In an earlier post, I summarized some Japanese research showing that working memory capacity can be increased in young children and that such increase even improves IQ. Accumulating evidence seems to indicate that working memory, with proper training, can be improved in anyone, even adults. Improved working memory results in improved attention (recall my other posts about how the main memory problem in aging is usually not memory per se but poor attentiveness), better reasoning ability, and better self control.
I recently found a paper in which lasting increases in brain function were produced in healthy adults by only 5 weeks of practice on three working-memory tasks that involved the location of objects in space. Subjects performed 90 trials per day on a training regimen (CogMed) and MRI scans showed increased activity in the cortical areas that were involved in processing the visual stimuli. Brain activity increases in these areas appeared within the first week and grew over time.
Similar results have been reported by other investigators. In a few cases, where different kinds of stimuli were used, memory training induced a decrease of brain activity in certain areas, which is interpreted to indicate that the trained brain did not have to work as hard.
While we clearly don’t understand things very well, it seems clear that working memory training not only improves memory capability but also causes lasting changes in the brain.
Reference:
Olesen, P. J., Westerberg, H., and Kingberg, T. 2004. Increased prefrontal and parietal activity after training of working memory. Nature Neuroscience. 7: 75-79.
Wednesday, October 3, 2007
Saturday, September 8, 2007
Losing Your Past
Do you remember the names of your elementary-school teachers? How about the name of the bully in middle school? Or names of your friends when you were a kid? These are all things you remembered well at one time and remembered for a long time. But you may well have forgotten by now.
Scientists like to talk about "long-term" memory, but even long-term memory has its limits. A recent study on rats suggests what it takes to sustain longer term memories. Rats in the study learned a "bait shyness" task. Rats were given a drink of saccharin-flavored water, and then shortly afterwards injected with lithium, which made them nauseated. This was a typical conditioned learning situation, as with Pavlov's dogs. In this case, rats typically remember to avoid such water for many weeks. This is the basis for "bait shyness." If rats survive a rat poisoning episode, they will avoid that bait in the future. However, in this experiment,one group of rats received an injection directly into the part of the brain that holds taste memories.This injection contained a drug that blocks a certain enzyme, a protein kinase. These rats lost their learned taste aversion. The bad memory was lost irrespective of when the injection was made during the 25 days after learning occurred.Giving the enzyme blocker before learning had no effect on the ability to learn to avoid the flavored water.The protein kinase thus seems to be necessary for sustaining a long-term memory. It is possible that other long-term memories the rats may have had were also wiped out by the enzyme-blocking drug, but this was not tested.
So what is the practical importance of these findings? I suggest that even "long-term" memories have to get rehearsed once and a while or they may eventually fail to remember (see my earlier post on "reconsolidation" of memories. Or if you do remember, there is a good chance that the memory is corrupted, that is, not totally correct. The consequence is that things that happened long ago may be either forgotten, misremembered, or so buried in memory that it takes a great deal of cuing to retrieve the memory. I have a whole chapter in my book, Thank You Brain for All You Remember on the subject of false memory.
The study showed that a certain enzyme has to be present to preserve a memory. Without the enzyme, the memory disappears. What sustains the enzyme? I suspect it is rehearsal and periodic reactivation of the memory, although this possibility has not been tested yet. Some scientists are excited about the possibility of developing a drug that would eliminate the enzyme or insure its presence. The problem with that, however, is that the drug could abolish old memories that you might not want to forget (like your name) or may cause you to remember too much that is now irrelevant.
Source:
Shema, R., Sacktor, T. C., and Dudai, Y. 2007. Rapid erasure of long-term memory associations in the cortex by an inhibitor of PKM. Science. 317:951-953.
For more summaries of recent research with practical application, click here.
Scientists like to talk about "long-term" memory, but even long-term memory has its limits. A recent study on rats suggests what it takes to sustain longer term memories. Rats in the study learned a "bait shyness" task. Rats were given a drink of saccharin-flavored water, and then shortly afterwards injected with lithium, which made them nauseated. This was a typical conditioned learning situation, as with Pavlov's dogs. In this case, rats typically remember to avoid such water for many weeks. This is the basis for "bait shyness." If rats survive a rat poisoning episode, they will avoid that bait in the future. However, in this experiment,one group of rats received an injection directly into the part of the brain that holds taste memories.This injection contained a drug that blocks a certain enzyme, a protein kinase. These rats lost their learned taste aversion. The bad memory was lost irrespective of when the injection was made during the 25 days after learning occurred.Giving the enzyme blocker before learning had no effect on the ability to learn to avoid the flavored water.The protein kinase thus seems to be necessary for sustaining a long-term memory. It is possible that other long-term memories the rats may have had were also wiped out by the enzyme-blocking drug, but this was not tested.
So what is the practical importance of these findings? I suggest that even "long-term" memories have to get rehearsed once and a while or they may eventually fail to remember (see my earlier post on "reconsolidation" of memories. Or if you do remember, there is a good chance that the memory is corrupted, that is, not totally correct. The consequence is that things that happened long ago may be either forgotten, misremembered, or so buried in memory that it takes a great deal of cuing to retrieve the memory. I have a whole chapter in my book, Thank You Brain for All You Remember on the subject of false memory.
The study showed that a certain enzyme has to be present to preserve a memory. Without the enzyme, the memory disappears. What sustains the enzyme? I suspect it is rehearsal and periodic reactivation of the memory, although this possibility has not been tested yet. Some scientists are excited about the possibility of developing a drug that would eliminate the enzyme or insure its presence. The problem with that, however, is that the drug could abolish old memories that you might not want to forget (like your name) or may cause you to remember too much that is now irrelevant.
Source:
Shema, R., Sacktor, T. C., and Dudai, Y. 2007. Rapid erasure of long-term memory associations in the cortex by an inhibitor of PKM. Science. 317:951-953.
For more summaries of recent research with practical application, click here.
Saturday, August 11, 2007
Students Who E-communicate Have Lower Grades
A new study of 517 California high-school students found that grades were lower in those who socially interacted over the Internet using MySpace, instant messaging (IM) accounts, or who used cell phones. In the study, students answered a questionnaire on what social networking devices they used and when they used them. The answers were paired with the grades (from the previous year and the most recent report card).
In this study, 72% of the students had a My Space account, 76% had a cell phone, and 68% had an IM address. Those who had a MySpace account had significantly lower grades than those without an account. The same was true for those that used IM, compared with those who did not. Cell phone use was also associated with lower grades and the effect was magnified if text messaging was used on cell phones. Not surprisingly, if these devices were used during homework, the grades were even lower than for students who used these technologies outside of homework. Almost half reported text messaging during class time, and their grades were lower than the students who only used IM outside of class.
These are correlational data and do not prove that using these devices causes lower grades. But it is a good bet. Multi-tasking, as when using the communication devices while trying to do homework or learn in class, is well-known to interfere with memory . Poor memory yields lower grades. See my other posts on multi-tasking.
Source:
Pierce, Tamyra, and Vaca, Roberto. 2007. Distracted: academic performance differences between teen users of MySpace and other communication technologies. Proceedings EISTA. Orlando, FL. July. http://www.cyber-inf.org/imsci2007/Program/html/program-5.htm
For more summaries of recent research with practical application, click here.
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