typically, the happiness of a wedding day or the sadness of a death becomes inextricably linked to the details of those events, as we repeatedly replay and reflect on them in our heads. To see the true split between an emotional event and the emotions it triggers, you need some very special conditions. Justin Feinstein<\/a> from the University of Iowa College of Medicine found some \u2013 the brains of amnesiac patients.<\/p>\n

Feinstein worked with a group of five patients who had a rare condition called anterograde amnesia<\/a>, the same one that afflicted the protagonist of Memento<\/em>. All the patients had suffered severe brain damage to both halves of their hippocampus<\/a>, a part of the brain that\u2019s essential for long-term memory. As a result, they couldn\u2019t form any lasting memories after the point when they sustained their injuries. For the rest of their lives, new facts and experiences are like whispers on a breeze, lingering for moments before vanishing again.<\/p>\n

However, it seems that these patients can retain feelings of happiness or sadness long after they\u2019ve forgotten the events that triggered these emotions. Feinstein asked the quintet to watch film clips that either portrayed tragic scenes of loss or death, or comedic scenes of humour and laughter.<\/p>\n

<\/span>Around 5-10 minutes after the clip finished, each patient did a memory test about what they saw. Despite this short gap, the amnesiacs had little or no factual memory for the clips. Most could only remember a handful of details and some couldn\u2019t recall any. A group of five normal people with a working hippocampus had no such problems; they remember around 6 to 8 times as many details as the amnesiacs.<\/p>\n

They also answered a detailed questionnaire about their current feelings, before watching the clips, immediately after, just after the memory test, and a final time after half an hour or so. These results were very different. All five amnesiacs responded in the right way, frowning and crying at the sad clips while laughing and smiling at the happy ones. Even afterwards, when their memories of the films\u2019 content had faded, they still stayed emotional for at least half an hour. Even those with the most severe factual deficits managed to hold onto the film\u2019s emotional stings.<\/p>\n

\"Recall_sadness\"Of course, when you\u2019ve only got a sample size of five people (and patients with anterograde amnesia aren\u2019t exactly easy to come by), statistics aren\u2019t really working in your favour. Feinstein acknowledges this, but he notes that every one of the amnesiacs showed the persistent emotions. Consider just one of the patients, known as Am1. The sad clips really got to her and she cried for several minutes. Afterwards, she couldn\u2019t remember a single detail about them, but her sadness lingered for well over half an hour.<\/p>\n

This separation between emotional and factual memories seems incredibly counter-intuitive and Feinstein stresses that it would be difficult, if not impossible, to see it in patients without amnesia. For now, we don\u2019t know how long these emotional memories last for, but the important point is that they can be dissociated from factual recollections. Nor do we know how the amnesiacs keep their emotional memories; perhaps the state of their bodies gives them a clue.<\/p>\n

Nonetheless, these results support a fascinating<\/a> and widely misinterpreted<\/a> study that I wrote about last year, which showed that a drug called propanolol could erase the emotional sting<\/a> of scary memories. Merel Kindt trained volunteers to fear images of spiders by pairing them with electric shocks. If they were given propranolol, they still expected to receive a shock when they saw the spidery picture but they weren\u2019t afraid of the prospect. The drug hadn\u2019t so much erased their memories, as dulled their emotional sting.<\/p>\n

Kindt describes Feinstein’s research as “fascinating” and says that “the data are nicely in line with our own”. But the result that really grabbed her attention was that sad memories lingered to a greater <\/em>extent in amnesiacs than in normal volunteers. One of the patients, Am2, described her feelings in an interview after the experiment. She said, \u201cIt\u2019s not so much with the happy or the good feelings. You just kind of accept them. You don\u2019t worry about why. It\u2019s more for what I would call negative feelings… like when I\u2019m feeling really sad, then I have to find out why. \u201c She added, \u201cThey don\u2019t go away.\u201d<\/p>\n

Feinstein suggests that the emotions stick around precisely because the patients don\u2019t have a clear understanding of why they\u2019re feeling sad. Bereft of that knowledge, they can\u2019t deal with their feelings. Kindt says that this could easily have been tested by giving the volunteers an explicit reason for their lingering sadness, and she’s disappointed that this wasn’t done. “Nevertheless,” she says, “the data are strong.”<\/p>\n

That has big implications for the way people with memory disorders are cared for. It suggests that something could affect the mood of a person with, say, Alzheimer\u2019s disease, even if they\u2019ve forgotten about the event itself. They might quickly forget a visit from a family member or a funny joke but the good mood might last long after their company has gone and the punchline is forgotten.<\/p>\n

On the flipside, Feinstein writes, \u201cRoutine neglect from staff at nursing homes may leave the patient feeling sad, frustrated, and lonely (even though the patient can\u2019t remember why).\u201d He adds, \u201cWe provide clear evidence showing that the reasons for treating amnesic patients with respect and dignity go beyond simple human morals.\u201d<\/p>\n

Studies like these show that the fanciful world of Eternal Sunshine of a Spotless Mind <\/em>is very much a fictional one. Erasing a painful memory<\/a> may not erase the emotional stings that accompanied them. In fact, it might make things worse, which has ramifications for treatments<\/a> aimed at<\/a> selectively erasing fearful memories in, say, people with post-traumatic stress disorder.<\/p>\n

Remember that Feinstein\u2019s amnesiacs held onto their sad feelings longer than usual because they couldn\u2019t remember the source of their sadness. If this effect applies more generally, it might mean that \u201cerasing negative memories could have the paradoxical effect of actually prolonging (rather than alleviating) feelings of distress.<\/p>\n

Addendum: <\/strong>It is rare to read a scientific paper that is written so nicely that I end up liberally quoting large chunks of it, because my own take would be less eloquent. It\u2019s also relatively rare to see the ethical and social implications of the research considered in a meaty portion of the discussion, rather than in a throwaway concluding line. Hats off to Feinstein and his co-authors Melissa Duff<\/a> and Daniel Tranel<\/a> for their efforts.<\/p>\n

Reference: <\/strong>PNAS http:\/\/dx.doi.org\/10.1073\/pnas.0914054107<\/a><\/p>\n

More on memory: <\/strong><\/p>\n