On October 4th, 2018 we learned about

Piano lessons prime kids’ listening to be better readers

Schools with tight budgets often treat their art classes as expensive luxuries, cutting them in order to focus on students’core educational needs like math and literacy. Researchers from MIT and Beijing Normal University have found that these strategies may not be as cost effective as they intend to be, and that arts, or more specifically music classes, can help young students with their reading more than practicing reading directly. This isn’t because reading quarter notes somehow teaches kids their ABCs, as it’s tied more to beginner readers’ need to approach language as a spoken form of communication.

There have been a variety of cognitive skills tied to music training. Musicians generally perform better auditory processing, deciphering speech amid background noise, and even reading comprehension. However, these correlations were generally made from retroactive surveys that weren’t enough for school administrators to plan a budget around. So when officials in Beijing were trying to assess how cost-effective music lessons were for their young students, it was a unique opportunity to really test how music boosts kids’ ability to read.

Experiments with real-world readers

For six months, 74 four- and five-year-olds were enrolled in one of three programs. One group took three, 45-minute piano lessons each week, another spent that time doing extra reading lessons, while the last group was left to their own devices with no extra classes. In addition to having their reading scores tested, these kids also had their brain activity measured with electroencephalography (EEG). Kids learning to play the piano showed stronger responses to changes in sounds’ pitch than other students, a fact that helps explain what researchers found in their reading scores.

After six months, the students who studied music showed the greatest improvement in one particular part of their reading— they could differentiate between single consonant sounds better than either of the other test groups, and their reading scores benefited as a result. The kids who had extra reading classes instead of music raised their scores around the same amount, although most of their improvements were tied to differentiation between vowel sounds instead of consonants. In both cases, it’s clear that beginner readers are greatly dependent on the sounds of words in order to understand what they read, instead of simply gleaning meaning from ink on a page. By training their ear for the kinds of sounds through music or other practice, students’ reading ability improved, especially compared to the kids who had no special classes and showed no real change over six months time.

Teaching two skills at once

Assuming the costs are somewhat equivalent, researchers felt that the gains seen in music students show how cost-effective music classes can be. Rather than competing for time and money against students’ reading development, this shows that time at the piano is another way to help get kids reading at a young age. While it wasn’t covered directly in the study, the fact that the music students also finished up being able to play music seems like an attractive ‘bonus’ as well.

Source: How music lessons can improve language skills by Massachusetts Institute of Technology, Medical XPress

On September 26th, 2018 we learned about

Humans may be wired to live lazily, even if it contributed to the extinction of other hominids

It’s probably embarrassingly easy to come up with personal examples of being lazy. I admit that I’ve driven distances that were easily reachable on foot or on a bike. My kids routinely wear their shirts backwards, even after their mistake is pointed out to them. My wife seems to be only vaguely aware of the family’s laundry hamper. Each of these examples of sloth probably doesn’t amount to much in isolation, but over time they can certainly add up to rather extreme consequences. In the case of Homo erectus, researchers even think being lazy may have played a role in our fellow primates’ extinction. This isn’t great news, as modern Homo sapiens also struggle with laziness, and there’s a chance that we may not be able to ever really be rid of it.

No effort to avoid extinction

As far as we know, H. erectus didn’t go extinct because they wouldn’t deal with their laundry. There is evidence, however, that they did a very poor job managing the resources available to them, even when it surely reduced their quality of life. Stone tools excavated in the Arabian Peninsula were found to be made of very low quality rock fragments, despite an abundance of higher-quality materials within walking distance of the dig site. Unlike ancient Homo sapiens or Neanderthals that apparently transported high-quality materials for miles in order to craft better tools, the H. erectus craftsmen were confusingly content to just use whatever pieces of rock rolled down the hill into their camp.

Being slightly inefficient became a bigger problem for H. erectus as the climate started to shift around them. Researchers found that at time periods when food sources were being shaken up by changes in the environment, H. erectus didn’t seem to respond in any meaningful way. Their tool design and other survival strategies were apparently conservative to the point of being static, leaving them to the complete mercy of the droughts that probably brought about their demise.

Just like our ancestors who did go that extra mile to make better tools, modern humans would surely be protected from this degree of laziness, right? As a species, we’d never sit on our hands while our world’s climate changed around us.

Right?

Internal inertia

If it’s too early to know how closely modern Homo sapiens are willing to follow H. erectus‘ example, we do have evidence that humans are physically less active than they were in the past. Most of us don’t need to hunt or gather our own food anymore, giving us plenty of opportunities to lazily sit on the couch for hours on end (although even modern hunter-gatherers sit down for nearly half their day). Researchers following these trends don’t think it’s just that we’ve lost the will to move or anything, it’s just that being sedentary can, in the right context, be part of a successful survival strategy. Like a carnivore who sleeps nearly every hour that they’re not hunting, humans seem to have inherited a predisposition to try to save our energy whenever we get the chance.

This model may seem intuitive, but researchers recently tested these instincts on a neurological level. Test participants were, appropriately enough, tasked to play a video game that required them to identify images as either active or inactive physical activities. Most people were actually faster to click pick out the images of running or jumping, but brain scans of participants painted a different picture of these responses. Electroencephalograms (EEG) showed that more of the brain had to work to identify images of activity, whereas it was literally easier for the brain to identify images of lazing around on the couch. It seems that even imagining being lazy takes less effort than imagining being active.

So are we doomed to start making worse tools because we can’t be bothered to get off the couch? Researchers said that it’s hard to block out these automatic patterns entirely, but if we’re aware of these cognitive biases we can probably train ourselves to overcome them. It’ll just take work to do so, so maybe we should try tackling it tomorrow…

Source: Laziness helped lead to extinction of Homo erectus by Australian National University, Science Daily

On September 24th, 2018 we learned about

Zebra finches studying songs demonstrate pros and cons of social and solo learning

Despite remembering how annoying it was to hear it as a kid, I still nag my kids about the importance of practicing a new skill. There may be some debate about how much practice is needed to learn a particular task, but there’s little doubt that our brains learn through repetition, piecing together the right and wrong way to do something each time we attempt it. This might not be terribly motivating if you’re feeling frustrated with your piano or swim practice though, especially when you feel like your practice isn’t making any difference in your abilities. As it turns out, there may be a faster way to learn a new skill, although it as some annoyed zebra finches learned, it comes with cost.

Songbirds like a zebra finch (Taeniopygia guttata) are born with the anatomy to sing, but they don’t instinctually know the repertoires they’ll perform throughout their lives. They must learn particular songs, and seem to rely on listening to their older relatives, building their own version of a tune over time. Some songbirds have more direct mentors for their singing, but they can also piece together a song on their own if need be. These two styles of learning allowed researchers from the University of Zurich to devise an experiment to see if one kind of learning was more advantageous than the other. Essentially, do the finches who learn by example do better than those that have to figure things out through trial and error?

Speedier but shallower learning

While zebra finches definitely learn songs from each other, the first part of the experiment needed the birds to actively compare songs they were listening to. Birds were tasked with learning to differentiate between either “long” or “short” songs. Half the birds could observe other finches work through the same process, while the other half were left to figure out the comparison on their own. This made a huge difference, as birds that could learn from the efforts of their peers could successfully compare the songs after only 900 attempts, while birds who had to work on their own required closer to 4,700. Clearly, the social nature of zebra finches gives them a huge boost, allowing them to benefit from the efforts of other birds.

A second phase of the experiment found that the apparent advantage of social learning might not be better in every circumstance though. After learning the long and short songs, finches were offered a perch where they could see other birds but listen to two other recorded bird songs. These songs were similar to what had already been practiced, except that the longer song in this case was followed by an unpleasant puff of air in the listener’s face. Researchers then tracked how long the finches took to learn this new association and be ready to move their head out of the way of the harmless but annoying negative reinforcement.

The finches that learned from their peers in the first phase of the experiment didn’t fare as well in this scenario. On average, they took 3,600 tries before they put together the clues about when they’d be puffed in the face. The birds that had to figure out the first phase on their own did significantly better, requiring only 800 tries to learn this new task. So while they took longer to figure out the songs on their own, these birds seemed to have a better grasp of the underlying concepts which allowed them to generalize and reuse those ideas in new situations.

Information versus understanding

We can’t necessarily say that all learning can be compared to a zebra finch trying to avoid a puff of air in its face. However, researchers did put together a model that could help explain how these two sets of behaviors work on a neurological level. They believe that the finches that learned the first task by watching peers probably ended up with a broad but relatively weak set of synaptic connections associated with comparing the songs. In addition to forming connections in their brain that helped them listen to different song structures, they may have also been recording less relevant information, such as how their peers were sitting, if it was time to eat or not, etc. All that left them with a good blueprint for that first scenario, but it fell apart when too many of those irrelevant details were changed. In contrast, the birds that had to figure out the first songs on their own probably retained fewer details, but had a more robust foundation to build on in the second phase of the experiment. They likely had fewer synaptic connections in their brain, but what they had was strong and ready to work with new information in a more useful way.

None of this diminishes the need for practice. Many schools purposely try to use both forms of learning, asking students to both mimic a tutor and spend time in more experimental, trial-and-error activities. The former may help get someone up to speed a little quicker, which is great for a sense of accomplishment, but it turns out those difficult periods of more iterative learning will likely lead to a deeper understanding of an idea for future use.

Source: How birds learn, Science Daily

On July 19th, 2018 we learned about

Without climate control, heat waves take a measurable toll on our cognitive abilities

On the hottest days of summer, I generally just feel like giving up. By later afternoon, temperatures in my older building easily surpass whatever’s happening outside, a factor compounded by the outdated myth that “nobody needs an air conditioner in northern California.” The net effect is a feeling of tired fogginess, making concentration on just about any task rather difficult. While this may sound like a lot of whining (it is!) scientists have actually been able to quantify the cognitive hit inflicted by seasonal spikes in heat, pointing out that they take a measurable toll on all of us.

Testing the effects of living in high temperatures

Unusually high temperatures associated with heat waves have long been known to be detrimental to human health, although most research on heat has focused on cases when it’s literally a danger to people’s lives. To investigate cognitive issues possibly experienced by everyone, researchers purposely skipped at-risk populations like infants and the elderly, working only with healthy college students. In theory, any issue that would affect a 22-year-old would probably be an issue for 30- and 40-year-olds as well. The only other criteria that mattered was whether or not each student had air-conditioning in the dormitory where they lived.

Every day of the study, test participants were asked to take a few cognitive tests when they woke up in the morning. The tests included tasks like quickly reading the names of colors with letters displayed in conflicting hues, which is a long-standing way to asses how well someone can filter relevant information in a hurry. They were also asked to do some math and memory tests, giving researchers a range of performance metrics to compare. To make sure environmental conditions were also comparable, test subjects’ rooms were outfitted with temperature, carbon dioxide, humidity and noise sensors. Physical activity and sleep were also tracked with a wearable device.

Extra time and additional errors

After five days of normal temperatures, there was a spike in the area’s heat index. Almost immediately, students living without air conditioning started showing a decrease in cognitive performance. They took 13.4 percent longer in deciphering the color words, and also had 13.3 percent more errors in their math tests. Even after the heatwave broke and the outside world returned to normal, much of that heat was retained indoors, extending the impact of overheated students’ low scores.

Anyone who has lived through unusually hot days won’t be surprised by this, but anecdotally hot homes don’t help science diagnose health problems shape policy. By measuring the significant impact heat has one people’s ability to handle cognitive tasks, this study reveals that rising global temperatures may be causing more immediate and widespread problems than people realized. It’s practical to demand air conditioning for every hot home on the planet, but we may need to further prioritize heat-shedding designs in future construction, plus look for ways to mitigate possible problems caused by people too hot to think clearly.

Source: Extreme heat and reduced cognitive performance in adults in non-air-conditioned buildings by Harvard T.H. Chan School of Public Health, Medical Xpress

On June 25th, 2018 we learned about

Our brains reward learning unless we expect the news to be negative

As far as your brain is concerned, this article may be the neurological equivalent of a pastry or lollipop. It’s not that reading these words will tickle your taste-buds, but if you learn something the same reward centers in your brain that give you the sensation of ‘enjoyment’ when eating sugary snacks will be activated. With an incentive like this, it’s hard to imagine then why people ever thought that ignorance could be “bliss,” since we’d be cheating ourselves out of a bit positive neurological feedback by avoiding new information. Why isn’t all news apparently worth knowing?

Nobody likes learning about losing the lottery

To try to figure out when people do and do not enjoy obtaining new information, researchers invited 62 volunteers how much they wanted to know about a laboratory-controlled lottery. Every participant had a chance to win this experimental game, and they were also informed if the odds were good or bad for that particular round of the lottery. The key to the experiment was how people responded to a chance to learn more about each lottery. Most participants were more interested in hearing news about a lottery they thought they had a chance of winning, turning down information about rounds with worse odds.

A little over half of these participants also had their brain activity scanned so that researchers could look for differences in how key anatomy responded while these choices were made. When a participant thought they’d be hearing good news, agreeing to hear more about a lottery correlated with an increase in activity in the nucleus accumbens and ventral tegmental areas of the brain. When bad news was more likely, these areas did not respond, essentially removing some motivation to obtain new information.

Enjoyment based on expectations

So if people like to pursue good news because it feels good, we also seem to lack a motivation to hear bad news, even beyond the ramifications of the news itself. Indeed, brain scans found that the reward-center activity was largely tied to people’s expectations about the lottery news, and was independent of later reactions to news about actually winning or losing the lottery. This kind of feedback may help explain why people seem to illogically avoid receiving negative but helpful information, such as a diagnosis from a doctor about an ailment. Obviously there will always be bad news in the world, but it seems that shaping our expectations may help it feel pleasant enough to enjoy hearing about.

Source: How your brain decides between knowledge and ignorance, EurekAlert!

On June 12th, 2018 we learned about

Students do better in school when they get frequent breaks from extended instruction

One of the best ways to help kids get more out of their time in the classroom is to spend less of that time teaching. A series of 45-minute lessons broken up by 15-minute recesses seems to have a great effect students’ concentration, enabling greater student engagement for each segment of the day. At first glance, it may sound like a ridiculous amount of time spent out on the playground, but schools in Finland, controlled studies and pilot programs in the United State all suggest that expecting kids to stay focused for hours at a time may not be worth the trouble.

Giving brains a break

In Finland, elementary students are given 15 minutes after each 45-minute lesson to head outside and take whatever kind of break they need. When the students return to the classroom, they’re generally ready to take on the next lesson without much hesitation or time spent getting everyone back on track. Because these recesses are outdoors in rain or shine, it was originally assumed that the physical activity involved was the secret to student’s concentration- that they were essentially getting their wiggles out before taking on a new task. However, experiments in classrooms in the United States found that physical exertion might not be necessary, as even breaks inside the classroom made a difference in student performance.

The key mechanic seems to be more closely tied to how our brains learn and retain new information. If running around a playground isn’t strictly necessary, it seems that simply taking a break from learning is. Various durations of lesson-time have been tested, and 45 minutes seems to be the most students can handle before their brains are essentially full. By having a short time for less-structured thought, students seem to be able to process and remember new information more easily. This mirrors the benefits of taking a nap or getting a good night’s sleep to better retain information.

Aerobics for academics

This isn’t to say that kids don’t benefit from moving around during their breaks. A separate study has found that kids with better physical fitness had more gray matter in their brains. What’s more, this increased brain volume correlated with better academic performance in school, particularly with language tasks. In particular, cortical and sub-cortical regions of the brain were larger in kids with better aerobic and motor function, although it’s not clear what mechanism is driving this boost.

In an era when American education is very concerned with test scores, rigor and notions of personal “grit,” giving kids a recess every 45 minutes may seem like a step in the wrong direction (if you choose to ignore the improved scores and behavior.) However, it may be that elementary schools adopting this schedule are simply falling in line with the adult world. Meetings, college lectures and even television shows are mostly expected to require around an hour of concentration, so really we just need to let our younger kids sync up with the demanding schedules adults make for themselves.


My third-grader asked: How long is a school day in Finland? Do they go to school all year?

While it might be intuitive for Finnish kids to make up their “lost” break time in other ways throughout the year, they don’t seem to worry about it. Schools generally start between 8:00 and 9:00 am, getting out between 1:00 to 2:00 pm. Finns also get summer and Christmas holidays, going to school around the same number of days as many American schools.  The important twist is that this schedule with only 25 hours of instruction a week seems to work really well, as Finish schools are considered to be some of the best in the world.

Source: How Kids Learn Better By Taking Frequent Breaks Throughout The Day by Timothy D. Walker, Mind/Shift

On May 27th, 2018 we learned about

Our memories and imagination may make nouns the most mentally demanding part of speech

Some things are hard to say, but according to an easily quantifiable metric, “I’m sorry” and “I love you” are easy. While there may be emotional difficulties and sharing one’s feelings, none of those words are all that difficult, because non of them are common nouns. A study of human speech across nine languages from around the world has found that all humans are most likely to show a bit of cognitive strain when trying to say the names of specific nouns more than any other part of speech. In a weird way, the issue might come down to our brain’s attempt to familiarize ourselves with what we’re saying before we say it.

The study analyzed recorded conversations from Mexico, Siberia, the Himalayas, the Amazon and the Kalahari Desert. While the specific grammar and vocabulary of these languages obviously differed, a commonality turned out to be how much people hesitate before saying a noun in the middle of a sentence. No matter if someone paused silently or with an “uh” or “um,” they were 60 percent more likely to take an extra moment before saying a noun than a verb. Even difficult or unfamiliar verbs weren’t this likely to require a pause, suggesting that there was something about how a noun is handled in the brain that makes us take an extra moment.

Stopping to see what we’re saying

Researchers suspect that these pauses may be due to our brains trying to conceptualize nouns as we try to say them. When we think of something, our brain brings that information into our working memory, often “seeing” it in our mind’s eye. So when we say “dog,” our brain will give us at least an abstract image of a dog, and that moment of internal observation may cost us enough time that we will need to break the rhythm of a spoken statement. As further evidence of the extra effort nouns require, researchers point out that we often avoid restating actual nouns in spoken conversation, replacing them with pronouns like “it” and “that” as much as possible. Verbs apparently aren’t so taxing, as we they don’t cause us to pause, even if we have to keep explicitly using a verb over and over.

Some of this may be eventually confirmed by observing the brain activity of people during casual conversations, looking at how much one’s own speech activates your memory and visual cortex. The fact that these patterns were so widespread suggests that a pattern will turn up though. Having analyzed over 288,848 words in nine languages, researchers are confident that these pre-noun pauses are something universal to human cognition, rather than weird tics of a specific culture’s customs or grammar.

Source: Why You Say 'Um' Before Certain Words by Mindy Weisberger, Live Science

On May 17th, 2018 we learned about

Narrowing down the reasons some people have a harder time with rules and requests

My son is currently in a difficult place, as he has decided to care deeply about being “the boss” while also being five years old. So as much as he’d like to dictate the terms of bedtime or timing of dinner, there are many moments when we can’t agree with the demands and judgments of a pre-schooler. There are signs that, as he grows older, he’s becoming a bit more understanding about when it’s appropriate to cede control to the adults around him, but there’s also a chance that he may be a naturally control-averse person. It’s a mindset that everyone’s encountered from time to time, as we all have moments where expressing defiance is somehow more important than solving the problem at hand, and yet we don’t really know much about how it manifests in our brains. Researchers are getting closer, but pinning down what makes some people have a harder time following “the rules” is proving to be a difficult task.

When being asked for something backfires

If you ask people to share their thoughts on freedom, rules and autonomy, you won’t actually get very far. Most of us, from age five to age fifty, generally feel like making our own choices is a pretty good idea, even if we don’t back those opinions up in our behavior. To come up with a more objective definition of control-averse behavior, researchers had volunteers play a money-trading game in an fMRI, observing brain activity while also looking for patterns in the way people conducted themselves when they weren’t explicitly thinking about if they were “the boss” or not.

Most participants were fairly generous with their partner when playing the game. Likewise, most participants didn’t like their generosity being questioned. During some rounds of “trading,” people’s partners would request a minimum amount of money to be handed over. Almost every participant balked at these requests, complying but handing over less money than if they hadn’t been asked. So for example, if a test subject would have normally shared $15, a request for $10 would spur the subject to share less, maybe only giving $10 or $11 that round. The more control-averse someone was, the more they were likely to reduce their generosity. When asked further questions about their motivations, people who were more control-averse also reported that they were more bothered by the implied lack of trust in their partner’s request as well as a general distrust if they didn’t understand why their partner would ask for a minimum amount. More than ideas about freedom, it seemed that the issue was in understanding the partner’s motivations.

A confusing basis in the brain

Since these behavior patterns were operating on a spectrum, with some people having more pronounced reactions to minimum requests than others, it still wasn’t enough to really define control-aversion. Fortunately, the data from the fMRI scans of participants’ brains helped find a more tangible clue, as control-averse people also showed pronounced activity in the inferior parietal lobule and dorsolateral prefrontal cortex. Those brain regions don’t explain everything at this point, as they linked to everything from math to moral decision-making, but they at least offer a more objective metric than asking for people’s opinions. As researchers look into these particular bits of anatomy further, there’s speculation that the activity seen in this study is the result of a person coming to terms with their own motivations and outside stimuli that they perceive as being in conflict with their goals, even if they’re just a minimum request.

It’s worth noting that as much as control-aversion sounds like a negative (and feels negative when its coming from a tired five-year-old), it’s not necessarily a bad trait to have. There are times when questioning authority or dogma can provide important leadership, helping the rule-breaker and everyone around them. However, in some contexts it obviously causes problems, leading people do to the clash with rules or laws for what seems like a very unnecessary reason.

Source: Why Some People Just Can't Have a Boss: Study Reveals Brain Differences by Bahar Gholipour, Live Science

On May 15th, 2018 we learned about

Researchers use RNA to move memories between snails’ brains

On a practical level, our brains require experience to learn and remember new information. As far as scientists can tell, that information is encoded in a network of synapses, or the connections between brain cells, in various combinations. This structural aspect of memory seems to require that brain cells construct synapses themselves, negating any chance of having new memories being imprinted or injected into the brain all at once. However, researchers are investigating other forms of information found in the brain, focusing on RNA molecules inside brain cells, instead of the connections between those cells. This has opened up some intriguing possibilities, including the ability to transfer memories from one brain to another.

Purposes beyond building proteins

RNA is a complex protein structure that plays a number of roles in cell functionality. It’s most commonly associated with transferring instructions from a cell’s DNA to actual protein production, but researchers are realizing that that is only one of its jobs in the body. To see if it can carry information about an individual animal’s experiences, researchers tried gently scaring some snails to see if RNA could hold information from a memory as well.

The experiment started with marine snails called California sea hares (Aplysia californica) which were given small electric shocks. As the research lead Prof David Glanzman, made a point to specify, the shocks weren’t strong enough to cause harm the snails, and were really only meant to get them to feel the need to retreat from a physical stimulus. After a bit of “training,” zapped snails would retreat from a gentle poke for as long as 40 seconds, while untrained snails would pull back only for a moment.

Injecting information

Once that experience-dependent behavior was established, researchers extracted RNA from brain cells of both groups of snails. The RNA was then injected into the brains of a third batch of snails who had yet to be poked one way or the other. Snails receiving “unzapped” RNA didn’t really change their behavior, reacting only briefly to gentle pokes from researchers. Snails who received RNA from a zapped snail had a bigger response, retreating from physical stimuli as if they had been trained to avoid shocks themselves. The difference in the RNA donors’ experience seemed to control how the recipient snail reacted as if they’d formed a memory on their own.

This seems like a big step towards injectable knowledge, but nobody is about to pick up a new skill in moments quite yet. Other neuroscientists point out that while this study suggests a role for RNA in memory, it doesn’t rule out the importance of synapses. Also, since snails only have 20,000 brain cells, there’s a good chance that the cognitive demand of retreating from a shock isn’t exactly on par with how our brains’ 100 billion brain cells handle new data. Still, it seems that some kind of information was shared via neurons’ RNA, demonstrating a need for further investigation.


My third-grader-asked: Did the first snail that got zapped then forget it got zapped when they took out its RNA?

This wasn’t mentioned, although memory removal would certainly be an interesting wrinkle in a world of injectable information. However, since researchers probably weren’t targeting a single brain cell in the snail’s brain, some memory of being zapped would be left behind in other copies of that RNA memory, assuming that’s how this was all working in the first place.

There also didn’t seem to be a problem with choosing which cells should recieve the RNA injection in the recipient snails, indicating that the “memory” didn’t need to be added to one cell in particular. That may be thanks to the relative simplicity of a snail brain, or that RNA memories are rather general in scope. Maybe they actually trigger physiological responses more than encode details of a specific moment in a snail’s life?

Source: 'Memory transplant' achieved in snails by Shivani Dave, BBC News

On May 6th, 2018 we learned about

Brain scans of crocodiles suggest that even our ancient ancestors could have appreciated listening to Bach

One of the most important parts of getting good data from an MRI is that the subject hold as still as possible, even when being asked to perform a task. This will ensure that the resulting images are clear and crisp, allowing researchers to get more precise data about how anatomy functions, from watching a dye circulate through a kidney to watching changes in oxygenation of specific brain structures in response to stimuli. It’s also a good idea for the subject to avoid biting the MRI technicians, particularly when the subject is a Nile crocodile.

Brains built to parse complex sounds and patterns

With a few extra precautions, such as light sedatives for the juvenile crocodiles (Crocodylus niloticus), researchers have managed to get the first scans of crocodile brains in action. They were presented with variety of stimuli intended to activate specific portions of their brains, such as visual processing centers in response to flashing green or red lights. Auditory responses were first tested with basic, synthetic tones at either 1,000 or 3,000 Hz. However, those sounds were then followed up with the more complex sounds of Johann Sebastian Bach’s Brandenburg Concerto No. 4, a composition used in many animal studies to see if the test subject differentiates between random beeps and a complex, structured series of sounds.

It would appear that the crocodiles did appreciate the music. While the beeps stimulated some auditory centers in the crocodiles’ brains, the concertos were processed by a wider set of brain structures, indicating that more cognition was taking place to unpack those sounds. The particular patterns weren’t completely novel, as they roughly followed the activity seen in birds or mammals when they listen to Bach. Of course, considering how distantly related crocodiles are to mammals, this is quite significant. Crocodiles last shared a common ancestor with birds around 240 million years ago, and mammals 320 million years ago. While it’s possible that this neurological pattern has evolved more than once, it’s probably more likely that it is something all these groups of animals inherited from a common ancestor as far back as the Carboniferous period, and is thus shared across all mammals, birds and reptiles.

Scanning brains in cold-blooded bodies

Of course, an appreciation of complex sounds and patterns may even be older than that, but we’d need to get more distantly related animals into an MRI to find out. Fortunately, this study has helped pave the way for future brain scans, particularly with the challenges of scanning cold-blooded animals like reptiles, amphibians and fish. MRI images don’t detect electrical activity between brain cells, instead showing where oxygen is being depleted in the brain. This is partially dependent on the animal’s body temperature, which is easier to deal with in mammals and birds since our warm-blooded bodies maintain a stable temperature on their own. The crocodiles required a lot of careful adjustments though, since even the MRI machine itself would raise the crocodiles’ temperature enough to change how they were using oxygen. With that experience under their belt researchers now hope to use these lessons with other creatures to discover which creatures’ brains can’t handle classical music.


My third grader asked: This didn’t hurt the crocodiles, did it?

The crocodiles didn’t experience pain, and apparently showed little signs of discomfort. While they were sedated, and their mouths and tails bound, the crocodiles seemed to be quite comfy when in the confines of the scanner tube. Once they were inside, they turned out to be very cooperative test subjects, holding still during the scanning process. In the end, they followed all the aforementioned guidelines, including the bit about not biting anyone.

Source: What Scientists Saw When They Put a Crocodile in an MRI Scanner and Played Classical Music by George Dvorsky, Gizmodo