Sleep deprivation eliminates fear generalization

We know that emotion affects memory. We know that attention affects perception (see, e.g., Visual perception heightened by meditation training; How mindset can improve vision). Now a new study ties it all together. The study shows that emotionally arousing experiences affect how well we see them, and this in turn affects how vividly we later recall them.

A new study has found that, when delivered quickly, a modified form of prolonged exposure therapy reduces post-traumatic stress reactions and depression.

Following previous research suggesting that the volume of the hippocampus was reduced in some people with chronic PTSD, a twin study indicated that this may not be simply a sign that stress has shrunk the hippocampus, but that those with a smaller hippocampus are at greater risk of PTSD. Now a new study has found that Gulf War veterans who recovered from PTSD had, on average, larger hippocampi than veterans who still suffer from PTSD. Those who recovered had hippocampi of similar size to control subjects who had never had PTSD.

Following a study showing that playing Tetris after traumatic events could reduce memory flashbacks in healthy volunteers, two experiments have found playing Tetris after viewing traumatic images significantly reduced flashbacks while playing Pub Quiz Machine 2008 (a word-based quiz game) increased the frequency of flashbacks. In the experiments, volunteers were shown a film that included traumatic images of injury.

A mouse study has revealed the brain becomes overly stimulated after a traumatic event causes an ongoing, frenzied interaction between two brain proteins long after they should have disengaged. However, the injection of newly developed drugs into the hippocampus within a five hour window calmed this process, and prevented the development of a post-traumatic fear response.

A study involving over 180,000 older veterans (average age 68.8 at study start), of whom 29% had PTSD, has revealed that those with PTSD had a significantly greater risk of developing dementia. Over the seven years of the study, 10.6% of the veterans with PTSD developed dementia compared to 6.6% of those without PTSD. When age was used as the time scale, the risk for those with PTSD was more than double. Results were similar when those with a history of head injury, substance abuse, or clinical depression, were excluded.

A study in which nearly 50 participants consumed either alcohol (.4 or .8 g/kg, around 2 or 4 glasses of wine) or a placebo drink, performed a memory task, then were shown a video of serious road traffic accidents, has found that those given the smaller amount of alcohol experienced more flashbacks during the next week than those given the larger amount of alcohol, and those given no alcohol.

Can you help protect yourself from the memory of traumatic events? A new study suggests that, by concentrating on concrete details as you live through the event, you can reduce the number of intrusive memories later experienced.