Transcranial Magnetic Stimulation Found To Improve Memory

(c) Copyright: EPFL, Blue Brain Project

A study by the Northwestern University Feinberg School of Medicine find that stimulating a part of the brain with electromagnetic pulses in a process called Transcranial Magnetic Stimulation can improve memory.

The non-invasive process uses electrical current using magnetic pulses to target a region of the brain. This is the first time that memory functions of a brain can be manipulated without the use of surgery or of drugs.

By targeting a specific area of the brain in the hippocampus, they observed that TMS can be used to improve memory for events at least 24 hours after the stimulation is given.

The study, published in Science, used 16 healthy adults ages 21 to 40 (see video below). They received brain stimulation through Transcranial Magnetic Stimulation (TMS) twenty minutes a day for five consecutive days. It was noted that the group performed better on memory tests as a result of the brain stimulation and that it took three days of TMS before they improved.

Neurostimulation is a process where neurons in the nervous system are stimulated to either restore functionality of a certain organ, control an organ, or induce/reduce a specific nerve signal within the system. This is done through micro-electrodes that deliver electrical signals to the neurons.

There are four types of neurostimulation; Brain Stimulation, Deep Brain Stimulation (DBS), Transcranial Magnetic Stimulation (TMS), and Spinal Cord Stimulation (SCS). Each of these types have been used to alter/improve brain activity in the past.

This recent discovery is the first to show how electrical stimulation can improve new learning long after treatment and may help treat memory disorders resulting from stroke, Alzheimer's Disease and other types of brain injury.

Working Memory - Studying How The Brain Performs Tasks Based On Memory

Credit: Badre Lab/Brown University

Using Magnetic Resonance Imaging (MRI), researchers at Brown University released a study on how the brain, using working memory, chooses and plans a course of action or task or a series of task.

Similar to short term memory, working memory is a form of memory that keeps and uses information to complete a task or course of action. Working memory is stored in the brain for a limited amount of time; enough time to organize, plan, and execute the task.

The researchers at Brown measured the reaction time of 22 adult volunteers on how the receive, process, and execute a task using working memory. They find that the brain uses an area of the brain called the Caudate and the prefrontal cortex centered on the dorsal anterior premotor cortex. The image above shows the dorsal anterior premotor cortex lit up by MRI.

They also note that working memory uses similar uses similar circuits to those involved in planning motion.

Studying how working memory works helps in understanding brain cognition and also in finding how these parts of the brain affect behavior.

The Brain Rewrites and Edits Memories

A Northwestern Medicine study shows that memory is not as accurate as people might think. The study revealed that the brain rewrites stored memory infusing it with things from the present.

By conducting memory experiments on 17 men and women, the team used computers and an MRI scanner to observe how the brain worked during the experiment. They specifically show that memory is faulty, and that the brain can insert things from the present into past memories when those memories are retrieved. The study shows the exact point in time when that incorrectly recalled information gets implanted into an existing memory.

They also have observed that the hippocampus is the part of the brain when memory manipulation happens.

The purpose of memory, they note, is to assist in making a decision or reacting to a situation to better deal with it. The brain inserts present things not originally in the actual memory to make it more relevant to the current situation.

New Process Developed To Image How The Brain Forms Memories

Researchers at Albert Einstein College of Medicine of Yeshiva University have imaged the brain while forming memories on the molecular level. This was achieved by tagging fluorescent beta-actin mRNA molecules using a mouse model.

The tagged molecules were observed by the scientists in real time while brain cells were forming memories. See embedded video.

They note that the stimulated individual hippocampal neurons caused a rapid transcription of the beta-actin gene within 10 to 15 minutes. The hippocampus is the region of the brain where where memories are made and stored. These beta-actin mRNA molecules continuously assemble and disassemble into large and small particles, respectively. These mRNA particles were seen traveling to their destinations in dendrites where beta-actin protein would be synthesized.

The neurons connect to each other through spines of dendrites where long-lasting synaptic connections form between neurons in contact with each other. The Beta-actin protein appears to strengthen these synaptic connections by altering the shape of dendritic spines.

Time and Brain Coordination Improves Memory Preservation.and Reduces Forgetfulness

Credit: Smithsonian, Photo Researchers, Inc.

Neuroscientist have discovered that coordinated brain activity increases with time after memory formation which results in better memory preservation.

Memory formation in the brain is processed in three stages; encoding, storing, and retrieving. In the encoding stage, information is transformed or encoded by the brain through chemical and electrical signals. Information is then stored in different regions of the brain depending on its type. The retrieval process brings these stored memories into conscious awareness.

The actual process of how memories are formed, stored and then retrieved is still not fully understood.

In this new study, neuroscientists have found that brain coordination during the memory process gets better as time goes by. In their experiment, they noted that a newly formed memory in the test subjects is strengthened when the whole process is reapplied the next day.

Imaging Neurons While New Memories Are Formed Using mRNA Display and Microscopic FingRs Probes

Scientists have, for the first time, imaged neurons while new memories are being formed. This was done by using fluorescent markers on the synaptic proteins connected to the neurons. The scientists also developed microscopic probes called FingRs as well as a tracking technique, mRNA Display, to find and visualize the neurons during the memory formation process.

Neurons are the cells responsible for transmitting information to and from the brain. It is the core component of the nervous system. Each of these neurons are interconnected through synapses. Synapses are structures similar in function to telephone cables, that allow the passing of electrical or chemical signals between the neurons.

The image on the left (courtesy of Don Arnold), shows a living neuron in culture. The green dots indicate the excitatory synapses and the red dots indicate inhibitory synapses. An excitatory synapse is a synapse that increases the chance of an action potential occurring in a postsynaptic cell. An inhibitory synapse is the opposite, it decreases the chance of an action potential.

Neurons need a lot of the body's resources to perform efficiently. The metabolic requirements for these require about 15% of the output of the heart (cardiac output), 20% of the body's oxygen consumption, and 25% of the body's glucose utilization. The brain only takes energy from glucose.

There are about 80 to 100 billion neurons in the human brain. And there are about 100 trillion synapses connecting the neurons together. Looking at a portion of the brain, the size of a pinhead, one would find around 30,000 neurons in it.

The most number of neurons a person could ever have is during the first trimester as a fetus. Neurons are not made or replaced during one's life. Current developments in medicine have shown that neurons can be made and repaired using stem cell technology.

Clenching Fists Can Help Form Stronger Memories and Also In Recollecting Them

In a paper published in PLOS ONE, researchers at the Montclair State University found in their study that clenching fists can help form and recollect memory. In their paper, they observed that clenching the right fist can help in forming stronger memory and clenching the left fist can aid in recollecting them.

Finding ways to improving memory has been a popular practice specially with older people. As one ages, the ability to form and retain memory reduces. In a related article, The Memory Toolbox, memory loss is attributed to stress. Stress affects the way the brain processes information in a way that memory can be impaired or not even be retained.

Within the brain, the frontal lobe is attributed in retaining long term memories. These are memories that are not task based (like driving a car) but are those associated with emotions. The Montclair study suggests that some body movements affect the way the brain processes certain tasks such as improving memory.

There are a lot of techniques that are used to improve memory (75 are listed in The Memory Toolbox). Imaging technologies such as MRI (Magnetic Resonance Imaging) and fMRI (functional MRI) have also contributed to studying and observing brain activity in relation to how it processes information.

How Nerve Cell Activity Between Neurons is Regulated Within the Brain's Hippocampus

Scientists have discovered the process on how the synapses regulate nerve cell activity when communicating with each other. Neuronal activity within the hippocampus must be maintained at a steady and optimal level since over activity can cause seizures while the opposite can cause degradation of neural cells as well as impair information.

The brain is made up of four major parts. The cerebrum, the cerebellum,the brain stem, and the limbic system which contains the hippocampus. These major parts are responsible for different functions of the brain from feeling emotion, decision making, and even breathing.

The cerebrum is responsible for memory, problem solving, thinking, movement, and feeling. It is located at the front part of the brain. The cerebellum, which can be found at the back is responsible for balance and coordination. The brain stem located at the bottom of the brain, is responsible for the autonomic nervous system. These are processes that are below the conscious level such as breathing, digestion, and even heart rate.

The limbic system which is the learning and emotional part of the brain is made up of the thalamus, hypothalamus, amygdala, and hippocampus. It can be found buried within the cerebrum.

Hippocampus is latin for seahorse since the organ resembles a seahorse (see image). The hippocampus is responsible for the consolidation of memory, both short term and long term. It is also part of the limbic system that primarily deals with emotion, behavior, motivation, long-term memory, and olfaction (sense of smell). It also plays a role in spatial thinking, which relates to determining location within the environment.

Humans have two hippocampi situated on the left and right side of the brain.

Using fMRI To Examine Brain Activity In Forgetting Memories Through Suppression And Substitution

Two neurologists used functional magnetic resonance imaging (fMRI) to examine the brain activity when volunteers attempt to forget memories by either blocking them out or recalling substitute memories.

Roland Benoit and Michael Anderson of the MRC Cognition and Brain Sciences Unit at the University of Cambridge found that these two mechanisms, substitution and suppression, are how the brain voluntary forget specific memories. This finding can lead to the development of treatments to improve disorders of memory control.

Mental and Physical Stimulation During Old Age Show Better Cognitive Performance And A Younger Brain

When a person ages, there is a decline in memory functions. This is called Age Related Memory Impairment (AMI) or Age Associated Memory Impairment (AAMI). There is difficulty in making new memories and working memory declines.

There are two major kinds of memory. Declarative memory and Procedural Memory.

Declarative memory refers to memories which can be consciously recalled such as facts and knowledge (country of birth, name of school). Procedural memory is memory for how to do things like driving a car.

The types of memories most likely to be affected are:

• Episodic memory - memory of experienced events (times, places, associated emotions, and other contextual knowledge) that can be explicitly stated (ex.the first kiss).
• Semantic memory - Memory derived from meanings, understandings, and other concept-based knowledge unrelated to specific experiences (ex. Knowing that rocks are not edible).
• Short term memory - Memory that holds a small amount of information readily available for a short period of time (ex. a dictated phone number).
• Priming - an effect on implicit memory which is a type of memory in which previous experiences aid in the performance of a task without conscious awareness of these previous experiences. Priming is similar to conditioning the brain to associate a word or image through subconscious or indirect means.

Out of these types, episodic memory is the most impaired in normal aging as well as short term memory. These impairments may be related to the brains decreased ability to gather information together during the encoding of the memory as well as its retrieving the associations later.

With old age, source information also declines. Source information is knowledge that includes where and when the information is learned. The ability to recollect the source and context of information is very important in daily decision-making. An example is the ability to recollect why one product or brand is more preferred than the other, why it is preferred, and how that information came to be.

Maintain your brain: The secrets to aging success

Aging may seem unavoidable, but that's not necessarily so when it comes to the brain. So say researchers in the April 27th issue of the Cell Press journal Trends in Cognitive Sciences explaining that it is what you do in old age that matters more when it comes to maintaining a youthful brain not what you did earlier in life.

"Although some memory functions do tend to decline as we get older, several elderly show well preserved functioning and this is related to a well-preserved, youth-like brain," says Lars Nyberg of Umeå University in Sweden.

Continuous Sleep Favorable In Long Term Memory Consolidation and Enhancement

Memory Consolidation is a process where the brain stabilizes a memory trace after the initial acquisition. Memory is usually acquired during conscious periods through learning or experience.

Consolidation is distinguished into two specific processes, synaptic consolidation, which occurs within the first few hours after learning, and system consolidation, where hippocampus-dependent memories become independent of the hippocampus over a period of weeks to years. Recently, a third process has become the focus of research, reconsolidation, in which previously consolidated memories can be made labile again through reactivation of the memory trace.

Based on studies and observation, rapid eye movement (REM) sleep is crucial in the overnight learning in humans by the re-organization of novel information in the hippocampal and cortical regions of the brain. REM sleep elicits an increase in neuronal activity following an enriched or novel waking experience, thus increasing neuronal plasticity and therefore playing an essential role in the consolidation of memories.

Sleep disturbance negatively impacts the memory consolidation and enhancement that usually occurs with a good night's sleep, according to a study published in the open access journal PLoS ONE.

In their abstract, the authors state, "A growing literature supports a role for sleep after training in long-term memory consolidation and enhancement. Consequently, interrupted sleep should result in cognitive deficits. Recent evidence from an animal study indeed showed that optimal memory consolidation during sleep requires a certain amount of uninterrupted sleep. Sleep continuity is disrupted in various medical disorders."