Trevor Ponder Human Memory

After undergoing surgery, chemotherapy, and radiation therapy for stage II breast cancer, Lori (who asked to be identified only by her first name) was looking forward to getting back to her normal, busy life as a working mother of two.

This image of the human brain uses colors and shapes to show neurological differences between two people. The blurred front portion of the brain is associated with complex thought. (Image courtesy of Arthur Toga, University of California, Los Angeles)

But within weeks of returning full-time to her job as a city planner, she knew something was wrong. “I couldn’t work, I couldn’t think,” she said. Before, multitasking had been second nature, but now it exhausted her. At home, she found that trying to do things like plan dinner for her family was more than she could cope with.

“My brain feels so heavy and tired…I can feel everything slowing down, getting cloudy,” she said.

Lori has the classic symptoms of chemobrain: cognitive changes associated with cancer or cancer treatment, most often experienced as difficulties with concentration, memory, multi-tasking, and planning ability. These changes usually first become apparent during chemotherapy (hence the name) and, in around 20 percent of survivors, persist well after treatment has ended.

A More Complicated Explanation

Although chemobrain was first identified and named by breast cancer survivors, research now suggests that the same constellation of symptoms also affects survivors of other cancers. Early studies of patients’ cognitive functioning after chemotherapy estimated that the number of survivors with chemotherapy-associated cognitive changes ranged from 17 percent to 75 percent.

When researchers began to measure cancer patients’ cognitive functioning both before and after chemotherapy, however, they were surprised to find that before undergoing chemotherapy, 20 to 30 percent of patients had lower cognitive performance than would be expected based on their age and education. Subsequent studies have consistently shown similar findings.

“This suggests that aspects of cancer biology may influence cognitive functioning, or that there are as-yet-unidentified shared risk factors for mild cognitive changes and the development of cancer,” said Dr. Tim Ahles, who studies chemobrain at Memorial Sloan-Kettering Cancer Center.

“It’s more complicated than chemotherapy,” added Dr. Ahles. “Almost no one who is treated for cancer receives only chemotherapy. Other aspects of treatment may be equally important to understanding changes in cognitive functioning.”

Increased Vulnerability

Evidence from animal and imaging studies suggests, for example, that the drug tamoxifen, widely used to treat hormone-receptor-positive breast cancer, may disrupt cognitive and other brain functions. In addition, some studies have found that hormonal agents such as goserelin and leuprolide may cause adverse cognitive effects in men who have prostate cancer.

Studies using functional magnetic resonance imaging have identified structural brain abnormalities in patients treated with chemotherapy. In a study using positron emission tomography imaging, breast cancer survivors who had received chemotherapy in the previous 5 to 10 years used more of their brains to perform a short-term memory task than control subjects who had never received chemotherapy, a sign that their brains are having to work harder to complete the task.

Findings from a preliminary study by Dr. Ahles and his colleagues at Dartmouth Medical School suggest that a form, or allele, of the APOE gene called ε4, which is associated with increased risk for Alzheimer’s disease, may be a genetic marker for increased vulnerability to chemobrain. In this study of 80 long-term survivors of breast cancer and lymphoma, participants with at least one ε4 allele had significantly lower scores on standard tests of visual memory and spatial ability and a tendency toward lower scores on psychomotor functioning than subjects who did not carry this allele.

Dr. Ahles and his team are currently analyzing the data from a larger study, looking at the role of genetic polymorphisms in the development of cancer-related cognitive changes. They are also investigating the hypothesis that patients whose cells have a reduced ability to repair the DNA damage caused by chemotherapy are at higher risk for chemobrain.

Dr. Patricia Ganz and her colleagues at UCLA’s Jonsson Comprehensive Cancer Center suspect that uncontrolled inflammation may be a cause of chemobrain. “Many of the patients in our breast cancer survivorship program who have cognitive complaints also have fatigue, sleep disturbance, or depression,” she said. “Our hypothesis is that polymorphisms in genes that regulate the immune system render some patients more vulnerable to this constellation of symptoms.”

Many cancer treatments, including surgery, radiation, chemotherapy, and immunotherapy, can increase inflammation, Dr. Ganz added, which may not resolve after treatment ends. “We have found that post-treatment fatigue is associated with specific single nucleotide polymorphisms in genes that code for interleukin-1 and interleukin-6, two cell-signaling molecules associated with both inflammation and cancer-related fatigue,” she explained. “Our research is examining whether disruption in immune regulation is also involved in the development of cognitive complaints.”

Treatment Studies

Research on treatments for chemobrain is still in its very early stages. Dr. Ganz is beginning a pilot study of rehabilitation strategies for affected breast cancer survivors. Some evidence suggests that medications that stimulate the central nervous system may moderate adverse cognitive effects.

Lori has obtained some improvement by taking the stimulant Adderall (dextroamphetamine and amphetamine). She also finds that exercise and getting a good night’s sleep help her feel more clear headed.

The most challenging aspect of chemobrain, she said, is its invisibility. “I look fine, so people think I’m well. But my brain still isn’t well.”

Dr. Julia Rowland, who directs NCI’s Office of Cancer Survivorship, is encouraged that this new body of research is bringing needed attention to and better scientific understanding of the cognitive problems that affect many survivors during and after treatment. “The very real challenges caused by cancer-related difficulties with memory and thinking have been poorly understood and are often dismissed when reported by survivors,” said Dr. Rowland. “Findings from these studies should empower survivors to ask their medical providers what can be done to help them improve their cognitive health, especially after treatment ends.”

Human Brain Memory chemobrain

Can human beings rev up their intelligence quotients, or are they stuck with IQs set by their genes at birth? Until recently, nature seemed to be the clear winner over nurture.

But new research, led by Swiss postdoctoral fellows Susanne M. Jaeggi and Martin Buschkuehl, working at the University of Michigan in Ann Arbor, suggests that at least one aspect of a person’s IQ can be improved by training a certain type of memory.

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See for yourself by trying Trevor Ponder’s training programs:
http://www.memoryonfire.com – audio book
http://www.elementsofmemory.com – PDF book
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Most IQ tests attempt to measure two types of
intelligence–crystallized and fluid intelligence. Crystallized
intelligence draws on existing skills, knowledge and experiences to
solve problems by accessing information from long-term memory.

Fluid intelligence, on the other hand, draws on the ability to
understand relationships between various concepts, independent of
any previous knowledge or skills, to solve new problems. The
research shows that this part of intelligence can be improved
through memory training.

“When it comes to improving intelligence, many researchers have
thought it was not possible,” says Jaeggi. “Our findings clearly
show this is not the case. Our brain is more plastic than we might
think.”

Jaeggi, Buschkuehl and Walter Perrig from Bern University,
Switzerland, along with Jon Jonides, their National Science
Foundation-supported colleague from the University of Michigan,
reasoned that just as crystallized intelligence relies on long-term
memory, fluid intelligence relies on short-term memory, or “working
memory,” as it is more accurately called. This is the same type of
memory people use to remember a phone number or an e-mail address
for a short time, but beyond that, working memory refers to the
ability to both manipulate and use information briefly stored in
the mind in the face of distraction.

Researchers gathered four groups of volunteers and trained their
working memories using a complex training task called “dual n-back
training,” which presented both auditory and visual cues that
participants had to temporarily store and recall.

Participants received the training during a half hour session held
once a day for either eight, 12, 17 or 19 days.  For each of these
training periods, researchers tested participants’ gains in fluid
intelligence. They compared the results against those of control
groups to be sure the volunteers actually improved their fluid
intelligence, not merely their test-taking skills.
The results were surprising. While the control groups made gains,
presumably because they had practice with the fluid intelligence
tests, the trained groups improved considerably more than the
control groups. Further, the longer the participants trained, the
larger were their intelligence gains.

“Our findings clearly show that training on certain memory tasks
transfer to fluid intelligence,” says Jaeggi. “We also find that
individuals with lower fluid intelligence scores at pre-test could
profit from the training.”

The results are significant because improved fluid intelligence
scores could translate into improved general intelligence as
measured by IQ tests. General intelligence is a key to determining
life outcomes such as academic success, job performance and
occupational advancement.

Researchers also surmise that this same type of memory training may
help children with developmental problems and older adults who face
memory decline. But, that remains to be seen, because the test
results are based on assessments of young, healthy adult
participants.

“Even though it currently appears very hard to improve these
conditions, there might be some memory training related to
intelligence that actually helps,” says Jaeggi. “The saying ‘use it
or lose it’ is probably appropriate here.”
via the NSF

Human Brain Memory improve memory, memory training, NSF

I just read a fascinating interview with Matthew Schulkind, a cognitive scientist at Amherst College.  He’s been studying older adults to figure out why popular songs stick in our heads so persistently.  (His ultimate aim is to see if music can help his patients with dementia regain lost memories.)

He believes musical memory is memory that doesn’t take conscious thought – like throwing a ball, or walking.  [This is often called “procedural memory”, compared to “declarative” memory which is for facts, like remembering a recipe for oatmeal cookies.)

Surprisingly, Older People Do NOT Have “Magical Memory” For Songs From Their Youth

He was surprised by this, but older people don’t have some savant-like ability to recall songs from their childhood.  Even when prompted by the first few bars of the song.  However, if they had an emotional connection to a song (meaning, the song from long ago was tied to an intensely positive or negative experience), then they were much more likely to recall the whole song perfectly.

Earworms

Earworms are those songs that get stuck in your head, and you just can’t seem to shake them!  This can be very frustrating, and it is typically the simplest (and most annoying) songs too!  I’m sure you all can find ways to “take your mind off” something you don’t want to h about.  You basically replace the thoughts by distracting yourself with other thoughts.  But it’s not so simple to get rid of these songs.  Schulkind theorizes that this means musical recall must be supported b a different part of the brain than other types of thinking and memory.

Music And Lost Memories

Schulkind’s studies on using music to retrieve long term memory found, in at least one of his experiments, that listening to music from your past can certainly help recover “lost” memories, even in patients with dementia (like Alzheimer’s).   This seems to indicate that part of the memory problems with dementia is recovery – the memories are still there, but the access to them is hampered.

Human Brain Memory long term memory, music