The brain’s ability to learn and form memories of day-to-day facts and events depends on the hippocampus, a structure deep within the brain. But is the hippocampus still maintaining the memory of, say, the commencement address at your college graduation 20 years ago? The latest evidence suggests that as memories age, the hippocampus’s participation wanes.

In a 2006 study, neuroscientist Larry R. Squire of the University of California, San Diego, and the Veterans Affairs San Diego Healthcare System studied patients who had hippocampal damage. These indi­viduals did not remember details of newsworthy events that occurred in the five to 10 years prior to their injuries, but they did recall older events.

Building on those results, Squire turned to healthy brains. His team questioned 15 people in their 50s and 60s about events in the news over the past 30 years while scanning the participants’ brains with functional MRI. To single out brain activity related to the date of the event, the researchers separately evaluated activity tied to learning and remem­bering the test questions. They also accounted for the richness of participants’ recollections of events, to make sure the degree to which someone was able to recall an event did not influence the data.

Squire’s team reported in January that activity in the hippocampus steadily declined as subjects remembered events that were up to 12 years old. With more remote memories, the structure’s activity leveled off. In contrast, areas in the frontal, temporal and parietal lobes displayed increasing activity for recalled events from those dozen years, then reached a plateau during older remembrances.

The biology behind how the brain makes and keeps memories is not fully understood, Squire notes, but it appears that, initially, a memory resides in the hippocampus and in areas the structure connects to in the neocortex, the outer part of the cerebral cortex. “A time comes when the cortical regions important to a memory are connected [to one another] heavily enough to form a stable representation,” Squire says. “Then the hippocampus isn’t needed to hold the whole thing together.”

Original article here

Myfitbrain brain games

Researchers at MIT’s Picower Institute for Learning and Memory conducted learning and memory tasks using transgenic mice that were induced to lose a significant number of brain cells. Following Alzheimer’s-like brain atrophy, the mice acted as though they did not remember tasks they had previously learned.  But after taking HDAC inhibitors, the mice regained their long-term memories and ability to learn new tasks. In addition, mice genetically engineered to produce no HDAC2 at all exhibited enhanced memory formation.

The fact that long-term memories can be recovered by elevated histone acetylation supports the idea that apparent memory “loss” is really a reflection of inaccessible memories, Tsai said. “These findings are in line with a phenomenon known as ‘fluctuating memories,’ in which demented patients experience temporary periods of apparent clarity,” she said.

A team led by researchers at MIT’s Picower Institute for Learning and Memory has now pinpointed the exact gene responsible for a 2007 breakthrough in which mice with symptoms of Alzheimer’s disease regained long-term memories and the ability to learn. In the latest development, reported in the May 7 issue of Nature, Li-Huei Tsai, Picower Professor of Neuroscience, and colleagues found that drugs that work on the gene HDAC2 reverse the effects of Alzheimer’s and boost cognitive function in mice.

Original article here

Why is it that once you learn something incorrectly (say, 7 X 9 = 65), it seems you never can correct your recall?
—J. Kruger, Cherry Hill, N.J.

Cognitive psychologist Gordon H. Bower of Stanford University answers:

Identifying, correcting and averting our memory errors are part of a cognitive process called memory monitoring. Incorrect associations can be tough to change, but we can use techniques to retrain our brain.

When strong habits impede our ability to acquire a desired new habit or association, we experience a common phenomenon known as proactive interference. Wrong associations appear in common spelling errors such as “wierd” for “weird” and “neice” for “niece.” Persistent mistaken connections also can cause embarrassing errors, such as calling a man’s second wife by the name of his first. Interference is stronger the more previous wives you’ve had to deal with, and it is more difficult to overcome the stronger the habits are.

Accurate memory monitoring requires a well-functioning prefrontal cortex (PFC). Young children, who have an immature PFC, and stroke patients with extensive PFC damage make more errors as a result of memory-monitoring failures. They are more likely to confuse the source of information they recall, and they are more susceptible to accepting as true an event they only imagined.

You can overcome proactive interference by consistent (even silent) correction, especially when you space rehearsals over time. But it takes some conscious practice. We have to identify (or be told) when we have just made an error so that we can correct it immediately. Our inability to do so is typically the cause of the error’s persistence.

Building on the correct information can help you learn new associations to it: add something to change how you retrieve the item from your memory. You might replace your question “Name of John’s wife?” with “Name of John’s second wife?”; or use an elaboration that contains the accurate information, such as “We are weird” or “My niece is nice”; or convert 7 X 9 into 7 X (10 – 1) = 70 – 7 = 63. As you practice the elaborated association, the simpler direct association (7 X 9 = 63) eventually replaces the earlier one, which weakens without rehearsals. Labeling and rehearsing the wrong association (for example, saying to yourself, “7 X 9 is not 63”), however, are distinctly counterproductive.

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Throughout the day you collect lots of miscellaneous facts. Almost none of this gets put into long term memory until you sleep. If your sleep too short, some of it gets left out of long term memory never to be heard from again.

Think of it like this: you have just thrown everything in your apartment on the floor, thus nothing is organized. Eventually it would be hard to find things. In trying to find specific items, you break your belongings, unless of course, you are extremely careful. So, you call a maid in to clean up while you step out.  The maid is smart and knows exactly where to put everything so you can find it later.

When you sleep, it is like that smart maid comes into your brain.  Your brain goes into hyper drive to clean up all the facts from the day and put them away for long term retrieval.  Some facts that were not very important and you thought about only once get discarded so as not to clutter up your long term memory.

If you only sleep a short time, it is like interrupting the maid.  Not everything is cleaned up and put away.  Some people have more efficient maids and only need 6 hours of sleep, but most people need more to get all the information from the day cleaned up and organized.

People who go days without sleep really begin to see drastic effects.  If they go long enough without sleep they can even begin to hallucinate.  The human brain has evolved to only hold so much information before it needs to get organized.  Its like reaching a point when you your is so full of stuff you can longer walk around in it, much less find anything.

If you fall asleep with a problem on your mind, your brain will even work on that while you sleep.  Sleep is an especially good time for the brain to work on problems that you are stuck on trying to figure out.  Your brain can be very creative during this time and often you can awake with a brand new solution to try.  So, do not stay awake trying to figure it out, but sleep on it.

So for your brains sake, get a full nights sleep so that all the prior days information is properly put away and you can begin a new day with lots of room for new information.

While a person sleeps, their brain is actually working very hard to consolidate everything they have learned that day so they can recall things from long term memory.  If a person’s sleep is interrupted, their ability to remember what they learned that day is seriously degraded.  So, pulling those all-nighters in college may have helped get through the exam for that day.  But it probably severely  hurt the chances of remembering that information for the long term.

If you fail to get enough sleep, your ability to remember what you learned has been shown to suffer dramatically.  People who got less sleep than their body demanded were 80% less effective than people who got the sleep their body required.   People who stay awake for many days, have been shown to display severe psychological problems such as hallucinations.

Naps are good for you. As soon as you wake up, your body begins to tell you to go to sleep.  Around 3 PM, your body’s natural sleep rhythm wants a 25 minute nap.  People who nap actually perform better the rest of the day than people who stay awake all day.  Your brain revitalizes itself and is better able to focus for the second half of your day.

Sleep deprived people have issues being creative.  Tests have shown that the brain of people who have not gotten the proper amount of sleep actually act differently.  The frontal lobe is associated with a person’s speech as well as novel and creative thinking.  In sleep deprived people, there is a significant decrease in activity in this area of the brain.  While activity is seen within the parietal lobes of rested people as they think through math problems no corresponding activity is visible within the brains of sleep-deprived subjects.

It is important to have a consistent sleep schedule.  Our bodies and the chemicals it produces work best when it can depend on a schedule.  One study showed that by merely anticipating a wake-up time, our bodies will spike ACTH and cortisol higher than normal.  By anticipating our wake-up time we can give ourselves that hormonal jolt of energy to hop out of bed with ease.  Depressed people do not have that anticipation and never get that hormonal boost.

Our brain needs sleep to form long term memories and repair itself.  Depriving our brains of the sleep it requires (the amount which is different for each person) and you can ensure that your brain will NOT operate at it peak efficiency no matter how many Myfitbrain games you play.