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Animal behavior research is getting better at keeping observer bias from sneaking in – but there’s still room to improve

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theconversation.com – Todd M. Freeberg, Professor and Associate Head of Psychology, of Tennessee – 2024-05-03 07:16:49

What you expect can influence what you think you see.

Auscape/Universal Images Group via Getty Images

Todd M. Freeberg, University of Tennessee

Animal behavior research relies on careful observation of animals. Researchers might spend months in a jungle habitat watching tropical birds mate and raise their young. They might track the rates of physical contact in cattle herds of different densities. Or they could record the sounds whales make as they migrate through the ocean.

Animal behavior research can fundamental insights into the natural processes that affect ecosystems around the globe, as well as into our own human minds and behavior.

I study animal behavior – and also the research reported by scientists in my field. One of the challenges of this kind of science is making sure our own assumptions don’t influence what we think we see in animal subjects. Like all people, how scientists see the world is shaped by biases and expectations, which can affect how data is recorded and reported. For instance, scientists who in a society with strict gender roles for women and might interpret things they see animals doing as reflecting those same divisions.

The scientific corrects for such mistakes over time, but scientists have quicker methods at their disposal to minimize potential observer bias. Animal behavior scientists haven’t always used these methods – but that’s changing. A new study confirms that, over the past decade, studies increasingly adhere to the rigorous best practices that can minimize potential biases in animal behavior research.

Animal behavior research is getting better at keeping observer bias from sneaking in – but there’s still room to improve

Adding up?

Karl Krall/Wikimedia Commons

Biases and self-fulfilling prophecies

A German horse named Clever Hans is widely known in the history of animal behavior as a classic example of unconscious bias leading to a false result.

Around the turn of the 20th century, Clever Hans was purported to be able to do math. For example, in response to his owner’s prompt “3 + 5,” Clever Hans would tap his hoof eight times. His owner would then reward him with his favorite vegetables. Initial observers reported that the horse’s abilities were legitimate and that his owner was not being deceptive.

However, careful analysis by a young scientist named Oskar Pfungst revealed that if the horse could not see his owner, he couldn’t answer correctly. So while Clever Hans was not good at math, he was incredibly good at observing his owner’s subtle and unconscious cues that gave the math answers away.

In the 1960s, researchers asked human study participants to code the learning ability of rats. Participants were told their rats had been artificially selected over many generations to be either “bright” or “dull” learners. Over several weeks, the participants ran their rats through eight different learning experiments.

In seven out of the eight experiments, the human participants ranked the “bright” rats as being better learners than the “dull” rats when, in reality, the researchers had randomly picked rats from their breeding colony. Bias led the human participants to see what they thought they should see.

Eliminating bias

Given the clear potential for human biases to skew scientific results, textbooks on animal behavior research methods from the 1980s onward have implored researchers to verify their work using at least one of two commonsense methods.

One is making sure the researcher observing the behavior does not know if the subject from one study group or the other. For example, a researcher would measure a cricket’s behavior without knowing if it came from the experimental or control group.

The other best practice is utilizing a second researcher, who has fresh eyes and no knowledge of the data, to observe the behavior and code the data. For example, while analyzing a file, I count chickadees taking seeds from a feeder 15 times. Later, a second independent observer counts the same number.

Yet these methods to minimize possible biases are often not employed by researchers in animal behavior, perhaps because these best practices take more time and effort.

In 2012, my colleagues and I reviewed nearly 1,000 articles published in five leading animal behavior journals between 1970 and 2010 to see how many reported these methods to minimize potential bias. Less than 10% did so. By contrast, the journal Infancy, which focuses on human infant behavior, was far more rigorous: Over 80% of its articles reported using methods to avoid bias.

It’s a problem not just confined to my field. A 2015 of published articles in the sciences found that blind protocols are uncommon. It also found that studies using blind methods detected smaller differences between the key groups being observed to studies that didn’t use blind methods, suggesting potential biases led to more notable results.

In the years after we published our article, it was cited regularly and we wondered if there had been any improvement in the field. So, we recently reviewed 40 articles from each of the same five journals for the year 2020.

We found the rate of papers that reported controlling for bias improved in all five journals, from under 10% in our 2012 article to just over 50% in our new review. These rates of reporting still lag behind the journal Infancy, however, which was 95% in 2020.

All in all, things are looking up, but the animal behavior field can still do better. Practically, with increasingly more portable and affordable audio and video recording technology, it’s getting easier to carry out methods that minimize potential biases. The more the field of animal behavior sticks with these best practices, the stronger the foundation of knowledge and public trust in this science will become.The Conversation

Todd M. Freeberg, Professor and Associate Head of Psychology, University of Tennessee

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Conversation

Tracking vampire worms with machine learning − using AI to diagnose schistosomiasis before the parasites causing it hatch in your blood

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theconversation.com – Trirupa Chakraborty, Ph.D. Candidate in Integrative Systems Biology, University of Pittsburgh – 2024-10-21 07:44:00

Trirupa Chakraborty, University of Pittsburgh; Aniruddh Sarkar, Georgia Institute of Technology, and Jishnu Das, University of Pittsburgh

Blood samples of infected with a parasitic worm that causes schistosomiasis contain hidden information that marks different stages of the disease. In our recently published research, our team used machine learning to uncover that hidden information and improve early detection and diagnosis of infection.

The parasite that causes schistosomiasis completes its cycle in two – first in snails and then in mammals such as people, dogs and mice. Freshwater worm eggs enter human hosts through the skin and circulate throughout the body, damaging multiple organs, the liver, intestine, bladder and urethra. When these larvae reach blood vessels connecting the intestines to the liver, they mature into adult worms. They then release eggs that are excreted when the infected person defecates, continuing the transmission cycle.

Since diagnosis currently relies on detecting eggs in feces, usually miss the early stages of infection. By the time eggs are detected, patients have already reached an advanced stage of the disease. Because diagnosis rates are poor, public health typically mass-administer the drug praziquantel to populations in affected regions. However, praziquantel cannot clear juvenile worms in early stages of infection, nor can it prevent reinfection.

Diagram of schistosomiasis infection cycle

Schistosomiasis isn’t usually diagnosed until the late stages of the disease.

DPDx/CDC

Our study provides a clear path forward to improving early detection and diagnosis by identifying the hidden information in blood that active, early stage infection.

Your body responds to a schistosomiasis infection by mounting an immune response involving several types of immune cells, as well as antibodies specifically targeting molecules secreted by or present on the worm and eggs. Our study introduces two ways to screen for certain characteristics of antibodies that signal early infection.

The first is an assay that captures a quantitative and qualitative profile of immune response, including various classes of antibodies and characteristics that dictate how they communicate with other immune cells. This us to identify specific facets of the immune response that distinguish uninfected patients from patients with early and late-stage disease.

Second, we developed a new machine learning approach that analyzes antibodies to identify latent characteristics of the immune response linked to disease stage and severity. We trained the model on immune profile data from infected and uninfected patients and tested the model on data that wasn’t used for and data from a different geographical location. We identified not only biomarkers for the disease but also the potential mechanism that underlies infection.

Why it matters

Schistosomiasis is a neglected tropical disease that affects over 200 million people worldwide, causing 280,000 deaths annually. Early diagnosis can improve treatment effectiveness and prevent severe disease.

In addition, unlike many machine learning methods that are black boxes, our approach is also interpretable. This means it can provide insights into why and how the disease develops beyond simply identifying markers of disease, guiding future strategies for early diagnosis and treatment.

Microscopy image of large white oval-shaped structures enclosing magenta oval-shaped structures, surrounded by smaller cells

Clusters of Schistosoma haematobium eggs surrounded by immune cells in bladder tissue.

CDC/Dr. Edwin P. Ewing Jr.

What still isn’t known

The schistosomiasis infection signatures we identified remain stable across two geographical regions across two continents. Future research could explore how well these biomarkers apply to additional populations.

Further, our work identifies a potential mechanism behind disease progression. We found that a particular immune response against a specific protein on the surface of the worm signals an intermediate stage of infection. Understanding how the immune system responds to this understudied antigen could improve diagnosis and treatment.

What’s next

Besides improving our understanding of how the immune system responds to different stages of infection, our findings identify key antigens that could pave the way for designing cost-effective and efficient approaches to diagnosis and treatments. Our next steps will include actually deploying these strategies in the field for early detection and management of disease.

The Research Brief is a short take about interesting academic work.The Conversation

Trirupa Chakraborty, Ph.D. Candidate in Integrative Systems Biology, University of Pittsburgh; Aniruddh Sarkar, Assistant Professor of Biomedical Engineering, Georgia Institute of Technology, and Jishnu DasUniversity of Pittsburgh

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The Conversation

More kids than ever need special education, but burnout has caused a teacher shortage

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theconversation.com – Kimber Wilkerson, Professor of Special Education, University of Wisconsin- – 2024-10-21 07:44:00

Many special education teachers quit after less than five years on the job.

10’000 Hours/Digital Vision via Getty Images

Kimber Wilkerson, University of Wisconsin-Madison

A growing number of students in public schools – right now, about 15% of them – are eligible for special education services. These services include specially designed instruction for students with autism, learning or physical disabilities, or traumatic brain injuries. But going into the current school year, more than half of U.S. public schools anticipate being short-staffed in special education. Dr. Kimber Wilkerson, a professor of special education and department chair at the University of Wisconsin-Madison, explains why there’s a shortage and what needs to be done to close the gap.

Dr. Kimber Wilkerson discusses the special education teacher shortage.

The Conversation has collaborated with SciLine to bring you highlights from the discussion, which have been edited for brevity and clarity.

Which students special education services?

Kimber Wilkerson: Students with a disability label receive special education services. They need these additional services and sometimes instruction in school so they can access the curriculum and thrive like their peers.

What is with staffing for special education?

Wilkerson: Since special education became a thing in the ’70s, there have always been challenges in filling all the special education positions.

In the past 10 years preceding the COVID-19 pandemic, those challenges started to increase. There were more open positions in special education at the beginning of each school year than in previous decades. In the 2023-24 school year, 42 states plus the District of Columbia reported teacher shortages in special education.

What is causing these shortages?

Wilkerson: One, there are fewer young people choosing teaching as a major in college and as a profession. And special education is affected by these lower rates more than other forms of education.

Also, there’s more attrition – people leaving their teaching job sooner than you might expect – not because they’re retiring, but because they are tired of the job.

They want to do something different. They want to go back to school. Sometimes it’s circumstances, but the number of people leaving the job before retirement age has increased. And in our , Wisconsin, about 35% of all educators leave the field before they hit their fifth year.

That number is even higher for special educators. About half of special educators are out of the profession within five years.

Why do special education teachers leave the profession?

Wilkerson: There’s not a national study that speaks to that reason. There are some localized studies, and people things like too much paperwork or too many administrative tasks associated with the job. Sometimes they report the students’ behavioral challenges. Sometimes it’s a feeling of isolation, or a lack of support from the school.

How are students with disabilities affected when their school does not have enough special educators?

Wilkerson: In a school that’s one special educator short, the other special educators have to take over that caseload. Instead of 12 students on their caseload, maybe now they have 20. So, the amount of individual attention given to each student with a disability decreases.

Also, when teachers with experience leave the profession, they leave behind a less experienced group of teachers. This means the students are losing out on the benefit of those years of wisdom and experience.

What are some strategies to recruit and retain more special education teachers?

Wilkerson: There’s a range of strategies that different universities, states and school districts have taken, like residency programs.

In these programs, the person who is learning to be a teacher, and who is referred to as a teaching resident, works alongside a mentor teacher for an entire year in a school, and they get paid to do so. They’re not the teacher of record, but they’re learning and getting paid, and they’re in that school community.

Can you tell us about your recent study on supporting new special education teachers?

Wilkerson: One thing that made a big difference is when the teachers in our study, which is now under review, had access to a mentor and a group of their peers. We called this facilitated peer-to-peer group of teachers a “community of practice.” Every other week, on Zoom, we’d get these new special education teachers from different school districts together, along with experienced teachers. And they would do some sort of work on problems, bringing in the things that were challenging, and work on possible solutions as a group.

We also used Zoom to do one-on-one mentoring. And what people liked about it was that they could to someone who wasn’t right in their building and right in their district who they could be open and vulnerable with.

Sometimes, special educators can be isolated because they’re not necessarily a part of a grade-level team. They work with kids across a lot of classrooms. This gave them an opportunity to have their own kind of community, and that made a difference.

We also surveyed their level of burnout and how good they felt about the job they did. And then we surveyed special education teachers who weren’t participating in our community of practice.

At the end of the year, those people who had that mentoring and the community of practice felt less burnt out, and they also felt more effective in the area of classroom management. And that’s critical, because burnout is one of the primary reasons people leave the profession.

So if we can make people feel like they’re better equipped to handle this challenging position, then that’s one strategy to increase the number of people wanting to stay in their job year after year.

Watch the full interview to hear more.

SciLine is a service based at the American Association for the Advancement of Science, a nonprofit that helps journalists include scientific evidence and experts in their news stories.The Conversation

Kimber Wilkerson, Professor of Special Education, University of Wisconsin-Madison

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The Conversation

Wild animals can experience trauma and adversity too − as ecologists, we came up with an index to track how it affects them

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theconversation.com – Xochitl Ortiz Ross, Ph.D. Candidate in Ecology & Evolutionary Biology, University of California, Los Angeles – 2024-10-21 07:44:00

Marmots were the perfect test species for a wildlife adversity index.

Xochitl Ortiz Ross

Xochitl Ortiz Ross, University of California, Los Angeles

Psychologists know that childhood trauma, or the experience of harmful or adverse events, can have lasting repercussions on the and well-being of people well into adulthood. But while the consequences of early adversity have been well researched in humans, people aren’t the only ones who can experience adversity.

If you have a rescue dog, you probably have witnessed how the abuse or neglect it may have experienced earlier in now influence its behavior – these pets tend to be more skittish or reactive. Wild animals also experience adversity. Although their negative experiences are easy to dismiss as part of life in the wild, they still have lifelong repercussions – just like traumatic events in people and pets.

As behavioral ecologists, we are interested in how adverse experiences early in life can affect animals’ behavior, the kinds of decisions they make and the way they interact with the world around them. In other words, we want to see how these experience affect the way they behave and survive in the wild.

Many studies in humans and other animals have shown the importance of early life experiences in shaping how individuals develop. But researchers know less about how multiple, different instances of adversity or stressors can accumulate within the body and what their overall impact is on an animal’s well-being.

Wild populations face many kinds of stressors. They compete for food, risk getting eaten by a predator, suffer illness and must contend with extreme weather conditions. And as if life in the wild wasn’t hard enough, humans are now adding additional stressors such as chemical, light and sound pollution, as well as habitat destruction.

Given the widespread loss of biodiversity, understanding how animals react to and are harmed by these stressors can conservation groups better protect them. But accounting for such a diversity of stressors is no easy feat. To address this need and demonstrate the cumulative impact of multiple stressors, our research team decided to develop an index for wild animals based on psychological research on human childhood trauma.

A cumulative adversity index

Developmental psychologists began to develop what psychologists now call the adverse childhood experiences score, which the amount of adversity a person experienced as a child. Briefly, this index adds up all the adverse events – including forms of neglect, abuse or other household dysfunction – an individual experienced during childhood into a single cumulative score.

This score can then be used to predict later-life health risks such as chronic health conditions, mental illness or even economic status. This approach has revolutionized many human health intervention programs by identifying at-risk children and adults, which allows for more targeted interventions and preventive efforts.

So, what about wild animals? Can we use a similar type of score or index to predict negative survival outcomes and identify at-risk individuals and populations?

These are the questions we were interested in answering in our latest research paper. We developed a framework on how to create a cumulative adversity index – similar to the adverse childhood experiences score, but for populations of wild animals. We then used this index to gain insights about the survival and longevity of yellow-bellied marmots. In other words, we wanted to see whether we could use this index to estimate how long a marmot would .

A marmot case study

Yellow-bellied marmots are a large ground squirrel closely related to groundhogs. Our research group has been studying these marmots in Colorado at the Rocky Mountain Biological Laboratory since 1962.

A marmot with a small device clipped to its ear, looking upwards.

A marmot wearing an ear tag.

Xochitl Ortiz Ross

Yellow-bellied marmots are an excellent study system because they are diurnal, or active during the day, and they have an address. They live in burrows scattered across a small, defined geographical area called a colony. The size of the colony and the number of individuals that reside within varies greatly from year to year, but they are normally composed of matrilines, which means related females tend to remain within the natal colony, while male relatives move away to find a new colony.

Yellow-bellied marmots hibernate for most of the year, but they become active between April and September. During this active period, we observe each colony daily and regularly trap each individual in the population – that’s over 200 unique individuals just in 2023. We then mark their backs with a distinct symbol and give them uniquely numbered ear tags so they can be later identified.

Although they can live up to 15 years, we have detailed information about the life experiences of individual marmots spanning almost 30 generations. They were the perfect test population for our cumulative adversity index.

Among the sources of adversity, we included ecological measures such as a late spring, a summer drought and high predator presence. We also included parental measures such as an underweight or stressed mother, being born or weaned late, and losing their mother. The model also included demographic measures such as being born in a large litter or having many male siblings.

Importantly, we looked only at females, since they are the ones who tend to stay home. Therefore, some of the adversities listed are only applicable to females. For example, females born in litters with many males become masculinized, likely from the high testosterone levels in the mother’s uterus. The females behave more like males, but this also reduces their life span and reproductive output. Therefore, having many male siblings is harmful to females, but maybe not to males.

A yellow-bellied marmot shown on a trail camera in Montana.

So, does our index, or the number of adverse events a marmot experienced early on, explain differences in marmot survival? We found that, yes, it does.

Experiencing even just one adversity before age 2 nearly halved an adult marmot’s odds of survival, regardless of the type of adversity they experienced. This is the first record of lasting negative consequences from losing a mother in this species.

So what?

Our study isn’t the only one of its kind. A few other studies have used an index similar to the human adverse childhood experiences score with wild primates and hyenas, with largely similar results. We are interested in broadening this framework so that other researchers can adopt it for the species they study.

A better understanding of how animals can or cannot cope with multiple sources of adversity can inform wildlife conservation and management practices. For example, an index like ours could help identify at-risk populations that require a more immediate conservation action.

Instead of tackling the one stressor that seems to have the greatest effect on a species, this approach could help managers consider how best to reduce the total number of stressors a species experiences.

For example, changing weather patterns driven by global heating trends may create new stressors that a wildlife can’t address. But it might be possible to reduce how many times these animals have to interact with people during key times of the year by closing trails, or providing extra food to replace the food they lose from harsh weather.

While this index is still in early , it could one day help researchers ask new questions about how animals adapt to stress in the wild.The Conversation

Xochitl Ortiz RossUniversity of California, Los Angeles

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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