Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Neuroscience Page 1 of 11

Does aging make our brains less efficient?

We are an aging population. Demographic projections predict the largest population growth will be in the oldest age group – one study predicted a doubling of people age 65 and over between 2012 and 2050. Understanding aging and prolonging healthy years is thus becoming increasingly important.

Michele Diaz and her team explore the effects of aging on cognition.

For Michele Diaz, PhD, of Pennsylvania State University, understanding aging is most important in the context of cognition. She’s a former Duke faculty member who visited campus recently to update us on her work.

Diaz said the relationship between aging and how we think is much more nuanced than the usual stereotype of a steady cognitive decline with age.

Research has found that change in cognition with age cannot be explained as a simple decline: while older people tend to decline with fluid intelligence, or information processing, they maintain crystallized intelligence, or knowledge.

Diaz’s work explores the relationship between aging and language. Aging in the context of language shows an interesting phenomenon: older people have more diverse vocabularies, but may take longer to produce these words. In other words, as people age, they continue to learn more words but have a more difficult time retrieving them, leading to a more frequent tip-of-the-tongue experience.

In order to understand the brain activation patterns associated with such changes, Diaz conducted a study where participants of varying ages were asked to name objects depicted in images while undergoing fMRI scanning. As expected, both groups showed less accuracy in naming of less common objects, and the older adult group showed a slightly lower naming accuracy than the younger.

Additionally, Diaz found that the approach older adults take to solving more difficult tasks may be different from younger adults: in younger adults, less common objects elicited an increase in activation, while older adults showed less activation for these more difficult tasks.

Additionally, an increase in activation was associated with a decrease in accuracy. Taken together, these results show that younger and older adults rely on different regions of the brain when presented with difficult tasks, and that the approach younger adults take is more efficient.

In another study, Diaz and her team explored picture recognition of objects of varying semantic and phonological neighborhood density. Rather than manipulation of how common the objects presented in the images are, this approach looks at networks of words based on whether they sound similar or have similar meanings. Words that have denser networks, or more similar sounding or meaning words, should be easier to recognize.

An example of a dense (left) and sparse (right) phonological neighborhood. Words with a greater number of similar sounding or meaning words should be more easily recognized. Image courtesy of Vitevitch, Ercal, and Adagarla, Frontiers in Psychology, 2011.

With this framework, Diaz found no age effect on recognition ability for differences in semantic or phonological neighborhood density. These results suggest that adults may experience stability in their ability to process phonological and semantic characteristics as they age.

Teasing out these patterns of decline and stability in cognitive function is just one part of understanding aging. Research like Diaz’s will only prove to be more important to improve care of such a growing demographic group as our population ages.

Post by undergraduate blogger Sarah Haurin

Post by undergraduate blogger Sarah Haurin

Predicting sleep quality with the brain

Modeling functional connectivity allows researchers to compare brain activation to behavioral outcomes. Image: Chu, Parhi, & Lenglet, Nature, 2018.

For undergraduates, sleep can be as elusive as it is important. For undergraduate researcher Katie Freedy, Trinity ’20, understanding sleep is even more important because she works in Ahmad Hariri’s Lab of Neurogenetics.

After taking a psychopharmacology class while studying abroad in Copenhagen, Freedy became interested in the default mode network, a brain network implicated in autobiographical thought, self-representation and depression. Upon returning to her lab at Duke, Freedy wanted to explore the interaction between brain regions like the default mode network with sleep and depression.

Freedy’s project uses data from the Duke Neurogenetics Study, a study that collected data on brain scans, anxiety, depression, and sleep in 1,300 Duke undergraduates. While previous research has found connections between brain connectivity, sleep, and depression, Freedy was interested in a novel approach.

Connectome predictive modeling (CPM) is a statistical technique that uses fMRI data to create models for connections within the brain. In the case of Freedy’s project, the model takes in data on resting state and task-based scans to model intrinsic functional connectivity. Functional connectivity is mapped as a relationship between the activation of two different parts of the brain during a specific task. By looking at both resting state and task-based scans, Freedy’s models can create a broader picture of connectivity.

To build the best model, a procedure is repeated for each subject where a single subject’s data is left out of the model. Once the model is constructed, its validity is tested by taking the brain scan data of the left-out subject and assessing how well the model predicts that subject’s other data. Repeating this for every subject trains the model to make the most generally applicable but accurate predictions of behavioral data based on brain connectivity.

Freedy presented the preliminary results from her model this past summer at the BioCORE Symposium as a Summer Neuroscience Program fellow. The preliminary results showed that patterns of brain connectivity were able to predict overall sleep quality. With additional analyses, Freedy is eager to explore which specific patterns of connectivity can predict sleep quality, and how this is mediated by depression.

Freedy presented the preliminary results of her project at Duke’s BioCORE Symposium.

Understanding the links between brain connectivity, sleep, and depression is of specific importance to the often sleep-deprived undergraduates.

“Using data from Duke students makes it directly related to our lives and important to those around me,” Freedy says. “With the field of neuroscience, there is so much we still don’t know, so any effort in neuroscience to directly tease out what is happening is important.”

Post by undergraduate blogger Sarah Haurin
Post by undergraduate blogger Sarah Haurin

Beyond Classroom Walls: Research as an Undergrad

“Science is slow,” says Duke undergraduate Jaan Nandwani. That’s one of the takeaways from her first experience with scientific research. For Nandwani, being part of a supportive lab makes it all worthwhile. But we’re getting ahead of ourselves. This statement needs context.

Nandwani, a prehealth sophomore, currently conducts research in the lab of neurologist Nicole Calakos, MD, PhD. The Calakos lab is focused on synaptic plasticity: changes that occur at the communication junctions between nerve cells in the brain. The lab researches how the brain responds to changes in experience. They also investigate the mechanistic mishaps that can occur with certain neurological conditions.

A neuron from a mouse brain. From Wikimedia Commons.

As a continuation of an 8-week summer research program she participated in earlier this year, Nandwani has been studying dystonia, a brain disorder that causes uncontrollable muscle contractions. She’s using western blot analysis to determine if the activity of a protein called eIF2α is dysregulated in the brain tissue of mice with dystonia-like symptoms, compared with their normal littermates. It is currently unclear if and when targeting the eIF2 signaling pathway can improve dystonia, as well as where in the brain “selective vulnerability” to the signaling occurs. If Nandwani is able to identify a specific region or time point “in which the pathway’s dysregulation is most predominant,” more effective drug therapy and pharmacological interventions can be used to treat the disorder. 

Outside of her particular project, Nandwani attends lab meetings, learning from and contributing to the greater Calakos lab community. Scientific work is highly collaborative and Nandwani’s experience is testament to that. Along with providing feedback to her own presentations in meetings and answering any questions she may have, Nandwani’s fellow labmates are always eager to discuss their projects with her, give her advice on her own work, and have helped her “develop a passion for what [she is] studying.” They’ve also helped her learn new and improved ways to conduct the western blot process that is so integral to her work. Though she admits it is tedious, Nandwani said that she enjoys being able to implement better techniques each time she conducts the procedure. She also says she is thankful to be surrounded by such a supportive lab environment.

It might seem hard to believe granted the scope and potential impacts of her work, but this is Nandwani’s first experience with research in a lab. She knew when coming to Duke that she wanted to get involved with research, but she says that her experience has surpassed any expectations she had – by far. Though she doesn’t necessarily foresee continuation of research in the form of a career and is more fascinated by clinical applications of scientific research, the experience cannot be replicated within a classroom setting. Beyond the technical skills that Nandwani has developed, she says that the important and valuable mentoring relationships she has gained simply couldn’t be obtained otherwise.

Duke undergraduate Jaan Nandwani doing research in the Calakos lab.

Nandwani hopes to continue in the Calakos lab for the remainder of her time at Duke – that’s two and a half more years. Though she will work on different projects, the quest to pose and answer scientific questions is endless – and as Nandwani said, science is slow. The scientific process of research takes dedication, curiosity, collaboration, failure, and a continued urge to grow. The scientific process of research takes time, and lots of it. Of course the results are “super exciting,” Nandwani says, but it is the experience of being part of such an amazing group of scholars and scientists that she values the most.

By Cydney Livingston

Researchers Urge a Broader Look at Alzheimer’s Causes

Just about every day, there’s a new headline about this or that factor possibly contributing to Alzheimer’s Disease. Is it genetics, lifestyle, diet, chemical exposures, something else?

The sophisticated answer is that it’s probably ALL of those things working together in a very complicated formula, says Alexander Kulminski, an associate research professor in the Social Science Research Institute. And it’s time to study it that way, he and his colleague, Caleb Finch at the Andrus Gerontology Center at the University of Southern California, argue in a recent paper that appears in the journal Alzheimer’s and Dementia, published by the Alzheimer’s Association.

Positron Emission Tomography scan of a brain affected by cognitive declines . (NIH)

“Life is not simple,” Kulminski says. “We need to combine different factors.”

“We propose the ‘AD Exposome’ to address major gaps in understanding environmental contributions to the genetic and non-genetic risk of AD and related dementias,” they write in their paper. “A systems approach is needed to understand the multiple brain-body interactions during neurodegenerative aging.”

The analysis would focus on three domains, Kulminski says: macro-level external factors like rural v. urban, pollutant exposures, socio-economcs; individual external factors like diet and infections; and internal factors like individual microbiomes, fat deposits, and hormones.

That’s a lot of data, often in disparate, broadly scattered studies. But Kulminski, who came to Duke as a physicist and mathematician, is confident modern statistics and computers could start to pull it together to make a more coherent picture. “Twenty years ago, we couldn’t share. Now the way forward is consortia,” Kulminski said.

The vision they outline in their paper would bring together longitudinal population data with genome-wide association studies, environment-wide association studies and anything else that would help the Alzheimer’s research community flesh out this picture. And then, ideally, the insights of such research would lead to ways to “prevent, rather than cure” the cognitive declines of the disease, Kulminsky says.  Which just happens to be the NIH’s goal for 2025.

An Undergraduate Student Grapples with Morality

Existential speculations are normal part of college, and parents shouldn’t worry too much if their child calls home freshman year to speculate on the writings of Immanuel Kant or Sigmund Freud with them. It’s all part of growing up.

But for Shenyang Huang (C’20), these existential questions aren’t just pastimes: They’re work.

As a neuroscience major and a participant in Duke’s Summer Neuroscience Program, Huang has spent eight weeks of his summer in the Imagination and Modal Cognition laboratory researching under Dr. Felipe De Brigard, a three-in-one professor of philosophy, psychology, and neuroscience. Huang has been working at the intersection of those fields with PhD student Matt Stanley to explore some hefty questions about morality and memory.

Shenyang Huang is a rising senior Neuroscience student at Duke. (Image provided by Huang)

The team is grappling with our past mistakes, and how they’ve impacted who we are today. Specifically, how do we remember moments when we behaved immorally? And how do those moments shape the way we think of ourselves?

These questions have been approached from various angles in different studies. One such study, published in 2016 by Maryam Kouchaki and Frencesca Gino, claims that “Memories of unethical actions become obfuscated over time.” Or rather, we forget the bad things we’ve done in the past. According to their study, it’s a self-preservation method for our current concepts of self-worth and moral uprightness.

“I was surprised when I read the Kouchaki and Gino study,” Huang explains. “They claim that people try to forget the bad things they’d done, but that doesn’t feel right. In my life, it’s not right.”

In their two-part study, Stanley and Huang surveyed nearly 300 online participants about these moments of moral failure. They reported memories ranging from slightly immoral events, like petty thievery and cheating on small assignments, to highly immoral incidences, like abusing animals or cheating on significant others. Through questionnaires, the team measured the severity of each incident, how vividly the person recollected the experience, how often the memory would bubble to consciousness on its own, how they emotionally responded to remembering, and how central each event was to the subject’s life.

Their preliminary results resonate more with Huang: Highly immoral actions were recalled more vividly than milder transgressions, and they were generally considered more central in subjects’ life narratives.

“Moral memories are central to one’s sense of self,” Huang says, “and the other paper didn’t discuss centrality in one’s life at all.”

Felipe DeBrigard is an assistant professor of philosophy and a member of the Duke Institute for Brain Sciences. (Les Todd, Duke Photo)

Though contradictory to what Kouchaki and Gino found, the findings have a firm foundation in current psychology literature, De Brigard says. “There are a lot of studies backing the contrary [to Kouchaki and Gino], including research on criminal offenses. People who have committed crimes of passion are known to suffer from a kind of moral PTSD — they constantly relive the event.”

Huang’s study is only one branch of research in a comprehensive analysis of morality and memory De Brigard is exploring now, with the help from the six graduate and eight undergraduate students operating out of his lab.

“Working in a lab with philosophers, psychologists, and neuroscientists, you see different approaches to the same overarching problem,” Huang says. And as he begins to consider PhD programs in neuroscience, this interdisciplinary exposure is a huge asset.

“It’s helpful and inspiring — I can’t take every class, but I can sit and overhear conversations in the lab about philosophy or psychology and learn from it. It widens my perspective.”


by Vanessa Moss

How Many Neuroscientists Does it Take to Unlock a Door?

Duke’s Summer Neuroscience Program kicked off their first week of research on June 4 with a standard morning meeting: schedules outlined, expectations reiterated, students introduced. But that afternoon, psychology and neuroscience professor Thomas Newpher and undergraduate student services coordinator Tyler Lee made the students play a very unconventional get-to-know-you game — locking them in a room with only one hour to escape.

Not the usual team building activity: Students in Duke’s 8-week Summer Neuroscience Program got to know each other while locked in a room.

Bull City Escape is one of a few escape rooms in the Triangle, but the only one to let private groups from schools or companies or families to come and rent out the space exclusively. Like a live-in video game, you’re given a dramatic plot with an inevitably disastrous end: The crown jewels have been stolen! The space ship is set to self-destruct! Someone has murdered Mr. Montgomery, the eccentric millionaire! With minutes to go, your rag-tag bunch scrambles to uncover clues to unlock locks that yield more clues to yet more locks and so on, until finally you discover the key code that releases you back to the real world.

This summer’s program dips into many subfields, in hopes of pushing the the 16 students (most of them seniors) toward an honors thesis. According to Newpher, three quarters of the senior neuroscience students who participated in the 2018 SNP program graduated with distinction last May.

From “cognitive neuro” that addresses how behavior and psychology interacts with your neural network, to “translational neuro” which puts neurology in a medical context, to “molecular and cellular neuro” that looks at neurons’ complex functions, these students are handling subjects that are not for the faint of heart or dim of mind.

But do lab smarts carry over when you’re locked in a room with people you hardly know, a monitor bearing a big, red timer, blinking its way steadily toward zero?

Apparently so. The “intrepid team of astronauts” that voyaged into space were faced with codes and locks and hidden messages, all deciphered with seven minutes left on the clock, while the “crack-team of detectives” facing the death of Mr. Montgomery narrowly escaped, with less than a minute to spare. At one point, exasperated and staring at a muddled bunch of seemingly meaningless files, a student looked at Dr. Newpher and asked, “Is this a lesson in writing a methods section?”

The Bull City Escape website lists creative problem-solving, focus, attention to detail, and performance under pressure as a few of the skills a group hones by playing their game — all of which are relevant to this group of students, many of whom are pre-med. But hidden morals about clarity and strength-building aside, Newpher picked the activity because it allows different sides of people’s personalities to come out: “When you’re put in that stressful environment and the clock is ticking, it’s a great way to really get to know each other fast.”

By Vanessa Moss
By Vanessa Moss

The Adolescent Brain Isn’t so Bad, Really

Adriana Galván, PHD (Photo from the Duke Center for Cognitive Neuroscience Colloquium Series, DIBS)

More often than not, teenagers are portrayed in the media as troublesome, emotionally reactive, and difficult to deal with. They are widely considered to be risk-takers, and prone to making poor choices.

But is taking risks necessarily a bad thing? Should adolescents be seen as bad people? Adriana Galván, PHD, doesn’t think so.

Galván is a neuroscientist and professor at UCLA, where she studies sleep, emotion, learning, stress, and decision-making in the adolescent brain. She came to Duke on Friday, April 5 as part of the DIBS Center for Cognitive Neuroscience’s Colloquium Series.

Humans have an extended period of adolescence, because our brains take a very long time to complete development, Galván said. Adolescence is currently defined as the period between the onset of puberty and the end of developmental plasticity. During this time, teen brains are constantly changing, and these physical changes are linked to socioemotional changes in behavior.

The Brain’s Reward System: meso-limbic pathway shown in green (Photo from WikiCommons: Oscar Arias-Carrión1, Maria Stamelou, Eric Murillo-Rodríguez, Manuel Menéndez-González and Ernst Pöppel)

One of the most prominent differences between adolescent and adult brains can be found in the brain’s reward system. Research has shown that adolescents have higher levels of activation in the mesolimbic system and ventral striatum regions of the brain, areas that are very important in reward processing.

Galván believes that this greater reward system excitability in teenagers may explain why they engage in more risky behavior than adults.

A study done by Galván and her former student, Emily Barkley-Levenson, investigated the stereotype of risk-taking in adolescents. Sure enough, when tested against adults in a gambling game, adolescents were more likely to take risks. However, a closer look at the data suggests that this might not be such a bad thing.

For disadvantageous and neutral gambles, adolescents didn’t differ from adults at all. But when it came to advantageous gambles, adolescents were far more likely than adults to accept the risk. This suggests that risk-taking behavior in teens might actually be adaptive, and put young people at an advantage when it comes to making the choices that lead to innovation and discovery.

Adolescents were also shown to exhibit better learning from outcomes than adults. Adolescence is a period of time where young people are constantly receiving feedback from their environment, and learning about the world around them from social interactions and relationships.

Another of Galván’s students, Kaitlyn Breiner, found that adolescents experienced high levels of emotional distress when their expectations of social feedback were violated. This was true regardless of whether the participants were receiving positive or negative unexpected feedback; they were just as distressed by an unexpected compliment as they were by an unexpected insult. Galván hypothesizes this is because relief is a very powerful emotion, and adolescent participants were looking to find comfort in a validation of their beliefs about their social relationships. It’s comforting to feel like your interpretation of the social world is correct, especially during the shifting world of adolescence.

Adolescents learn about their world through social interactions with friends (Photo from Wikimedia Commons: Glenn Waters)

Galván and her team have also investigated the role of mesolimbic activation in mediating distress.

Following the 2016 US Presidential election, participants in Los Angeles were asked if they felt personally affected by the election. The research team then measured the activation in their nucleus accumbens (a region of the mesolimbic system that plays a role in reward) and looked for symptoms of depression. Of those who reported feeling affected by the outcome of the election, Galván found that people with high activation in their nucleus accumbens had less depressive symptoms than those with low activation in this area. This suggests that high activation of the reward system plays a role in mediating depression. If adolescent brains experience these higher levels of reward system activation, might this protect them from depression?

The bottom line is, adolescents are not bad people, and they aren’t stupid either. In some ways, they may even be smarter than adults. Teens are better at learning from outcomes, more likely to take advantageous risks, and they experience higher levels of activation in their reward system, which could have important implications for resilience. The research shows that teenagers are far more capable – and smarter – than the world believes. Let’s give them a little more credit.

Post by Anne Littlewood, Trinity ’21

The Costs of Mental Effort

Every day, we are faced with countless decisions regarding cognitive control, or the process of inhibiting automatic or habitual responses in order to perform better at a task.

Amitai Shenhav, PhD, of Brown University, and his lab are working on understanding the factors that influence this decision making process. Having a higher level cognitive control is what allows us to complete hard tasks like a math problem or a dense reading, so we may expect that the optimal practice is to exert a high level of control at all times.

Shenhav’s lab explores motivation and decision making related to cognitive control.

Experimental performance shows this is not the case: people tend to choose easier over hard tasks, require more money to complete harder tasks, and exert more mental effort as the reward value increases. These behaviors all suggest that the subjects’ automatic state is not to be at the highest possible level of control.

Shenhav’s research has centered around why we see variation in level of control. Because cognitive control is a costly process, there must be a limit to how much we can exert. These costs can be understood as tradeoffs between level of control and other brain functions and consequences of negative affective changes related to difficult tasks, like stress.

To understand how people make decisions about cognitive control in real time, Shenhav has developed an algorithm called the Expected Value of Control (EVC) model, which focuses on how individuals weigh the costs and benefits of increasing control.

Employing this model has helped Shenhav and his colleagues identify situations in which people are likely to choose to invest a lot of cognitive control. In one study, by varying whether the reward was paired only with a correct response or was given randomly, Shenhav simulated variability in efficacy of control. They found that people learn fairly quickly whether increasing their efforts will increase the likelihood of earning the reward and adjust their control accordingly: people are more likely to invest more effort when they learn that there is a correlation between their own effort and the likelihood of reward than when rewards are distributed independent of performance.

Another study explored how we adjust our strategies following difficult tasks. Experiments with cognitive control often rely on paradigms like the Stroop task, where subjects are asked to identify a target cue (color) while being presented with a distractor (incongruency of the word with its text color). Shenhav found that when subjects face a difficult trial or make a mistake, they adjust by decreasing attention to the distractor.

The Stroop task is a classic experimental design for understanding cognitive control. Successful completion of Stroop task 3 requires overriding your reflex to read the word in cases where the text and its color are mismatched.

A final interesting finding from Shenhav’s work tells us that part of the value of hard work may be in the work itself: people value rewards following a task in a way that scales to the effort they put into the task.

Zapping Your Brain Is Dope

Emerging technology has created a new doping technique for athletic performance that is, as of now, perfectly legal.

Coined “neuro-doping,” this method sends electric current through one’s brain to facilitate quicker learning, enhanced muscular strength, and improved coordination. Use of this electronic stimulus has taken off in the sports world as a replacement for other doping methods banned by the World Anti-Doping Agency (WADA). Because it’s relatively new, WADA has yet to establish rules around neuro-doping. Plus, it’s virtually undetectable. Naturally, a lot of athletes are taking advantage of it.

Image result for doping

One specific method of neuro-doping is known as Transcranial Direct-Current Stimulation (tDCS). It works by sending a non-invasive and painless electrical current through the brain for around three to 20 minutes, in order to excite the brain’s cortex, ultimately increasing neuroplasticity (Park). This can be done commercially via a headset like device for $200.

Image result for transcranial direct current stimulation headset
The Halo Sport

Weight lifters, sprinters, pitchers, and skiers are just some of many types of athletes who can benefit from tCDS. By practicing with these headphones on, new neural pathways are constructed to help their bodies achieve peak performance. Dr. Greg Appelbaum, director of Opti Lab and the Brain Stimulation Research Center, says it’s especially useful for athletes where technique and motor skills triumph — such as a sprinter getting out of the blocks or an Olympic ski jumper hanging in the air. Top-tier athletes are pushing that fine limit of what the human body can accomplish, but neuro-doping allows them to take it one step further.

Neuro-doping has other applications, too. Imagine insanely skilled Air Force pilots, surgeons with exceptionally nimble hands, or soldiers with perfect aim. tCDS is being used to make progress in things like Alzheimer’s and memory function because of its impact on cognitive functioning in the forms of increased attention span and memory. You could even learn the guitar faster.

In this sort of context, it’s a no brainer that neuro-doping should be taken advantage of. But how ethical is it in sports?

The precedent for WADA to ban a substance or technique has been based on meeting two of the following three criteria: (1) drugs or tools that likely enhance performance to secure a winning edge; (2) drugs or tools that place athletes’ health at risk; (3) any substances or techniques that ruin the “spirit-of-sport” (Park). Lots of research has shown tCDS is pretty legit. As for health risks, tCDS is still in the experimental stage, so not much can be said about its side effects. Ethically, it causes a lot of controversy.

Many issues come into play when thinking about allowing athletes to neuro-dope. Given its similarities with other popular drugs, tCDS could introduce unfair advantages. Furthermore, not everyone may have access to the technology, and not everyone may want to use it. However, it’s important to note that sports already have unfair advantages. Access to things like proper coaching and nutrition may not be a reality for everyone. Sports are just inherently competitive.

Back when baseball players doped, it was awesome to watch them crush balls out of the park. Reintroducing performance enhancement through tCDS could mean we start seeing mountain bikers launching insane air and world records being smattered. The human body could achieve newfound heights.

Are the benefits worth it? Does neuro-doping ruin the “spirit of the sport?” Regardless of these important questions, tCDS is a fascinating scientific discovery that could make a difference in this world. So, what do you think?

Will Sheehan
Post by Will Sheehan

Park, Cogent Social Sciences (2017), 3: 1360462
https://doi.org/10.1080/23311886.2017.1360462

Dolphin Smarts

Imagine you are blindfolded and placed into a pool of water with a dolphin. The dolphin performs a movement, such as spinning in a circle, or swimming in a zig-zag pattern, and your task is to imitate this movement, without having seen it. Ready, go. 

Sound impossible? While it may not be possible for a human to do this with any accuracy, a dolphin would have no problem at all. When cognitive psychologist and marine mammal scientist Kelly Jaakkola gave this task to the dolphins at the Dolphin Research Center in Florida, they had no problem at all copying a human’s behavior. So how did they do it? Jaakkola thinks they used a combination of active listening and echolocation.

How smart are dolphins? (Photo from Wikimedia Commons: Stuart Burns)

Humans love to claim the title of “smartest” living animal. But what does this mean? How do we define intelligence? With a person’s GPA? Or SAT score? By assigning a person a number that places him or her somewhere on the scale from zero to Einstein? 

Honestly, this is problematic. There are many different types of intelligence that we forget to consider. For example, Do you know that five is less than seven? Can you remember the location of an object when you can’t see it? Can you mimic a behavior after watching it? Are you capable of cooperating to solve problems? Can you communicate effectively? All of these demonstrate different intelligent skills, many of which are observed in dolphins.

Needless to say, dolphins and humans are entirely different creatures. We have different body plans, different ways of interacting with the world, and different brains. It has been 90 million years since we shared a common ancestor, which is why the things we do have in common are so fascinating to researchers. 

Like us, dolphins understand ordinality. When presented with two novel boards with different numbers of dots, dolphins at the Dolphin Research Center chose the smaller number 83 percent of the time. But unlike us, they weren’t counting to solve this problem. When they were shown boards that represented consecutive numbers, the dolphins struggled, and often failed the task.

Similar to humans, dolphins understand that when objects are hidden from view, they still exist. At the Dolphin Research Center, they could easily remember the location of toy when a trainer hid it inside a bucket. However, unlike humans, dolphins couldn’t infer the movement of hidden objects. If the bucket was moved, the dolphins didn’t understand that the toy had moved with it.

Dr. Jaakkola presents to a packed room of Duke students

While they may not be physicists, Jaakkola has shown that dolphins are stellar cooperators, and amazing at synchronous tasks. When asked to press an underwater button at the same time as a partner, the dolphins pushed their buttons within 0.37 milliseconds of each other, even when they started at different times. As the earlier example shows, dolphins can also imitate incredibly well, and this skill is not limited to mimicking members of their own species. Even though humans have an entirely different body plan, dolphins can flexibly use their flipper in place of a hand, or their tail in place of legs, and copy human movements.

It is believed that dolphins evolved their smarts so that they could navigate the complex social world that they live in. As the researchers at the Dolphin Research Center have shown, they possess a wide array of intelligent abilities, some similar to humans and others entirely different from our own. “Dolphins are not sea people,” Jaakkola warned her audience, but that’s not to discount the fact that they are brilliant in their own way. 

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