Improving Memory with Magnets?

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

Scientists at the university of Sydney in Australia have recently claimed to be able to make people’s memory more accurate by reducing the occurrence of false memories… via magnets.

Although it is often possible to increase the precision of memory by paying better attention at the time of an event, little till now has been able to help improve remembrance after the fact.

The experimenters used electro-magnetic pulses via a technique called transcranial magnetic stimulation to decrease brain activity in such a way as to mimic the minds of people with anterior temporal lobe dementia and autism.  The logic behind this being that one of the common characteristics of these conditions is a more literal memory with greater accuracy for details.

Participants were given a list of words to memorize and then either actual magnetic brain manipulation, a sham manipulation or no treatment at all.

Those who actually had their brains magnetically pulsed after seeing the list of words showed a 36% decrease in false memories, meaning thinking a word was initially presented when it was not, over those whose brains were left untouched.

Although this leaves us with more questions than answers, the authors point to a possible future application in the courtroom, where memories frequently get a little too creative.

Reference:

Gallate, J., Chi, R., Ellwood, S., & Snyder, A. (2009). Reducing false memories by magnetic pulse stimulation. Neuroscience Letters, 449(3), 151-154. doi: 10.1016/j.neulet.2008.11.021.

Staying Sharp by Keeping Fit

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and science writer for Lumos Labs.

It turns out there may be a link between cardiovascular fitness and the size of one’s hippocampus, a portion of the brain important for the formation of new memories.

Researchers from the University of Illinois and the University of Pittsburgh, looked at the cardiovascular fitness of 165 adults between the ages of 59 and 81. They also measured (via MRI) the size of each participant’s hippocampus and tested for spatial reasoning abilities.

What they found:

• Elderly adults who are physically fit tend to have larger hippocampi than those who are less fit.
• Having a larger hippocampus is correlated with better performance on spatial memory tasks.

Exercise has been linked to hippocampus size and spatial memory in rodents, but this is the first study to demonstrate a similar relationship in humans.

This is good news because although variable between individuals, it is well established that the hippocampus typically shrinks with age and that this shrinkage is associated with subtle but definite declines in memory and spatial orientation.

References:

Erickson, K. I., Prakash, R. S., Voss, M. W., Chaddock, L., Hu, L., Morris, K. S., et al. (2009). Aerobic fitness is associated with hippocampal volume in elderly humans. Hippocampus.

Kitabatake, Y., Sailor, K. A., Ming, G., & Song, H. (2007). Adult neurogenesis and hippocampal memory function: new cells, more plasticity, new memories? Neurosurgery Clinics of North America, 18(1), 105-13, x.

Trying too hard to focus

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and science writer for Lumos Labs .

A new study indicates that focusing too much might actually diminish your ability to pay attention. The researchers, based out of Carnegie Mellon University, used a phenomenon called the attentional blink as the center of their investigation.

An attentional blink is a deficit in visual attention which often occurs 200-500 milliseconds after the first of two visual items are presented during an experiment. The study looked at the ability of participants to detect that second visual item in the presence of visual distractions (moving grey dots).

Surprisingly, the distractors enhanced the ability of people to detect items often obscured by attentional blinks.

The authors hypothesize that the attentional blink phenomenon is due to an overexertion of control happening when target detection and memory consolidation overlap.

They surmise that the adding of distractors dissipates this overexertion of control, thereby enhancing performance.

So the next time you’re playing Speed Match you may want to try day dreaming a bit…it just might improve your score.

References:
Taatgen, N. A., Juvina, I., Schipper, M., Borst, J. P., & Martens, S. (n.d.). Too much control can hurt: A threaded cognition model of the attentional blink. Cognitive Psychology, In Press, Corrected Proof.

Salvucci, D. D., & Taatgen, N. A. (2008). Threaded cognition: An integrated theory of concurrent multitasking. Psychological
Review, 115(1), 101–130.

Lumosity for your future offspring?

Could the brain training you do today help the memory of your children – even before conception? Research published today suggests that – surprisingly – this might actually be possible.

A study of brain function in mice reveals that a stimulating environment improves the memory of their offspring. If this improvement also occurs in humans, a mother’s youthful experiences may help shape her childrens’ ability to learn. Here’s the press release, with the paper reference below the fold:

Newswise — A study reveals that the severity of learning disorders may
depend not only on the child’s environment but also – remarkably – on
the mother’s environment when she was young. The study in
memory-deficient mice, published in the February 4 issue of The
Journal of Neuroscience, was led by Larry Feig, PhD, professor of
biochemistry at Tufts University School of Medicine and member of the
biochemistry and neuroscience programs at the Sackler School of
Graduate Biomedical Sciences at Tufts University.

The researchers studied the brain function of pre-adolescent mice with
a genetically-created defect in memory. When these young mice were
enriched by exposure to a stimulating environment – including novel
objects, opportunities for social interaction and voluntary exercise –
for two weeks, the memory defect was reversed. The work showed that
this enhancement was remarkably long-lasting because it was passed on
to the offspring even though the offspring had the same genetic
mutation and were never exposed to an enriched environment.

Previous research has shown that environmental exposures during
pregnancy can affect offspring. “A striking feature of this study is
that enrichment took place during pre-adolescence, months before the
mice were even fertile, yet the effect reached into the next
generation,” said Feig.

“The offsprings’ improved memory was not the result of better
nurturing by mothers who were enriched when they were young. When the
offspring were raised by non-enriched foster mothers, the offspring
maintained the beneficial effect,” said co-author Junko Arai, PhD,
postdoctoral associate in Feig’s laboratory.

“The effect lasted until adolescence, when it waned, suggesting that
this process is designed specifically to aid the young brain,”
continued Shaomin Li, PhD, MD, co-author, former postdoctoral
associate in Feig’s laboratory, now at Brigham and Women’s Hospital.

“This example of ‘inheritance of acquired characters,’ was first
proposed by Lamarck in the early 1800s. However, it is incompatible
with classical Mendelian genetics, which states that we inherit
qualities from our parents through specific DNA sequences they
inherited from their parents. We now refer to this type of inheritance
as epigenetics, which involves environmentally-induced changes in the
structure of DNA and the chromosomes in which DNA resides that are
passed on to offspring,” said Feig.

Previous research by Feig and his team showed that a relatively brief
exposure to an enriched environment in both normal and
memory-deficient mice unlocks an otherwise latent biochemical control
mechanism that enhances a cellular process in nerve cells called
long-term potentiation (LTP), which is known to be involved in
learning and memory. This enhancement was detected in pre-adolescent
mice but not in adult mice, reflecting the brain’s higher plasticity
in the young.

Feig concluded that the transgenerational inheritance of the effect of
an enriched environment may be a mechanism that has evolved to protect
one’s offspring from deleterious effects of sensory deprivation, which
may be particularly potent in the young and exacerbated in the
learning disabled.

Junko Arai and Shaomin Li, first authors, contributed equally to the
paper. Dean M. Hartley, PhD, of Rush University Medical Center is also
an author.

The work was supported by the National Cancer Institute of the
National Institutes of Health because these findings were derived as
an offshoot of the Feig lab’s long-term experience working on Ras
proteins that are involved in cancer. Fundamental principles of how
Ras proteins function gained by studying its role in cancer expedited
subsequent studies on Ras function in the brain. This work highlights
how major breakthroughs can arise by allowing researches to follow new
leads that cross disciplines. The work was also supported by the Tufts
Center for Neuroscience Research.

Arai J, Li S, Hartley DM, and Feig LA. The Journal of Neuroscience.
2009. (February 4); 29(5): 1496-1502. “Transgenerational Rescue of a
Genetic Defect in Long-Term Potentiation and Memory Formation by
Juvenile Enrichment.” Published online February 3, 2009, doi:
10.1523/JNEUROSCI.5057-08.2009

About Tufts University School of Medicine
Tufts University School of Medicine and the Sackler School of Graduate
Biomedical Sciences at Tufts University are international leaders in
innovative medical education and advanced research. The School of
Medicine and the Sackler School are renowned for excellence in
education in general medicine, special combined degree programs in
business, health management, public health, bioengineering, and
international relations, as well as basic and clinical research at the
cellular and molecular level. Ranked among the top in the nation, the
School of Medicine is affiliated with six major teaching hospitals and
more than 30 health care facilities. The Sackler School undertakes
research that is consistently rated among the highest in the nation
for its impact on the advancement of medical science.

Your Nervous System at Work

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

Ever wonder about the workings of your nervous system?  As mentioned in our previous post on cognition, the nervous system is responsible for integrating and processing information about your surroundings while directing action towards the achievement of goals; whether this be eating a tuna sandwich, serenading a lover or getting out of the way of a speeding bus. Physically, it is made up of your brain, spinal cord and peripheral nerves.

Let’s look at the structural components of this biological orchestra.

Neurons and Glia
The basic functional units of the nervous system include neurons (cells who’s primary job is to communicate) and glia (cells which support neurons and their communication).

The average brain has about 100 billion neurons and about 9 times as many glia.

Neurons (with the help of glia) connect and coordinate senses such as sight, hearing, smell, touch and taste with the activity of your muscles and organs. They are either taking information in for integration, communicating with other neurons for information processing, or sending information out to generate action.

Glial cells (of which there are multiple types) do a variety of tasks to support the functioning of neurons, including removing waste, providing nutritional and structural support and facilitating connections. Some glia have also been shown to communicate with neurons, as well as each other, in order to help coordinate neuronal activity.

Synapses and Neurotransmitters
Synapses are the actual locations at which neurons communicate with each other, and a typical neuron has about 10,000 of them.

Neurons communicate at synapses through the use of neurotransmitters. Neurotransmitters are chemicals sent between neurons as well as the muscles and organs they work with. They attach to receptors on receiving cells, translating into one of three basic types of messages:

•    Excitatory- Encouraging connected neurons and other related cells to “pass it on” or activate; perhaps prompting you to swat at that fly after being buzzed by the umpteenth time or dilate your pupils when the lights go out.

•    Inhibitory- Suggesting that the receiving cell not continue passing on the signal or take action. This could be involved in the shutting down of appetite in response to the non-acquired taste of anchovies or the ability to ignore the radio in your car while figuring out how to get un-lost.

• Adaptive- Instructing a neuron to change something in its structure or the way it functions. This is the basis of plasticity where neurons may reduce or increase the number of connections, move them around and or adjust their sensitivity; all of which are part of the learning process.

Neural Networks

Neurons which collaborate on a specific physiological function, such as hearing high pitches, moving your pinky or remembering to take the trash out, are considered to be part of a shared neural network. Typically these functionally related neurons will use only one or two of the over 100 different types of neurotransmitters available. Neurotransmitters, however, can and often are associated with several types of neural networks.

Serotonin is an example of a neurotransmitter involved with the regulation of multiple systems including mood, appetite, temperature, pain sensation and sleep.

Dopamine is the neurotransmitter of choice for neural networks dealing with reward, such as the feeling you get after winning an egg toss or eating a delicious meal. It is however also used by circuits involving memory and attention.

Complexity
As much as we do know about how our nervous systems work, there is still much more to be discovered. One of the many areas where little is known involves how different neural networks, responsible for such diverse tasks as detecting movement, recognizing objects and generating action, can communicate between themselves. The mechanisms involved in coordinating the information from different specialized neural systems into a seamless experience of say, catching a ball, is still a mystery.  This is referred to as the binding problem, and although there are plenty of theories, there are no clear answers as of yet.

As you can see, the interactions between our neurons, neurotransmitters and constantly shifting surroundings are complex…..especially when they are trying to grasp the complexity of interactions between neurons, neurotransmitters and constantly shifting surroundings;)

Musicians, Creativity and Balanced Brain Use

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

Research just published in the journal Brain and Cognition suggests that musical training can lead to more creative thinking and more symmetrical brain activity. The investigators, based out of Vanderbilt University in Nashville Tennessee, ran two experiments both comparing 20 musicians (with a minimum of 8 years of musical experience) with 20 non-musicians.

The first looked at potential differences in creative abilities by asking participants to come up with as many novel uses of common household items as possible, followed by their completing a word association task.

The second study monitored brain blood flow via near infrared spectroscopy (NIRS) while participants again generated as many novel uses of everyday objects as possible.

The data indicated that:

• On average the musicians were able to generate about 13 more examples of how to use common objects than non-musicians.
• The musicians performed better on the word association task, producing an average of approximately 9 more correct responses than their non-musical counter parts.
• Overall, during the creative tasks, musicians showed more symmetrical brain blood flow between the hemispheres than the non-musicians.

Although it is always possible that creative people tend to be more drawn to the world of music than non-creative people, the authors suggest that the results might be due to the ability of certain aspects of music training, such as improvisation and song creation, to enhance cognitive and neural mechanisms of the creative process.

References:

Gibson, C., Folley, B. S., & Park, S. (2008). Enhanced divergent thinking and creativity in musicians: A behavioral and near-infrared spectroscopy study. Brain and Cognition.

What is Cognition?

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

What exactly is cognition and how does it work? Here we will attempt to outline and explain some of the basic concepts involved with the inner workings of your head.

Cognition literally means “to know”.  Knowledge can be thought of as memories formed from the manipulation and assimilation of raw input , perceived via our senses of sight, hearing, taste, touch and smell.

Using knowledge to direct and adapt action towards goals is the foundation of the cognitive process. Past experiences and trends inform our sense of what the future might hold and help us to act accordingly.

Take a yearning for pizza for example… Cognition encompasses everything from knowing/remembering what pizza is (and that you like it)…to realizing that you are hungry and making plans to have it delivered.

In order for our finite minds to make sense of the near infinite details of our surroundings however,  a large part of cognition involves the organization of our thoughts into associations or categories. These might range from “things one might find in a kitchen” to “people I think are cute”. Simple symbols such as the word “face” are used to group more complex learned associations such as those between noses, lips, eyes and smiles.

Although important, these “cognitive categories” are overlapping and not always clearly distinct…so keep this in mind as we break down the concept of cognition itself into some of its more widely recognized pieces.

The words perception, attention, memory and executive function are one way of divvying up the processes involved in how we think. All of the above will be involved throughout your journey towards satisfying that pizza craving. Let’s use some specific points to illustrate their role in the overall process of attaining such a dinner goal.

Perception, in this case, of the fact that you feel hungry and that there is no food in the fridge, is what gets the whole process moving. It involves seeing, hearing, feeling, tasting and or smelling your surroundings, allowing you to respond appropriately.

Memory plays the obvious role of storing the name of your favorite pizza parlor. It also enables you to dial the number given by the operator and give directions to your house. Some different components include short term/working memory, long-term memory and subconscious/implicit knowledge.

Executive Function enables the planning of logistics, such as timing the pizza delivery to coincide with the arrival of your scrabble buddies.  Improvising (guessing what toppings everyone will enjoy), problem solving (figuring how much to tip) and controlling impulses (not ruining your appetite by eating a whole bag of Doritos while waiting) also come into play here.

Attention processes kick in by having you shift your focus from reading the Sunday funnies to answering the door upon hearing that long awaited knock. They also help in multi-tasking a slice of pizza with figuring out how to nail that triple word score all while ignoring the heckling antics of your so called “friends”.

Again, although separated for the purposes of our discussion here, it is the interplay of all of these systems working simultaneously which makes up the process of cognition; allowing us to adapt to our surroundings and take action towards obtaining our goals.

Intelligence training

By Gregory Kellett, a cognitive neuroscience researcher at SFSU and UCSF, and science writer for Lumos Labs.

A study conducted by Martin Buschkuehl and Susanne Jaeggi in John Jonides’ lab at the University of Michigan indicates that it is possible to improve on measures of fluid intelligence by training one’s working memory.

The concept of fluid intelligence (gF) as defined by its founder Raymond Cattell is “…the ability to perceive relationships independent of previous specific practice or instruction concerning those relationships.” Fluid intelligence contributes to abilities like learning and problem solving. It is distinct from its counterpart, crystallized intelligence (cF) which involves  “…abilities that have obviously been acquired, such as verbal and numerical ability, mechanical aptitude, social skills, and so on.”

Fluid intelligence tests usually entail completing visual patterns of some kind.  Performance on such tests typically declines after reaching a peak in early adulthood.  This study, however, offers evidence that it’s possible to improve fluid intelligence, at least temporarily.

The researchers used a computer-based working memory task called the “dual n-back” to simultaneously administer auditory and visual stimuli in sequence.  A response was required whenever one of the presented stimuli (visual or auditory) matched a previously presented stimulus n positions back in the sequence.  Four groups trained daily for either 8, 12, 17 or 19 days, with each group being matched by a control group that did not have training.  Pre and post tests of fluid intelligence were given to all groups.

What the study found:

• The working memory training significantly improved performance on the fluid intelligence tests.
• Fluid intelligence performance improved in proportion to the amount of training received.
• Working memory (as measured by digit span) also improved significantly.

The authors suggest that the above effects were due primarily to an increased ability to control attention.

References:

Cattell, R. B. (1971). Abilities: Their structure, growth, and action. New York: Houghton Mifflin.

Jaeggi, S., Buschkuehl, M., Jonides, J., Perrig, J. (2008). “Improving fluid intelligence with training on working memory.” PNAS- Proceedings of the National Academy of Sciences