Posts tagged memory

“Watch This Disturbing Cyberpunk Movie About Turning Memories into Drugs”

…about a guy who invents a machine that turns him into a lowlife memory dealer.

It’s got a gritty, realistic feel and a weird premise that sometimes doesn’t quite work — but then, when it does, it’s a smart exploration of how memories shape who we are.

What if you could ingest other people’s memories? Would you change? How many things would you forget in the process of making room for these new recollections? Aren’t our own memories of the past a kind of drug already? [via]

I got 5 on it. 

“MIT researchers turn on a memory” Researchers chose to test a simple kind of memory — a fear memory. In one experiment, mice were put in a chamber, allowed to explore, and given a foot shock. The next time the mice were put in the same dangerous chamber, they remembered the unpleasant electric shock and froze, taking on a defensive stance. Researchers had, however, inserted a gene that codes for a light-sensitive protein into the cells involved in making a memory. They then tested what happened when they turned on a light to activate those cells, without putting the mice in the same chamber. They saw the freezing behavior, as if the mice were reliving the memory. “This is the most dramatic way to show that high cognitive phenomenon, like memory recall, can be generated, can be artificially generated by poking cells in the brain,” Tonegawa said in an interview. He said there were about 20,000 neurons, or brain cells, involved in this particular kind of memory.  [via] I’ve seen a couple of these optogenetic experiments. It’s pretty fascinating to be able to manipulate the neural response in vivo.  

“MIT researchers turn on a memory”

Researchers chose to test a simple kind of memory — a fear memory. In one experiment, mice were put in a chamber, allowed to explore, and given a foot shock. The next time the mice were put in the same dangerous chamber, they remembered the unpleasant electric shock and froze, taking on a defensive stance. Researchers had, however, inserted a gene that codes for a light-sensitive protein into the cells involved in making a memory. They then tested what happened when they turned on a light to activate those cells, without putting the mice in the same chamber. They saw the freezing behavior, as if the mice were reliving the memory.

“This is the most dramatic way to show that high cognitive phenomenon, like memory recall, can be generated, can be artificially generated by poking cells in the brain,” Tonegawa said in an interview.

He said there were about 20,000 neurons, or brain cells, involved in this particular kind of memory.  [via]

I’ve seen a couple of these optogenetic experiments. It’s pretty fascinating to be able to manipulate the neural response in vivo.  

Given the complexity of the human brain, there are likely to be numerous other structural variations which could also be associated with individual differences in cognitive function. If that is the case, there may be no such thing as a ‘typical’ human brain, and the term ‘neurotypical’ is meaningless.
Mo Costandi talking about new research on “the presence or absence of the paracingulate sulcus, in the prefrontal cortex” in a new post: Memory errors are all in the groove: A new study links individual differences in cognitive function to structural variations in the brain.
Neurophysicists to everyone: “There is an optimal brain frequency” We may be familiar with the concept of electrical/chemical signals relating to neural communication. So, now imagine of every synapse branching out from every neuron - like an antenna, is tuned to a different frequency signal with a specific optimal point and this optimum frequency point depends on the location of the synapse on a neuron. The farther away the synapse is from the neuron’s cell body, the higher the optimum frequency was found to be.  And it seems the more rhythmicly synced the frequencies were - the stronger the connection for memory and learning synapses.  The researchers found that not only does each synapse have a preferred frequency for achieving optimal learning, but for the best effect, the frequency needs to be perfectly rhythmic — timed at exact intervals. Even at the optimal frequency, if the rhythm was thrown off, synaptic learning was substantially diminished. Their research also showed that once a synapse learns, its optimal frequency changes. In other words, if the optimal frequency for a naïve synapse — one that has not learned anything yet — was, say, 30 spikes per second, after learning, that very same synapse would learn optimally at a lower frequency, say 24 spikes per second. Thus, learning itself changes the optimal frequency for a synapse. As well as possibly strengthening and enhancing learning and memory, learning-induced re-tuning and de-tuning could be have “important implications for treating disorders related to forgetting, such as PTSD disorder”.  via Life is just a frequency… The image shows a neuron with a tree trunk-like dendrite. Each triangular shape touching the dendrite represents a synapse, where inputs from other neurons, called spikes, arrive (the squiggly shapes). Synapses that are further away on the dendritic tree from the cell body require a higher spike frequency (spikes that come closer together in time) and spikes that arrive with perfect timing to generate maximal learning. VIA image

Neurophysicists to everyone: “There is an optimal brain frequency”

We may be familiar with the concept of electrical/chemical signals relating to neural communication. So, now imagine of every synapse branching out from every neuron - like an antenna, is tuned to a different frequency signal with a specific optimal point and this optimum frequency point depends on the location of the synapse on a neuron. The farther away the synapse is from the neuron’s cell body, the higher the optimum frequency was found to be.  And it seems the more rhythmicly synced the frequencies were - the stronger the connection for memory and learning synapses.

 The researchers found that not only does each synapse have a preferred frequency for achieving optimal learning, but for the best effect, the frequency needs to be perfectly rhythmic — timed at exact intervals. Even at the optimal frequency, if the rhythm was thrown off, synaptic learning was substantially diminished.

Their research also showed that once a synapse learns, its optimal frequency changes. In other words, if the optimal frequency for a naïve synapse — one that has not learned anything yet — was, say, 30 spikes per second, after learning, that very same synapse would learn optimally at a lower frequency, say 24 spikes per second. Thus, learning itself changes the optimal frequency for a synapse.

As well as possibly strengthening and enhancing learning and memory, learning-induced re-tuning and de-tuning could be have “important implications for treating disorders related to forgetting, such as PTSD disorder”.  via

Life is just a frequency…

The image shows a neuron with a tree trunk-like dendrite. Each triangular shape touching the dendrite represents a synapse, where inputs from other neurons, called spikes, arrive (the squiggly shapes). Synapses that are further away on the dendritic tree from the cell body require a higher spike frequency (spikes that come closer together in time) and spikes that arrive with perfect timing to generate maximal learning. VIA

image

Electrically Stimulating News for Your Brain: Keeping a little pace with my translational neuroscience research theme here are two blurbs that came out.  “Electrical stimulation of brain boosts birth of new cells” Stimulating a specific region of the brain leads to the production of new brain cells that enhance memory, according to an animal study in the September 21 issue of The Journal of Neuroscience. The findings show how deep brain stimulation (DBS) — a clinical intervention that delivers electrical pulses to targeted areas of the brain — may work to improve cognition.   Throughout life, new cells are born in parts of the hippocampus, the brain’s learning and memory center. In the new study, Frankland and his colleagues found that one hour of electrical stimulation to the entorhinal cortex — a region that directly communicates with the hippocampus — in adult mice led to a two-fold increase in new cells in the hippocampus. Although the burst of new cells lasted for only about one week, the cells produced during this time window developed normally and made connections with other nearby brain cells. via Why only a week? What happened to those connections? And what’s that image mean? Look at the little dotted circle: Mice who received deep brain stimulation (DBS) to a region in the brain called the entorhinal cortex showed an enhanced ability to learn how to navigate to a designated target. This image shows DBS mice (S) spent a greater amount of time (indicated in red) swimming near a submerged landing (dotted circle) compared with non-stimulated mice (NS). via And moving from this idea from mice to men, what can you do with all those new cells? Well, in this study using both fMRI and TMS, giving both spacial and temporal data comparing stroke patients and healthy volunteers,  researchers  showed: “Electrical Stimulation to the Brain Can Improve Learning” Researchers from the University of Oxford conducted a study showing that applying a small current of electricity to a specific part of the brain can increase its activity, therefore making learning quicker and easier. (…) an unexpected result was also discovered. When this brain stimulation was applied to healthy adults, using the trans-cranial current simulation device, their speed of learning also increased.  They found that depending on the direction of the current passed through the brain, rate of learning decreased or increased in that part of the brain. via Fascinating, I’m sure we will be hearing lots more about this. One of the big neurogenesis questions we had when I worked in this area was kinda a chicken or the egg question: do new cells increase memory/learning efficacy or does learning and using your memory encourage neurogenesis? We did get somewhere with frequencies & neuron death…but that’s a whoooole other enchilada.

Electrically Stimulating News for Your Brain:

Keeping a little pace with my translational neuroscience research theme here are two blurbs that came out. 

“Electrical stimulation of brain boosts birth of new cells”

Stimulating a specific region of the brain leads to the production of new brain cells that enhance memory, according to an animal study in the September 21 issue of The Journal of Neuroscience. The findings show how deep brain stimulation (DBS) — a clinical intervention that delivers electrical pulses to targeted areas of the brain — may work to improve cognition. 
 Throughout life, new cells are born in parts of the hippocampus, the brain’s learning and memory center. In the new study, Frankland and his colleagues found that one hour of electrical stimulation to the entorhinal cortex — a region that directly communicates with the hippocampus — in adult mice led to a two-fold increase in new cells in the hippocampus. Although the burst of new cells lasted for only about one week, the cells produced during this time window developed normally and made connections with other nearby brain cells. via

Why only a week? What happened to those connections? And what’s that image mean? Look at the little dotted circle:

Mice who received deep brain stimulation (DBS) to a region in the brain called the entorhinal cortex showed an enhanced ability to learn how to navigate to a designated target. This image shows DBS mice (S) spent a greater amount of time (indicated in red) swimming near a submerged landing (dotted circle) compared with non-stimulated mice (NS). via

And moving from this idea from mice to men, what can you do with all those new cells? Well, in this study using both fMRI and TMS, giving both spacial and temporal data comparing stroke patients and healthy volunteers,  researchers  showed: “Electrical Stimulation to the Brain Can Improve Learning”

Researchers from the University of Oxford conducted a study showing that applying a small current of electricity to a specific part of the brain can increase its activity, therefore making learning quicker and easier.

(…) an unexpected result was also discovered.

When this brain stimulation was applied to healthy adults, using the trans-cranial current simulation device, their speed of learning also increased.  They found that depending on the direction of the current passed through the brain, rate of learning decreased or increased in that part of the brain. via

Fascinating, I’m sure we will be hearing lots more about this. One of the big neurogenesis questions we had when I worked in this area was kinda a chicken or the egg question: do new cells increase memory/learning efficacy or does learning and using your memory encourage neurogenesis? We did get somewhere with frequencies & neuron death…but that’s a whoooole other enchilada.

Police Lineups Start to Face Fact: Eyes Can Lie

Good article here addressing the flawed and unreliable practice of eyewitness identification procedures and what changes are being done to correct this after decades worth of research. 

The idea that human memory is frail and suggestible has gradually gained acceptance among leaders in law enforcement, buttressed by more than 2,000 scientific studies demonstrating problems with witness accounts and the DNA exonerations of at least 190 people whose wrongful convictions involved mistaken identifications. About 75,000 witness identifications take place each year, and studies suggest that about a third are incorrect.

 Although NJ’s Supreme court is taking this bull by the horn and implementing the changes, some jurisdictions are lagging. For instance, this doesn’t bother Sgt. Cassidee Carlson, a Police Department spokeswoman, in Aurora, Colorado who seems to have a caviler approach saying “…the department had no written policy and did not follow the National Justice Institute guidelines because there was no state mandate to do so.”   Pro-activeness and preventive measures? Not here!

For now, everybody’s satisfied,” Sergeant Carlson said. “This is the system we have in place, and it works with our court system.

You’d think the worst thing that could happen is the trouble of learning an effective procedure that protects innocent people as well as the integrity of the police.

In NY, 15 people have been exonerated for eyewitness misidentification.

Your memory isn't shot, you may just happy.

This research is the first to show that positive mood can negatively impact working memory storage capacity. via  from @TheBrainScience 

In around 2001-05, it was found that mood affects memory: sad mood reduces false memories, happiness increases false memories in the encoding process:

Individuals in negative moods were significantly less likely to show false memory effects than those in positive moods or those whose mood was not manipulated. The results replicated the false memory finding of Experiment 1 and provide evidence that moods influence the accessibility of lures at encoding, rather than influencing monitoring at retrieval of whether lures were actually presented.  via

Oh wait, you were wearing that red shirt.

MIT neuroscientists explain ‘Proustian effect’ of small details attached to big memories

Previous research has focused on the role of synapses—the connections through which neurons communicate. An individual synapse is thought to be the minimum unit necessary to establish a memory engram. 

 The MIT researchers found that a memory of a seemingly irrelevant detail — the kind of detail that would normally be relegated to a short-term memory — may accompany a long-term memory if two synapses on a single dendritic arbor are stimulated within an hour and a half of each other.

It’s about the timing and strength of the signals that determine a short v. long term memory.

This occurs because the weakly stimulated synapse can steal or hitchhike on a set of proteins synthesised at or near the strongly stimulated synapse. These proteins are necessary for the enlargement of a dendritic spine that allows the establishment of a long-term memory.

“Not all irrelevant information is recalled, because some of it did not stimulate the synapses of the dendritic branch that happens to contain the strongly stimulated synapse,” Israely said.

Neuroskeptic, why ya buggin? Finally, a study I don’t need to backtree to know all about… the RUN DMC study.       Oh, wait. Verbal memory, SVD and hippocampal atrophy??  Nevermind. He’s talking about the RUN DMC study that stands for “Radboud  University  Nijmegen Diffusion tensor and Magnetic resonance imaging Cohort study” in his alluring post Neural Correlates of 80s Hip Hop,  which is not only my jam- but may be the largest neuroimaging study to date where: the theory (…) is that in elderly people, white matter often shows degeneration. This is thought to be caused by vascular disease - problems with the blood flow to the brain, such as cerebral small-vessel disease which means, essentially, a series of mild strokes, which often go unnoticed at the time, but they build up to cause brain damage, specifically white matter disruption. You kids are too young to know the reference, but your getting older by the second (memory problems, tick/tock). Click thru before you forget, and give it a read to learn why this matters in terms of early detection, among other reasons. Neuroskeptic never disappoints. (bonus: photoshop skills!)

Neuroskeptic, why ya buggin?

Finally, a study I don’t need to backtree to know all about… the RUN DMC study.      

Oh, wait. Verbal memory, SVD and hippocampal atrophy??  Nevermind.

He’s talking about the RUN DMC study that stands for “Radboud  University  Nijmegen Diffusion tensor and Magnetic resonance imaging Cohort study” in his alluring post Neural Correlates of 80s Hip Hop,  which is not only my jam- but may be the largest neuroimaging study to date where:

the theory (…) is that in elderly people, white matter often shows degeneration. This is thought to be caused by vascular disease - problems with the blood flow to the brain, such as cerebral small-vessel disease which means, essentially, a series of mild strokes, which often go unnoticed at the time, but they build up to cause brain damage, specifically white matter disruption.

You kids are too young to know the reference, but your getting older by the second (memory problems, tick/tock). Click thru before you forget, and give it a read to learn why this matters in terms of early detection, among other reasons. Neuroskeptic never disappoints. (bonus: photoshop skills!)

The Brain That Changed Everything

You can spend a half century testing somebody, examining, poking, prodding, feeding — Henry will happily eat at least two full dinners in a row if you give him a minute between removing the first tray and replacing it with the second — and you can come up with all sorts of theories to explain your findings. You can even throw a person in an MRI machine, study the flickering images on your computer screen. But the brain is the ultimate black box. Eventually, to grasp the first cut, you’ll have to make another.

Love this article - all about the journey of Henry Molaison, from epilepsy treatment to being the most famous neuroscience patient in history, written by the grandson of H.M.’s doctor.

 

thegradlife: Ever since a certain tumblr clued me in, I’ve been writing all of my multivariate notes in red pen! Is it working for you?  I think I’m a believer…but I did notice a drop off when I used yellow legal pad instead of neutral color paper.

thegradlife:

Ever since a certain tumblr clued me in, I’ve been writing all of my multivariate notes in red pen!

Is it working for you?  I think I’m a believer…but I did notice a drop off when I used yellow legal pad instead of neutral color paper.

Do we really do experience time more slowly when our life is in danger?

The piece riffs on a 2007 study called ‘Does Time Really Slow Down during a Frightening Event?’ led by neuroscientist David Eagleman who discusses the project on the show.

The experimenters wanted a way to find a way to test whether we suddenly start experiencing time in greater detail when in mortal danger, or whether it just seems that way when we look back on it.

The findings of the research suggest that “time-slowing is a function of recollection, not perception: a richer encoding of memory may cause a salient event to appear, retrospectively, as though it lasted longer.”

Listen  - NPR on fear and slow motion perception or read the study.

(via)

Mood and the False Memory Effect

With Sadness Comes Accuracy; With Happiness, False Memory

“In two experiments, we found that affect can influence the encoding processes believed to lead to the production of false memories. In particular, negative affective cues reduced the false memory effect.”

Also suggesting:

…that positive affect can be expected to benefit performance on tasks requiring relational processing, but that negative affect may benefit performance on tasks requiring referential processing. In the present task, the referential processing of negative moods led to accuracy, whereas the relational processing of positive moods led to false memories.

I sat down with the author of this study yesterday. This is one of the first articles he did laying the ground work for his more recent research on how people who report being sad have better spacial recall and those who report being happy have better verbal recall.