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We don’t lose our keys (or other things) as much as we think
Can’t find your keys? Misplaced your glasses? No clue where you parked your car?
We all lose things from time to time. And we’ve all heard the standard-issue advice: Picture when you had the object last. Despite this common experience,
“It is well known that we have massive recognition memory for objects,” says study coauthor Jeremy Wolfe, PhD, a professor of ophthalmology and radiology at Harvard Medical School, Boston. In other words, we’re good at recognizing objects we’ve seen before. “For example, after viewing 100 objects for 2-3 seconds each, observers can discriminate those 100 old images from 100 new ones with well over 80% accuracy.”
But remembering what your keys look like won’t necessarily help you find them. “We often want to know when and where we saw [an object],” Dr. Wolfe says. “So our goal was to measure these spatial and temporal memories.”
In a series of experiments, reported in Current Biology, Wolfe and colleagues asked people in the study to remember objects placed on a grid. They viewed 300 objects (pictures of things like a vase, a wedding dress, camo pants, a wet suit) and were asked to recall each one and where it had been located on the grid.
About a third of the people remembered 100 or more locations, by choosing either the correct square on the grid or one directly next to it. Another third remembered between 50 and 100, and the rest remembered less than 50.
Results would likely be even better in the real world “because no one gives up and decides ‘I can’t remember where anything is. I will just guess in this silly experiment,’ ” Dr. Wolfe says.
Later, they were shown items one at a time and asked to click on a time line to indicate when they had seen them. Between 60% and 80% of the time, they identified when they had seen an object within 10% of the correct time. That’s a lot better than the 40% they would have achieved by guessing.
The findings build on previous research and expand our understanding of memory, Dr. Wolfe says. “We knew that people could remember where some things were located. However, no one had tried to quantify that memory,” he says.
But wait: If we’re so good at remembering the where and when, why do we struggle to locate lost objects so much? Chances are, we don’t. We just feel that way because we tend to focus on the fails and overlook the many wins.
“This [study] is showing us something about how we come to know where hundreds of things are in our world,” Dr. Wolfe says. “We tend to notice when this fails – ‘where are my keys?’ – but on a normal day, you are successfully tapping a massive memory on a regular basis.”
Next, the researchers plan to investigate whether spatial and temporal memories are correlated – if you’re good at one, are you good at the other? So far, “that correlation looks rather weak,” Dr. Wolfe says.
A version of this article first appeared on WebMD.com.
Can’t find your keys? Misplaced your glasses? No clue where you parked your car?
We all lose things from time to time. And we’ve all heard the standard-issue advice: Picture when you had the object last. Despite this common experience,
“It is well known that we have massive recognition memory for objects,” says study coauthor Jeremy Wolfe, PhD, a professor of ophthalmology and radiology at Harvard Medical School, Boston. In other words, we’re good at recognizing objects we’ve seen before. “For example, after viewing 100 objects for 2-3 seconds each, observers can discriminate those 100 old images from 100 new ones with well over 80% accuracy.”
But remembering what your keys look like won’t necessarily help you find them. “We often want to know when and where we saw [an object],” Dr. Wolfe says. “So our goal was to measure these spatial and temporal memories.”
In a series of experiments, reported in Current Biology, Wolfe and colleagues asked people in the study to remember objects placed on a grid. They viewed 300 objects (pictures of things like a vase, a wedding dress, camo pants, a wet suit) and were asked to recall each one and where it had been located on the grid.
About a third of the people remembered 100 or more locations, by choosing either the correct square on the grid or one directly next to it. Another third remembered between 50 and 100, and the rest remembered less than 50.
Results would likely be even better in the real world “because no one gives up and decides ‘I can’t remember where anything is. I will just guess in this silly experiment,’ ” Dr. Wolfe says.
Later, they were shown items one at a time and asked to click on a time line to indicate when they had seen them. Between 60% and 80% of the time, they identified when they had seen an object within 10% of the correct time. That’s a lot better than the 40% they would have achieved by guessing.
The findings build on previous research and expand our understanding of memory, Dr. Wolfe says. “We knew that people could remember where some things were located. However, no one had tried to quantify that memory,” he says.
But wait: If we’re so good at remembering the where and when, why do we struggle to locate lost objects so much? Chances are, we don’t. We just feel that way because we tend to focus on the fails and overlook the many wins.
“This [study] is showing us something about how we come to know where hundreds of things are in our world,” Dr. Wolfe says. “We tend to notice when this fails – ‘where are my keys?’ – but on a normal day, you are successfully tapping a massive memory on a regular basis.”
Next, the researchers plan to investigate whether spatial and temporal memories are correlated – if you’re good at one, are you good at the other? So far, “that correlation looks rather weak,” Dr. Wolfe says.
A version of this article first appeared on WebMD.com.
Can’t find your keys? Misplaced your glasses? No clue where you parked your car?
We all lose things from time to time. And we’ve all heard the standard-issue advice: Picture when you had the object last. Despite this common experience,
“It is well known that we have massive recognition memory for objects,” says study coauthor Jeremy Wolfe, PhD, a professor of ophthalmology and radiology at Harvard Medical School, Boston. In other words, we’re good at recognizing objects we’ve seen before. “For example, after viewing 100 objects for 2-3 seconds each, observers can discriminate those 100 old images from 100 new ones with well over 80% accuracy.”
But remembering what your keys look like won’t necessarily help you find them. “We often want to know when and where we saw [an object],” Dr. Wolfe says. “So our goal was to measure these spatial and temporal memories.”
In a series of experiments, reported in Current Biology, Wolfe and colleagues asked people in the study to remember objects placed on a grid. They viewed 300 objects (pictures of things like a vase, a wedding dress, camo pants, a wet suit) and were asked to recall each one and where it had been located on the grid.
About a third of the people remembered 100 or more locations, by choosing either the correct square on the grid or one directly next to it. Another third remembered between 50 and 100, and the rest remembered less than 50.
Results would likely be even better in the real world “because no one gives up and decides ‘I can’t remember where anything is. I will just guess in this silly experiment,’ ” Dr. Wolfe says.
Later, they were shown items one at a time and asked to click on a time line to indicate when they had seen them. Between 60% and 80% of the time, they identified when they had seen an object within 10% of the correct time. That’s a lot better than the 40% they would have achieved by guessing.
The findings build on previous research and expand our understanding of memory, Dr. Wolfe says. “We knew that people could remember where some things were located. However, no one had tried to quantify that memory,” he says.
But wait: If we’re so good at remembering the where and when, why do we struggle to locate lost objects so much? Chances are, we don’t. We just feel that way because we tend to focus on the fails and overlook the many wins.
“This [study] is showing us something about how we come to know where hundreds of things are in our world,” Dr. Wolfe says. “We tend to notice when this fails – ‘where are my keys?’ – but on a normal day, you are successfully tapping a massive memory on a regular basis.”
Next, the researchers plan to investigate whether spatial and temporal memories are correlated – if you’re good at one, are you good at the other? So far, “that correlation looks rather weak,” Dr. Wolfe says.
A version of this article first appeared on WebMD.com.
FROM CURRENT BIOLOGY
Waking up at night could be your brain boosting your memory
We tend to think a good night’s sleep should be uninterrupted, but surprising new research from the University of Copenhagen suggests just the opposite:
The study, done on mice, found that the stress transmitter noradrenaline wakes up the brain many times a night. These “microarousals” were linked to memory consolidation, meaning they help you remember the previous day’s events. In fact, the more “awake” you are during a microarousal, the better the memory boost, suggests the research, which was published in Nature Neuroscience.
“Every time I wake up in the middle of the night now, I think – ah, nice, I probably just had great memory-boosting sleep,” said study author Celia Kjaerby, PhD, an assistant professor at the university’s Center for Translational Neuromedicine.
The findings add insight to what happens in the brain during sleep and may help pave the way for new treatments for those who have sleep disorders.
Waves of noradrenaline
Previous research has suggested that noradrenaline – a hormone that increases during stress but also helps you stay focused – is inactive during sleep. So, the researchers were surprised to see high levels of it in the brains of the sleeping rodents.
“I still remember seeing the first traces showing the brain activity of the norepinephrine stress system during sleep. We could not believe our eyes,” Dr. Kjaerby said. “Everyone had thought the system would be quiet. And now we have found out that it completely controls the microarchitecture of sleep.”
Those noradrenaline levels rise and fall like waves every 30 seconds during non-REM (NREM) sleep. At each “peak” the brain is briefly awake, and at each “valley” it is asleep. Typically, these awakenings are so brief that the sleeping subject does not notice. But the higher the rise, the longer the awakening – and the more likely the sleeper may notice.
During the valleys, or when norepinephrine drops, so-called sleep spindles occur.
“These are short oscillatory bursts of brain activity linked to memory consolidation,” Dr. Kjaerby said. Occasionally there is a “deep valley,” lasting 3-5 minutes, leading to more sleep spindles. The mice with the most deep valleys also had the best memories, the researchers noted.
“We have shown that the amount of these super-boosts of sleep spindles, and not REM sleep, defines how well you remember the experiences you had prior to going to sleep,” said Dr. Kjaerby.
Deep valleys were followed by longer awakenings, the researchers observed. So, the longer the valley, the longer the awakening – and the better the memory boost. This means that, though restless sleep is not good, waking up briefly may be a natural part of memory-related sleep phases and may even mean you’ve slept well.
What happens in our brains when we sleep: Piecing it together
The findings fit with previous clinical data that shows we wake up roughly 100-plus times a night, mostly during NREM sleep stage 2 (the spindle-rich sleep stage), Dr. Kjaerby said.
Still, more research on these small awakenings is needed, Dr. Kjaerby said, noting that professor Maiken Nedergaard, MD, another author of this study, has found that the brain cleans up waste products through a rinsing fluid system.
“It remains a puzzle why the fluid system is so active when we sleep,” Dr. Kjaerby said. “We believe these short awakenings could potentially be the key to answering this question.”
A version of this article first appeared on WebMD.com.
We tend to think a good night’s sleep should be uninterrupted, but surprising new research from the University of Copenhagen suggests just the opposite:
The study, done on mice, found that the stress transmitter noradrenaline wakes up the brain many times a night. These “microarousals” were linked to memory consolidation, meaning they help you remember the previous day’s events. In fact, the more “awake” you are during a microarousal, the better the memory boost, suggests the research, which was published in Nature Neuroscience.
“Every time I wake up in the middle of the night now, I think – ah, nice, I probably just had great memory-boosting sleep,” said study author Celia Kjaerby, PhD, an assistant professor at the university’s Center for Translational Neuromedicine.
The findings add insight to what happens in the brain during sleep and may help pave the way for new treatments for those who have sleep disorders.
Waves of noradrenaline
Previous research has suggested that noradrenaline – a hormone that increases during stress but also helps you stay focused – is inactive during sleep. So, the researchers were surprised to see high levels of it in the brains of the sleeping rodents.
“I still remember seeing the first traces showing the brain activity of the norepinephrine stress system during sleep. We could not believe our eyes,” Dr. Kjaerby said. “Everyone had thought the system would be quiet. And now we have found out that it completely controls the microarchitecture of sleep.”
Those noradrenaline levels rise and fall like waves every 30 seconds during non-REM (NREM) sleep. At each “peak” the brain is briefly awake, and at each “valley” it is asleep. Typically, these awakenings are so brief that the sleeping subject does not notice. But the higher the rise, the longer the awakening – and the more likely the sleeper may notice.
During the valleys, or when norepinephrine drops, so-called sleep spindles occur.
“These are short oscillatory bursts of brain activity linked to memory consolidation,” Dr. Kjaerby said. Occasionally there is a “deep valley,” lasting 3-5 minutes, leading to more sleep spindles. The mice with the most deep valleys also had the best memories, the researchers noted.
“We have shown that the amount of these super-boosts of sleep spindles, and not REM sleep, defines how well you remember the experiences you had prior to going to sleep,” said Dr. Kjaerby.
Deep valleys were followed by longer awakenings, the researchers observed. So, the longer the valley, the longer the awakening – and the better the memory boost. This means that, though restless sleep is not good, waking up briefly may be a natural part of memory-related sleep phases and may even mean you’ve slept well.
What happens in our brains when we sleep: Piecing it together
The findings fit with previous clinical data that shows we wake up roughly 100-plus times a night, mostly during NREM sleep stage 2 (the spindle-rich sleep stage), Dr. Kjaerby said.
Still, more research on these small awakenings is needed, Dr. Kjaerby said, noting that professor Maiken Nedergaard, MD, another author of this study, has found that the brain cleans up waste products through a rinsing fluid system.
“It remains a puzzle why the fluid system is so active when we sleep,” Dr. Kjaerby said. “We believe these short awakenings could potentially be the key to answering this question.”
A version of this article first appeared on WebMD.com.
We tend to think a good night’s sleep should be uninterrupted, but surprising new research from the University of Copenhagen suggests just the opposite:
The study, done on mice, found that the stress transmitter noradrenaline wakes up the brain many times a night. These “microarousals” were linked to memory consolidation, meaning they help you remember the previous day’s events. In fact, the more “awake” you are during a microarousal, the better the memory boost, suggests the research, which was published in Nature Neuroscience.
“Every time I wake up in the middle of the night now, I think – ah, nice, I probably just had great memory-boosting sleep,” said study author Celia Kjaerby, PhD, an assistant professor at the university’s Center for Translational Neuromedicine.
The findings add insight to what happens in the brain during sleep and may help pave the way for new treatments for those who have sleep disorders.
Waves of noradrenaline
Previous research has suggested that noradrenaline – a hormone that increases during stress but also helps you stay focused – is inactive during sleep. So, the researchers were surprised to see high levels of it in the brains of the sleeping rodents.
“I still remember seeing the first traces showing the brain activity of the norepinephrine stress system during sleep. We could not believe our eyes,” Dr. Kjaerby said. “Everyone had thought the system would be quiet. And now we have found out that it completely controls the microarchitecture of sleep.”
Those noradrenaline levels rise and fall like waves every 30 seconds during non-REM (NREM) sleep. At each “peak” the brain is briefly awake, and at each “valley” it is asleep. Typically, these awakenings are so brief that the sleeping subject does not notice. But the higher the rise, the longer the awakening – and the more likely the sleeper may notice.
During the valleys, or when norepinephrine drops, so-called sleep spindles occur.
“These are short oscillatory bursts of brain activity linked to memory consolidation,” Dr. Kjaerby said. Occasionally there is a “deep valley,” lasting 3-5 minutes, leading to more sleep spindles. The mice with the most deep valleys also had the best memories, the researchers noted.
“We have shown that the amount of these super-boosts of sleep spindles, and not REM sleep, defines how well you remember the experiences you had prior to going to sleep,” said Dr. Kjaerby.
Deep valleys were followed by longer awakenings, the researchers observed. So, the longer the valley, the longer the awakening – and the better the memory boost. This means that, though restless sleep is not good, waking up briefly may be a natural part of memory-related sleep phases and may even mean you’ve slept well.
What happens in our brains when we sleep: Piecing it together
The findings fit with previous clinical data that shows we wake up roughly 100-plus times a night, mostly during NREM sleep stage 2 (the spindle-rich sleep stage), Dr. Kjaerby said.
Still, more research on these small awakenings is needed, Dr. Kjaerby said, noting that professor Maiken Nedergaard, MD, another author of this study, has found that the brain cleans up waste products through a rinsing fluid system.
“It remains a puzzle why the fluid system is so active when we sleep,” Dr. Kjaerby said. “We believe these short awakenings could potentially be the key to answering this question.”
A version of this article first appeared on WebMD.com.
FROM NATURE NEUROSCIENCE