Latest Research News

In the experiment, rats learned which lever to press to receive water, where the correct lever depended on which lever they had pressed previously (the levers were retractable; there was a variable delay between the first and second presentation of the levers). Microelectrodes in the rats’ brains provided data that enabled researchers to work out the firing patterns of neurons in CA1 that resulted from particular firing patterns in CA3 (previous research had established that long-term memory involves CA3 outputs being received in CA1).

Given all the research showing the importance of sleep for consolidating memories, it should come as no great surprise that the reverse is also true: depriving yourself of sleep could help you forget experiences you would prefer not to remember.

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.

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.

Recent rodent studies add to our understanding of how estrogen affects learning and memory. A study found that adult female rats took significantly longer to learn a new association when they were in periods of their estrus cycle with high levels of estrogen, compared to their ability to learn when their estrogen level was low. The effect was not found among pre-pubertal rats. The study follows on from an earlier study using rats with their ovaries removed, whose learning was similarly affected when given high levels of estradiol.

‘Face-blindness’ — prosopagnosia — is a condition I find fascinating, perhaps because I myself have a touch of it (it’s now recognized that this condition represents the end of a continuum rather than being an either/or proposition). The intriguing thing about this inability to recognize faces is that, in its extreme form, it can nevertheless exist side-by-side with quite normal recognition of other objects.

I’m not at all sure why the researcher says they were “stunned” by these findings, since it doesn’t surprise me in the least, but a series of experiments into the role of imagination in creating false memories has revealed that people who had watched a video of someone else doing a simple action often remembered doing the action themselves two weeks later.

Findings that children are less likely than adults to distort memories when negative emotions are evoked has significant implications for the criminal justice system. Experiments involving children aged seven and 11, and young adults (18-23) found that when they were shown lists of closely related emotional words (e.g. pain, cut, ouch, cry, injury), they would tend to mistakenly remember a related word (e.g. hurt) although it had not been present.

A study assessing the performance of 200 people on a simulated freeway driving task, with or without having a cell phone conversation that involved memorizing words and solving math problems, has found that, as expected, performance on both tasks was significantly impaired. However, for a very few, performance on these tasks was unaffected (indeed their performance on the memory task improved!). These few people — five of them (2.5%) — also performed substantially better on these tasks when performed alone.

As we all know, being interrupted during a task greatly increases the chance we’ll go off-kilter (I discuss the worst circumstances and how you can minimize the risk of mistakes in my book Planning to remember). Medication errors occur as often as once per patient per day in some settings, and around one-third of harmful medication errors are thought to occur during medication administration.

When we tell people about things that have happened to us, we shape the stories to our audience and our purpose. The amount of detail we give and the slant we give to it depends on our perceptions of our audience and what we think they want to hear. Does this change our memory for the event? Certainly we are all familiar with the confusion we get after we have been telling a particular story for years — we’re no longer sure what really happened and what we’ve added or subtracted to make a better story.

Tversky, Barbara & Marsh, Elizabeth J. 2000. Biased retellings of events yield biased memories. Cognitive Psychology, 40, 1-38.

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