Posts Tagged‘fmri’

Slow Learner? You Might Be Thinking Too Hard.

Back in my school days I thought that skill was an innate thing, a quality that you were born with that was basically immutable. Thus things like study and practice always confused me as I felt that I’d either get something or I wouldn’t which is probably why my academic performance back then was so varied. Today however I don’t believe anyone is below mastering a skill, all that is required is that you put the required amount of time and (properly focused) practice in and you’ll eventually make your way there. Innate ability still counts for something though as there are things you’re likely to find much easier than others and some people are even just better in general at learning new skills. Funnily enough that latter group of people likely has an attribute that you wouldn’t first associate with that skill: lower overall brain activity.

Learning Stuff

Research out of the University of California – Santa Barbara has shown that people who are most adept at learning new tasks actually show a lower overall brain activity level than their slow learning counterparts. The study used a fMRI machine to study the subject’s brains whilst they were learning a new task over the course of several weeks and instead of looking at a specific region of the brain the researchers focused on “community structures”. These are essentially groups of nodes within the brain that are densely interconnected with each other and are likely in heavy communication. Over the course of the study the researchers could identify which of these community structures remained in communication and those that didn’t whilst measuring the subject’s mastery of the new skill they were learning.

What the researchers found is that people who were more adept at mastering the skill showed a rapid decrease in the overall brain activity used whilst completing the task. For the slower learners many of the regions, namely things like the visual and motor cortexs, remained far more active for a longer period, showing that they were more actively engaged in the learning process. As we learn skills much of the process of actually doing that skill gets offloaded, becoming an automatic part of what we do rather than being a conscious effort. So for the slow learners these parts of the brain remained active for far longer which could, in theory, mean that they were getting in the way of making the process automatic.

For me personally I can definitely attest to this being the case, especially with something like learning a second language. Anyone who’s learnt a different language will tell you that you go through a stage of translating things into your native language in your head first before re-translating them back into the target language, something that you simply can’t do if you want to be fluent. Eventually you end up developing your “brain” in that language which doesn’t require you to do that interim translation and everything becomes far more automatic. How long it takes you to get to that stage though varies wildly, although the distance from your native language (in terms of grammatical structure, syntax and script) is usually the primary factor.

It will be interesting to see if this research leads to some developmental techniques that allow us to essentially quieten down parts of our brain in order to aid the learning process. Right now all we know is that some people’s brains begin the switch off period quicker than others and whatever is causing that is the key to accelerating learning. Whether or not that can be triggered by mental exercises or drugs is something we probably won’t know for a while but it’s definitely an area of exciting research possibilities.

Forgetting Might be an Adaptive Advantage.

Nearly all of us are born with what we’d consider less than ideal memories. We’ll struggle to remember where our keys our, draw a blank on that new coworker’s name and sometimes pause much longer than we’d like to remember a detail that should be front of mind. The idealised pinnacle, the photographic (or more accurately the eidetic) memory, always seems like an elusive goal, something you have to be born with rather than achieve. However it seems that our ability to forget might actually come from an evolutionary adaptation, enabling us to remember the pertinent details that helped us survive whilst suppressing those that might otherwise hinder us.

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The idea isn’t a new one, having existed in some form since at least 1997, but it’s only recently that researchers have had the tools to study the mechanism in action. You see it’s rather difficult to figure out which memories are being forgotten for adaptive reasons, I.E. to improve the survival of the organism, and which ones are simply forgotten due to other factors. The advent of functional Magnetic Resonance Imaging (fMRI) has allowed researchers to get a better idea of what the brain is doing at any one point, allowing them to set up situations to see what the brain is doing when it’s forgetting something. The results are quite intriguing, demonstrating that at some level forgetting might be an adaptive mechanism.

Back in 2007 researchers at Stanford University investigated the prospect that adaptive forgetting was potentially a mechanism for reducing the amount of brain power required to select the right memories for a particular situation. The hypothesis goes that remembering is an act of selecting a specific memory for a goal related activity. Forgetting then functions as an optimization mechanism, allowing the brain to more easily select the right memories by suppressing competing memories that might not be optimal. The research supported this notion, showing decreased activity in anterior cingulated cortex which is activated when people are weighing choices (like figuring out which memory is relevant).

More recent research into this phenomena, conducted by researchers at various institutes at the University of Birmingham and various institutes in Cambridge, focused on finding out if the active recollection of a specific memory hindered the remembering of others. Essentially this means that the act of remembering a specific memory would come at the cost of other, competing memories which in turn would lead to them being forgotten. They did this by getting subjects to view 144 picture and word associations and were then trained to remember 72 of them (whilst they were inside a fMRI machine). They were then given another set of associations for each word which would serve as the “competitive” memory for the first.

The results showed some interesting findings, some which may sound obvious on first glance. Attempting to recall the second word association led to a detriment in the subject’s ability to recall the first. That might not sound groundbreaking to start off with but subsequent testing showed a progressive detriment to the recollection of competing memories, demonstrating they were being actively repressed. Further to this the researchers found that their subject’s brain activity was lower for trained images than ones that weren’t part of the initial training set, an indication that these memories were being actively suppressed. There was also evidence to suggest that the trained memories showed the most average forgetting as well as increased activity in a region of the brain known to be associated with adaptive forgetting.

Whilst this research might not give you any insight into how to improve your memory it does give us a rare look into how our brain functions and why certain it behaves in ways we believe to be sub-optimal. Potentially in the future there could be treatments available to suppress that mechanism however what ramifications that might have on actual cognition is anyone’s guess. Needless to say though it’s incredibly interesting to find out why our brains do the things we do, even if we wished they did the exact opposite most of the time.