Thursday, 23 March 2017
When You Come Into a Room and Forget What You Were Going To Do There
Of all the psychological effects that have been given specific names (the placebo effect, the McGurk effect, the Coolidge effect, etc.), the “doorway effect” is one of the most familiar and yet also one of the most surprising. We have all experienced it: you’re at home, you go from one room into another, and then you forget what you were planning to do there!
As the first article linked to below notes, the French poet Paul Valéry once said that the purpose of psychology is to give us a completely different idea of the things we know best. In this sense, the doorway effect might be considered a perfect example of the kinds of phenomena that psychologists study. And in fact, both this article and the second (from a site that specializes in explaining the psychological mechanisms behind our most familiar behaviours) show how empirical and theoretical data from contemporary psychology shed a different light on this apparent memory failure and instead depict it as a strategy that the human brain uses to adapt to the limited storage capacity of its working memory.
Scientists have known for some time that the memory systems of the human brain are contextual. Thus, it stands to reason that if you decide to perform a task in which you must maintain your intention for a little while, your brain will be subject to the effects of context during that interval. But as Gabriel A. Radvansky and his colleagues showed in their 2011 study, the doorway effect is more than just that. In this study, the subjects played an ingenious video game in which they picked an object up off a table, put the object it in a “virtual backpack” in which they could not see it, then carried it to another table, put the object down, and picked up a different one. In some cases, the subject simply moved from one table to another in the same room, in other cases from a table in one room to a table in another room, and in still others, from a table in one room to a table in another and then back again. In both of the last two cases, the subjects’ answers were slower and less specific when they had gone into another room, even if they had then returned to the original one. These results demonstrated that it was essentially their having gone into the other room (and not whether or not they had returned to the first one) that erased or destabilized their memory.
We can see the potential adaptive value of this phenomenon when we consider the limited capacity of human working memory. When we are taken out of one particular context and immersed in another, we are faced with new challenges and must adapt to them, and one way to do so is to “empty” our working memory so that we can store something new in it. It is of course possible, as well as adaptive, for us to keep our attention on a specific objective despite the change in context, but it demands more “top-down” concentration to offset the “bottom-up” imperatives of the new environment.
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Because my memory, like anyone else’s, is highly associative, writing this post has made me remember an image that I saw recently that illustrated the doorway effect quite specifically. It was one of some 300 images in Here, a sort of graphic novel by Richard McGuire that completely blew me away as soon as I understood what he was doing in it. In Here, everything is viewed from the same point in space (in the present time, a particular corner of the living room of the house in New Jersey where the author grew up in the mid-20th century). But the surprise comes as the ensuing images shift time frames, showing the view from that same point in space at different points in time across many years.
At the start of the book, you understand that you’re in the author’s childhood living room. In some cases, two or three images depict consecutive moments in time. But then the images suddenly leap from the 1950s to the 1980s, then back to the 1960s, then forward to 2005. And then you’re looking at a swamp! Yes, you’re still in the same place, but now, instead of exploring the author’s memories, you’re in the early Neolithic Age (about 10,000 B.C.E.), exploring the memory of our species! Farther along in the book, you go back 50,000 years into the past, and still farther, you are projected into the future: the year 2052. For me, the most striking image for me was the one composed of nothing but greenish clouds, suggesting that I was looking back over 3 billion years, to the origins of life on Earth, but still from the place where the house in which McGuire grew up would be built in 1907.
To get an idea of the variety of the scenes illustrated in this book, enter the string “Here+McGuire” in Google Images or another image search engine. They range from native Americans in a forest glade in the early 1600s to the author’s living room being repainted in the 1990s to the image at the start of this post, where a woman has walked into the living room and is saying to herself, “Hum… Now why did I come in here again?” Many people regard Here as a kind of UFO in the world of graphic novels. I don’t know whether McGuire was familiar with the expression “doorway effect” when he designed it. But if he decided to depict this particular situation, it was because it represents such a common, emblematic phenomenon in human psychology.
Wednesday, 22 February 2017
To Retain Information Better, Wait a Few Hours, Then Go for a Run!
The study that I want to tell you about today was done by Eelco V. van Dongen and his colleagues and is entitled “Physical Exercise Performed Four Hours after Learning Improves Memory Retention and Increases Hippocampal Pattern Similarity during Retrieval.”
This study’s findings can be summed up as follows: if you have just made a new mental association and want to remember it better, wait a couple of hours, and then go do some exercise! In van Dongen’s study, three groups of subjects performed a memory-encoding task. One group performed exercise immediately after, one did so four hours after, and the third did not perform any exercise at all. When the three groups were tested for their retention of the encoded memory two days afterward, the group that had exercised four hours after the task showed the best retention among the three groups. (more…)
Friday, 10 February 2017
You Don’t Catch a Ball by Calculating Its Trajectory, You Catch It by Moving
Today I’d like to talk about a problem that is a classic both for baseball players and for cognitive scientists. And the way that baseball players solve it has helped cognitive scientists to better understand the important role that the body plays in cognition.
The problem is as follows: how does a baseball player go about catching a baseball that has been hit high into the air, especially when the player is in centre field and the ball is following a long, parabolic trajectory that would otherwise cause it to land several metres from where the player is standing? How does the player go about calculating this trajectory and moving, in just a few seconds, to the right place to catch the ball? This is what has long been known in English as “the outfielder problem.” (If you’re more of a soccer fan, imagine a backfielder successfully heading a long throw-in by the goalkeeper.) (more…)
Monday, 9 January 2017
A First Brain-Imaging Study on the Effects of LSD
“This is to neuroscience what the Higgs boson was to particle physics.”
This eye-catching remark comes from neuropsychopharmacologist David Nutt, and he is talking about a study on which he was the senior researcher: “Neural correlates of the LSD experience revealed by multimodal neuroimaging”, published in the journal Proceedings of the National Academy of Sciences in April 2016. And like the results of the research on the Higgs boson, the results of Nutt’s study confirmed the theory—in this case, that the observed changes in brain activity would provide a very good picture of the mental state produced by an “acid trip”. (more…)
Monday, 12 December 2016
Some Amazing Predictions Based on Brain Connectivity
This week, I’d like to tell you about two very interesting articles. The first, by Emily S. Finn and her colleagues, was published in the journal Nature Neuroscience in October 2015 and is entitled “Functional connectome fingerprinting: identifying individuals using patterns of brain connectivity.” As its title suggests, Finn’s research team successfully identified individuals from patterns not on their fingertips, but rather in their brains! (more…)