#memory
Trains in the Brain—Scientists Uncover Switching System Used in Information Processing and Memory
A team of scientists has uncovered a system in the brain used in the processing of information and in the storing of memories—akin to how railroad switches control a train’s destination. The findings offer new insights into how the brain functions.
“Researchers have sought to identify neural circuits that have specialized functions, but there are simply too many tasks the brain performs for each circuit to have its own purpose,” explains André Fenton, a professor of neural science at New York University and the senior author of the study, which appears in the journal Cell Reports. “Our results reveal how the same circuit takes on more than one function. The brain diverts ‘trains’ of neural activity from encoding our experiences to recalling them, showing that the same circuits have a role in both information processing and in memory.”
This newly discovered dynamic shows how the brain functions more efficiently than previously realized.
“When the same circuit performs more than one function, synergistic, creative, and economic interactions become possible,” Fenton adds.
To explore the role of brain circuits, the researchers examined the hippocampus—a brain structure long known to play a significant role in memory—in mice. They investigated how the mouse hippocampus switches from encoding the current location to recollecting a remote location. Here, mice navigated a surface and received a mild shock if they touched certain areas, prompting the encoding of information. When the mice subsequently returned to this surface, they avoided the area where they’d previously received the shock–evidence that memory influenced their movement. The analysis of neural activity revealed a switching in the hippocampus. Specifically, the scientists found that a certain type of activity pattern in the population of neurons known as a dentate spike, which originates from the medial entorhinal cortex (DSM), served to coordinate changes in brain function.
“Railway switches control each train’s destination, whereas dentate spikes switch hippocampus information processing from encoding to recollection,” observes Fenton. “Like a railway switch diverts a train, this dentate spike event diverts thoughts from the present to the past.”
Remember more by taking breaks
We remember things longer if we take breaks during learning, referred to as the spacing effect. Scientists at the Max Planck Institute of Neurobiology gained deeper insight into the neuronal basis for this phenomenon in mice. With longer intervals between learning repetitions, mice reuse more of the same neurons as before – instead of activating different ones. Possibly, this allows the neuronal connections to strengthen with each learning event, such that knowledge is stored for a longer time.
Many of us have experienced the following: the day before an exam, we try to cram a huge amount of information into our brain. But just as quickly as we acquired it, the knowledge we have painstakingly gained is gone again. The good news is that we can counteract this forgetting. With expanded time intervals between individual learning events, we retain the knowledge for a longer time.
But what happens in the brain during the spacing effect, and why is taking breaks so beneficial for our memory? It is generally thought that during learning, neurons are activated and form new connections. In this way, the learned knowledge is stored and can be retrieved by reactivating the same set of neurons. However, we still know very little about how pauses positively influence this process – even though the spacing effect was described more than a century ago and occurs in almost all animals.
Learning in a maze
Annet Glas and Pieter Goltstein, neurobiologists in the team of Mark Hübener and Tobias Bonhoeffer, investigated this phenomenon in mice. To do this, the animals had to remember the position of a hidden chocolate piece in a maze. On three consecutive opportunities, they were allowed to explore the maze and find their reward – including pauses of varying lengths. “Mice that were trained with the longer intervals between learning phases were not able to remember the position of the chocolate as quickly,” explains Annet Glas. “But on the next day, the longer the pauses, the better was the mice’s memory.”
During the maze test, the researchers additionally measured the activity of neurons in the prefrontal cortex. This brain region is of particular interest for learning processes, as it is known for its role in complex thinking tasks. Accordingly, the scientists showed that inactivation of the prefrontal cortex impaired the mice’s performance in the maze.
“If three learning phases follow each other very quickly, we intuitively expected the same neurons to be activated,” Pieter Goltstein says. “After all, it is the same experiment with the same information. However, after a long break, it would be conceivable that the brain interprets the following learning phase as a new event and processes it with different neurons.” However, the researchers found exactly the opposite when they compared the neuronal activity during different learning phases. After short pauses, the activation pattern in the brain fluctuated more than compared to long pauses: In fast successive learning phases, the mice activated mostly different neurons. When taking longer breaks, the same neurons active during the first learning phase were used again later.
Memory benefits from longer breaks
Reactivating the same neurons could allow the brain to strengthen the connections between these cells in each learning phase – there is no need to start from scratch and establish the contacts first. “That’s why we believe that memory benefits from longer breaks,” says Pieter Goltstein.
Thus, after more than a century, the study provides the first insights into the neuronal processes that explain the positive effect of learning breaks. With spaced learning, we may reach our goal more slowly, but we benefit from our knowledge for much longer. Hopefully, we won’t have forgotten this by the time we take our next exam!
A team of scientists has identified the existence of a back-up plan for memory storage, which comes into play when the molecular mechanism of primary long-term memory storage fails.
Previous work had shown that mice engineered without an enzyme crucial to long-term memory storage could still form such memories, creating a controversy that a team of scientists has now resolved with the new research, which appears in the journal eLife.
The research focused on an enzyme made in nerve cells—PKMzeta. In a series of experiments, they confirmed that while the enzyme is crucial to long-term memory in normal mice, the mice engineered without PKMzeta still form long-term memories because they deploy an alternative, previously silent memory-storage method.
“Mice missing the PKMzeta enzyme essential for long-term memory are able to recruit a back-up mechanism for long-term memory storage,” explains André Fenton, a professor in NYU’s Center for Neural Science and one of the paper’s co-authors. “The question now is: how does PKMzeta function and what is the mechanism of its interaction with the PKCiota/lambda backup mechanisms?”
Previous research has found PKMzeta plays an important role in long-term memory storage, which scientists believe depends on the persistent strengthening of the connections between nerve cells. Specifically, the enzyme is made during the strengthening of these connections, and it remains in place so long as the links remain strong.
Notably, studies examining the role of PKMzeta’s in memory found that when the enzyme’s function was weakened in rodents,after they formed long-term memory, the animals could no longer remember diverse types of memories depending on diverse parts of the brain, suggesting that PKMzeta is a general memory storage mechanism.
But, recently, the importance of PKMzeta was questioned by experiments on genetically engineered “knockout” mice in which the gene that makes PKMzeta was deleted. Without PKMzeta, the knockout mice could still strengthen connections between nerve cells and still learn and remember.
While some took these results as evidence that PKMzeta’s role had previously been overstated, such studies did not consider the possibility of a “back-up” mechanism for memory that takes over when PKMzeta is removed. So the question remained: Is PKMzeta unimportant for memory or, in its absence, is a back-up mechanism deployed?
To address this matter, Panayiotis Tsokas, a research professor in Todd Sacktor’s lab at SUNY Downstate Medical Center, Fenton, and their colleagues tested both the “PKMzeta is unimportant” and “PKMzeta is compensated” hypotheses. To do so, they used a piece of modified DNA as a drug to block the formation of PKMzeta. If another molecule or molecules act as a back-up mechanism for PKMzeta, the scientists reasoned, the new drug would block the formation of memory in normal mice, but would have no effect on memory in the knockout mice that cannot make PKMzeta — the drug would have nothing to work on.
The results supported the PKMzeta is compensated hypothesis—the formation of memories normal mice was disrupted while that for the knockout mice was not, confirming the importance of PKMzeta, but also pointing to the presence of a back-up mechanism, which they identified involves PKCiota/lambda, the most closely related molecule to PKMzeta.
Desapareciste y las únicas pruebas de que alguna vez estuviste aquí conmigo ahora solo están en mis memorias.
Viajes al más allá
the year behind us now
has left a blistering hole in my heart
where my passion used to be-
each recollection of
events slowly numbs my senses
much like the start of this late winter-
but then comes you
draped in your black silk that
sways almost as elegantly as your
body-
you drag me from that driftless pub
towards a museum
where even the ruby paint and gold leaf trimmed elites
seem dull compared
to your celestial hair
red as Mars…
Memory process and strategies
Psychology divides the learning and memory creation process into three important stages
Encoding - initial learning of information
Storage - retaining of information in long-term memory
Retrieval - access and use of encoded and stored information
Strategies for different stages of the memory process
Encoding - initial exposure to stimulus
▫️ Elaborative encoding
▪️ A mnemonic that relates to-be-remembered information to previously existing memories and knowledge
▪️ If you are unable to answer “How?” or “Why?” then that could be a potential gap in your knowledge
▫️ Semantic encoding
▪️ The process of giving meaning to a piece of information employing techniques such as chunking, mnemonics, and memory palaces
▪️ The meaning of something (a word, phrase, picture, event, whatever) is encoded as opposed to the sound or vision of it
▪️ Semantic encoding results in better long-term retention of information when compared with strategies such as rote memorization
▫️ Dual coding
▪️ This is the idea of using different types of stimuli to help learners encode information in their brains more effectively. For example, visual and verbal
Storage- maintaining information on long-term memory
▫️ Chunking
▫️ Mnemonics
▫️ Sleeping
Retrieval - access and utilization of information that has been encoded and stored
▫️ Spaced retrieval
▫️ Interlearning
▫️ Testing effect
focused thinking vs diffuse thinking
focused thinking
▫️ targeted, concentrated and narrow thinking
▫️ need for a specific tasks
▫️ essential for acquiring knowledge and understanding
▫️ active
The strength of focused thinking lies in its ability to analyze and solve problems in a sequential manner
diffuse thinking
▪️ general, broad and conceptual thinking
▪️ creates connections and links
▪️ essential for consolidation of memory
▪️ passive
Rather than being focused on a defined path, diffuse thinking allows your subconscious to make unexpected connections between disparate ideas
The trick is not to choose between the two approaches, but rather to cycle between focused and diffuse thinking for the most significant impact
Want to learn an unfamiliar and challenging concept ❓ Study it with focused thinking, then let your brain shift into diffuse thinking. The combination will allow your conscious brain to investigate the idea while your subconscious mind forms new links and connections to embed it into your memory and thinking
I recently finished reading this Hunter S. Thompson “oral history” I found at the thrift store a few years ago, GONZO, and the whole time I was like, how was this man not an Aries? The arrogance! The pure unadulterated ambition! The total and complete selfishness! The idiotic stubbornness! I mean, his “character” was relatable in an eerie kind of “evil twin” way. I kept thinking to myself, dude sounds exactly like if me (Aries) and my abusive ex (extremely Pisces) were the same person. The paranoia, the watery moods, the fucking apocalyptic meltdowns, the dragging of everyone around you down into yr own mostly self-created pit of despair and rage. The unrelenting desire to drive drunk directly into a brick wall, basically. It all felt uncannily familiar! So finally, just for laughs, I looked up his natal chart… and apparently, that motherfucker was an Aries rising. ONE DEGREE away from Pisces! :v I keep saying I’m a skeptic who is just here for the memes but this is ridiculous lmao
Another thing I found personally disorienting is that the book didn’t include anything about Hunter S. Thompson and “STET.” Stet is a Latin word meaning “let it stand,” and it’s used in proofreading to say that a word or phrase that was crossed out should stay the same. I got it tattooed on my knuckles on my 30th birthday for reasons unrelated to HST, however, it has always been my understanding that I first learned that word ages ago, when I’d heard or read somewhere that he used to send his edited manuscripts back to Jann Wenner or whoever, all marked up with STETs as he constantly fought with editors over proofreading decisions. In my memory I feel like this is something I learned? absorbed? imagined?? back when I was like 18 or 20ish, and it’s always been this minor detail that took on mythic proportions – I mean, the story definitely appeals to my own distaste for editing ~muh work~ – but I guess it’s just part of my own personal apocrypha, because I cannot even find a damn thing about it online. Could it have been some other tortured white male author? HMM. Love 2 b my own unreliable narrator I guess!
“The body is a haunted terrain—a living record of personal, familial, social, and epigenetic memory. To look at my father’s body now—the way he shuffles when he walks, the atrophy in his once-nimble fingers, the nerve pain in his feet, the cloudiness in his eyes as he loses his sight—it too is a record of a forgotten life, and of the systems that failed it. I carry the memory of him in his splendor and his decline. And what I carry of him is also connected to the land, its seam connecting memory, legacy into the future. Memory itself is a kind of map, linked to textures, smells, songs, places, the act of remembering in and of itself a kind of haunting. Music is one of the few portals I have into my fragmented memory, and writing the only way I know to recover my people from the nothing of forgetting, to resist the erasure of the border and its constant overwriting of history, to salvage what is disappearing.”—Vanessa Angélica Villarreal, from “La Cancion de la Nena,” Oxford American (Summer 2021)
The water has been running in the shower for a little bit. There is just a little steam forming in the bathroom. I step into the shower and the first sprays of water land on my lower legs. It is just the right temperature - hot enough to make my skin come alive, but not hot enough to cause any lasting discomfort. I close my eyes and slowly walk further into the steady flow of water. The warmth spreads up my thighs and I pause just for a moment before moving a little further to have the water pass over my cock and balls. I feel the heat. Then I step further letting the water cascade over my chest. I take my hands and slide them down my body. They pass easily over my wet skin and are drawn down between my legs. They cannot help but linger.
My fingers gently squeeze the tip of my cock. I feel that light tingle beckoning me. My hand slides down and fingers close around my balls, rolling them softly in my hand. Both hands turn to a light touch and slowly run up and my thighs, each alternating running up and down my cock. I feel the warm water falling down my body. The tease won’t be a slow one for me though as my hand closes finger by finger around my cock. Slowly and lightly I rub once back and forth. For me, it’s always my left hand … which is odd as I’m right handed. Touching myself with my right hand can be a slow and deliberate affair. But when it is my left, the rhythm starts almost immediately when I feel my hand close around myself.
I feel myself grow … not too quickly … but steadily. My right hand lightly runs over my scrotum. I love the soft touch there. In fact, I decide to give myself a treat and reach out for the handheld wand. Turning it on brings an additional source of water and the small, skinny streams of water feel amazing when I run them between my legs. My strokes continue as the water lightly teases my balls.
It’s at this point that my eyes close and my mind wanders. I tend to drift between some favorite memories and desired fantasies. It only takes one or two to bring me to full arousal. My hand moving lightly over my now straight and firm cock. The soft water streams tickling my balls. My teeth bite down on my lip.
My thoughts drift to those memories of things I should not have done, but did anyway. The risk always turns me on. I turn off the water to the handheld wand and place it back on the holder. I then turn to face away from the shower heard. The water from the showerhead streams down my back. I lean down and spit down on my cock … water doesn’t provide the same lubrication. I focus on the sensations. I go beyond the friction of my hand on my cock and to that tingle - that little thread of feeling that runs all the way from the tip back deep inside my body. That’s what I’m seeking. That’s what I want to play with … that little electric tingling thread. I pull it forward and let it fall back. My mind now drifts to some of those favorite unfulfilled fantasies … those scenes I’ve written in mind … the ones that take my breath away. That I hope may one day be reality and then a memory - no longer a fantasy. I feel those first internal muscle contractions. They are shallow and empty now … but soon they’ll grow much stronger. I add a little more spit. My rhythm quickens. I lean forward with my right hand and steady myself against the wall. My mind starts randomly pulling memories and fantasies together … actions … scenes … stories … conversations … photographs … audios … videos … Sometimes the memories are far from my past. Sometimes very recent. Often both. I do not lack for inspiration when I let my mind turn those forbidden corners to explore those places most private and most erotic.
It doesn’t take too long to find that exact point where I can almost feel the cum begin to move - but I slow it down to keep it right there on the edge. It’s that moment that if I weren’t in the shower, I would see the pre-cum glistening on the tip. It feels so good to rub that around the head. The longer I can keep that edge, the more I will ejaculate. Sometimes I go a little too far and have to clamp down to hold the orgasm back. This is the moment when I am hardest - so taut and ready to release. Letting it fall back. Pulling it forward. Here I need to be careful with my mind. The right thought in my mind will easily pull me past the point of no return. I think this has gradually changed over the course of my life - orgasms are so thought-dependent and so intellectual. I can touch myself for extended periods and not get that close. But if I let my mind wander to those places …
So there I stand, braced against the wall. Water falling around me. I play that tug of war with that thread … feeling that connection back up inside me … carefully letting my mind get further and further to the edge. But soon, the moment comes when I know it is time to give it over. To lose control and let my body do what it wants without me guiding it. That’s when my mind goes furthest afield - those riskiest desires and fantasies - those experiences I’ve had that turn me on the most. And then I push it just to the edge and then over. It’s about 3-4 seconds of this building fullness throughout my cock and then that tingling thread goes fully taut. I’m over the edge. It can’t be stopped now. I know the cum has begun to move. I can feel that first muscle contraction and then give over to it. The first spasm releases just a bit of that thick, white fluid. I watch it fall to my feet. But the second one is almost always the largest. Again and again, those spasms continue. That stream of liquid pushing out from deep inside is broken up over and over with those muscle contractions pushing it out. Often then fifth or sixth contraction will also be larger. Gradually the remaining cum slides out and down my hand. My strokes slow. I squeeze the head which pushes out a little more. It’s at this point that I remember the shower - I’ve been off in some other place through the entire experience. I turn and let the water run down my front. My cock is slowly relaxing. I reach back down and squeeze along the underside, pushing out as much cum as I can that remains, before rinsing my hand and finishing the shower.
I can still feel the residual effects of that tingling thread for twenty or thirty minutes afterwards, and the little residual cum that makes its way out is a reminder of my pleasure and release. That feeling of being spent. The stress relieved in those few moments when I gave over control. As I dress for the day, my mind turns reluctantly from the few moments of enjoyment … but I know tomorrow will come and with it the chance to spend a little more time in that fantasyland, that place where I can escape my reality and be me.