Our bodies know when to fall asleep and when to wake up. Our brains can keep track of short bursts of time like a mental stopwatch. But in our memories, our sense of time is fuzzy. Now, research is beginning to uncover how we put our memories in order.
These new insights into the workings of the brain, paired with other findings, could help in the understanding and early detection of diseases such as dementia and Alzheimer’s, scientists say.
So one day in the future this may restore to the brain the episodic memory abilities it had lost, the most common type of memory loss in people with brain injuries or Alzheimer's disease.
The research findings clearly show that it is possible to not just 'read', but also 'write' a person's brain.
The study involved a small number of participants and is still early stage, but the results are definitely significant.
The stimulation did not replace the CA1 activity in the brains during the study, but instead, was complementary to the neural activity.
The patients were also shown a set of three images after a 75-minute delay and were asked to identify the original photo from a set of 4-5 photos. Using stimulation with the correct spatiotemporal codes had resulted in 35% improvement in memory.
The researchers then tested the system to see if it would have a similar effect on long-term memory. The patients had to identify the photos out of a set of photos after a short delay.
Those firing pattern codes for each patient were then translated into electrical stimulation signals, delivered during another visual test. The results showed an average of 37% improvement in memory.
The researchers analyzed firing patterns associated with correct responses to the visual test and created a mathematical model that predicted how the brain would fire when memories were formed successfully.
When the brain encounters new information it needs to encode as a memory, neurons in CA3 region fire away. When the brain needs to retrieve that same information, regions in the CA1 region are activated.
Electrodes were implanted in the CA3 and CA1 regions of the hippocampus, which together support memory encoding and retrieval.
Patients were shown a simple image, such as a color block. Then, shortly afterwards they were shown a set of multiple images and asked to pick out the one they had been first shown.
In this study, the researchers surgically implanted electrodes to record neuronal activity in regions of the hippocampus, while the patients performed a visual memory test.
Epilepsy patients are often subject to memory loss, and brain-computer interface research is used as part of their treatment, with electrodes to monitor seizure patterns.
The research was funded by DARPA, as part of the Restoring Active Memory (RAM) program. The researchers worked with 15 patients being treated for epilepsy.
Researchers from Wake Forest Baptist Medical Center and the University of Southern California reported in the 'Journal of Neural Engineering' in March 2018 the first successful implementation in humans of a proof-of-concept system for restoring memory function.
“We are now able to monitor when the brain seems to be going off course and to use stimulation to correct the trajectory.' said Dr. Michael Sperling, clinical study investigator at Thomas Jefferson University Hospital.
said Dr. Youssef Ezzyat, data scientist at Psychology Department at Pennsylvania University, lead author of the research study.
“During each new word the patient viewed, the system would record and analyze brain activity to predict whether the patient had learned it effectively. When the system detected ineffective learning, that triggered stimulation, closing the loop.”
Each patient performed the free-recall memory task during at least three 45-minute sessions before any closed-loop stimulation, to make sure that the brain activity linked to ineffective learning reflected a true pattern and at least one session involving brain stimulation.
Each patient participated in a delayed free-recall task in which they had to study lists of words for a later memory test. No encoding task was used. The lists were composed of 12 words each, chosen at random and without replacement from a pool of often employed English nouns.
Dartmouth-Hitchcock Medical Center and Mayo Clinic. All patients had electrodes implanted in their brains as part of the routine clinical treatment for epilepsy.
The study involved 25 neurosurgical patients treated for epilepsy, who participated at clinical sites including the Hospital of the University of Pennsylvania, Thomas Jefferson University Hospital, University of Texas Southwestern, Emory University Hospital,
While the patient watched a list of words and tried to remember it, a computer tracking and recording brain signals made predictions based on those signals and then prompted an electrical pulse, unfelt by the participants, when they were least likely to remember new information.
The brain activity of any patient was monitored in real time, during a task performance.
The neuroscientists developed a system aimed to monitor brain activity and to trigger stimulation selectively, based on the patient’s brain activity. The target for applying stimulation was the left lateral temporal cortex.
The research is part of the Restoring Active Memory (RAM) project of DARPA, targeted at developing next-generation technologies capable to improve memory in veterans with memory loss.
Targeted stimulation to lateral temporal cortex rescues periods of poor memory encoding and also improves later recall, making the lateral temporal cortex is a reliable target for memory enhancement.
Memory failures are frustrating and often the result of ineffective encoding. One approach to improving memory outcomes is through direct modulation of brain activity with electrical stimulation.
Precisely timed brain stimulation to the left side of the brain can enhance learning and memory performance by about 15%, innovative research from University of Pennsylvania published in 'Nature Communications' in February 2018 reveals.
Such systems might provide a therapeutic approach for treating memory dysfunction in the future.
In 2013 DARPA launched the Restoring Active Memory (RAM) program, aimed to create an implantable brain-computer interface able of restoring normal memory activity to people suffering from brain injury or mental illness.
This groundbreaking research of the navigation system in brain has opened new avenues for studying how cognitive processes are computed in the brain.
The discoveries of place and grid cells by Dr. John O’Keefe, Dr. May-Britt Moser and Dr. Edvard I. Moser represent a fundamental shift in the understanding of how groups of specialized cells in the brain work together to execute higher cognitive functions.
The hippocampus is one of the first structures to be affected in Alzheimer’s disease and knowledge about the brain’s navigational system might help understand the cognitive decline seen in patients with these diseases.
In brain disorders, such as dementia and Alzheimer’s disease the episodic memory is affected. Dr. O’Keefe and collaborators have showed in a mouse model of Alzheimer’s disease that the degradation of place fields correlated with the deterioration of the spatial memory.
As well, the taxi drivers after the training had significantly larger hippocampus volume than other people.
It turns out that the hippocampus of London taxi drivers, which undergoes extensive training to learn how to navigate between many places in the city without a map, grew during the year long training period.
The activity of place cells may be used to define the position in the environment at any given time, and also to remember past experiences of the environment.
This replay of place cell activity during sleep may be a memory consolidation mechanism, where the memory is eventually stored in cortical structures.
After a memory has been encoded, the memory undergoes consolidation, for example during sleep. Groups of place cells that are activated in a particular sequence during the event, display the same sequence of activation in episodes during the subsequent sleep.
An encoding of places in the past and present might allow the brain to remember temporally ordered representations of events, like in the episodic memory.
There is no direct evidence that place cells are coding episodic memory. However, place cells can encode not only for the current spatial location, but also where the animal has just been and where it is going next.
The initial discovery of place and grid cells was in mice. But many mammalian animal species including humans share the same systems.
* The patient had lost what has been later called 'the episodic memory', related to the ability to remember self-experienced events.
In the 1950s an epilepsy patient had the hippocampus surgically removed, and this caused to severe memory deficits, and also to the inability to encode new memories, while he could still retrieve old memories.
Place-coding cells in the hippocampus structures are involved in the storing and the retrieving of spatial memories.
In a first study they established that the medial entorhinal cortex contained cells that shared characteristics with the place cells in hippocampus. In a later study they discovered a new cell type, the grid cells.
With these findings in mind and with the knowledge that medial entorhinal cortex is also directly connected to the CA1 region, Dr. May-Britt Moser and Dr. Edvard Moser thought to look in the medial entorhinal cortex for place coding cells.
In 2002, Dr. May-Britt Moser and Dr. Edvard Moser found that disconnecting projections from the entorhinal cortex through CA3 did not invalidate the CA1 place fields.
A big part of the output from the entorhinal cortex projects to the dentate gurus in hippocampus, which in turn connects to the region in the hippocampus called CA3, and then to CA1 in the dorsal hippocampus, the part of the brain in which Dr. John O’Keefe found the place cells.
The major input to the hippocampus comes from the entorhinal cortex, a structure on the dorsal edge of the brain.
Through the 1980s and 1990s the prevailing theory was that the formation of place fields originated within the hippocampus. Dr. May-Britt Moser and Dr. Edvard Moser suspected that the place cell firing can be generated from activity outside the hippocampus.
The place cells may provide a cellular platform for memory processes, where a memory of an environment can be stored as specific combinations of place cells.
In further experiments, Dr. John O’Keefe showed that the place cells might have memory functions, that the reorganization or remapping of place cells is learned, and once it is established, it can be stable over time.
This research enabled him to relate the neural activity in the place cells to the sense of place.
Working at University College in London, in 1971 Dr. John O’Keefe discovered place cells, when recording information from neurons in the dorsal partition of hippocampus, called CA1, in rats moving freely in a bounded area.
Together, the place cells in the hippocampus and the grid cells in the medial entorhinal cortex create interconnected neuron networks that are critical for the performance of navigational tasks.
Dr. May-Britt Moser and Dr. Edvard Moser discovered in the medial entorhinal cortex, a region of the brain next to hippocampus, grid cells that provide the brain with an internal coordinate system essential for navigation.
Dr. John O’Keefe discovered place cells in the hippocampus that signal position and provide the brain with spatial memory capacity.
The 2014 Nobel Prize in Medicine was awarded to Dr. John M. O’Keefe, Dr. May-Britt Moser and Dr. Edvard Moser for their groundbreaking discoveries of brain cells that enable a sense of place and navigation.
The hippocampus is critical for the conversion of certain short-term scratch-pad memories into permanent memories.
The hippocampus is where new neurons are born in adult people.
The hippocampus is a major memory structure and regulator and that's why a damaged hippocampus would generate learning disabilities, poor school performance, weak work performance and many other developmental problems.
The hippocampus is a key element in the formation of long-term memory, responsible for the integration of different kinds of information, associations between things, the ability to understand cause-effect relationships, and the ability to understand links between occurrences.
For example, taxi drivers have a bigger posterior area in hippocampus than bus drivers, because this region is specialized with acquiring special information needed to navigate through the city streets, while bus drivers have a limited and constant set of routes to remember.
Skilled learning of abstract information or technologies also triggers plastic changes in the brain.
The cortex volume is highest in professional musicians, intermediate in amateur musicians, and lowest in non-musicians in several brain areas involved in playing music: motor regions, anterior superior parietal areas and inferior temporal areas.
Plastic changes also occur in musicians brains compared to non-musicians.
Bilinguals - people learning a second language - have functional changes in the brain. Their left inferior parietal cortex responsible with language learning is larger than in monolingual people brains.
Research shows that when someone becomes an expert in a specific domain, the areas in his brain dealing with that type of skill grow.
And the survival of the new neurons depends on their ability to make functional connections with existing neurons. If new neurons fail to integrate into existing neural networks they will die.
The truth is that new neurons live according to the mantra 'Use us or lose us!' They die unless they are actively used.
Research shows that new neurons grow in the brain at any time and at any age, when associated with learning. But continuous learning and practice are critical.
Research comparing images of the brains of medical students learning for their medical exam and right after the exam showed learning-induced changes in regions of the parietal cortex as well as in the posterior hippocampus, regions involved in memory retrieval and learning.
Skilled learning of abstract information or technologies triggers plastic changes in the brain.
Knowing how to learn is extremely positive and powerful, and has huge implications for students of any age and also for aging adults who need to maintain their brain healthy. It also has a significant influence on our actual memory capacity.
Our intelligence is not fixed and we can change it. And our brain memory could store much more – 10 times more - information than was thought possible in the past.
What happens in our brain when we learn?
RT : New research on how the brain orders our memories could have implications for ...
Brain mean blood, cells, neuves, bones, all the life elements but how is work? Our spirit & souls, human don't possess any kinds of understanding knowledge to our brain? But imagine lots This tweets chat look like basically cold war so I don't want any more regards cold war
Except the research is wrong! The brain is controlled by the MIND, and NEVER the reverse.
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