Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Join the Spatial Ecology and Paleontology Lab each week for Fossil Fridays.
Become a fossil hunter and help discover how ecosystems have changed over time. Experience what it is like to be a paleontologist, finding and identifying new specimens.
Participants will sort through rock matrix collected from Natural Trap Cave in Wyoming to recover fossil specimens that are approximately 35,000 years old. These specimens support research projects examining how the community of species living around Natural Trap Cave has changed since the extinction of the cheetahs, lions, dire wolves, mammoths, camels, horses, and other megafauna that once lived in North America.
Drop in whenever it is convenient. No commitment is required. All are welcome, so bring your friends.
For more information, contact Katie Slenker at kslenker3@gatech.edu or visit mcguire.gatech.edu.
*Note: Data collected during Fossil Fridays may be included in research publications.
Event Details
Few neuroscientists would dispute that the brain relies on prediction. From houseflies evading swatters to humans catching baseballs, living things are constantly anticipating what comes next. Understanding how the brain generates those predictions could help explain one of neuroscience's most enduring questions: how the brain builds internal models of the world that allow us to learn, adapt, and anticipate what comes next.
“Without actively predicting the world, we cannot survive,” says Farzaneh Najafi, an assistant professor in the School of Biological Sciences and a faculty affiliate of Georgia Tech's Institute for Neuroscience, Neurotechnology, and Society. “There is quite some sensory-motor delay in the processing. We can’t just sit there, wait for the brain to process our environment, and then react.”
Part of the puzzle may lie in signals known as neural ramps. Almost like a drumroll leading up to a big reveal, neurons in some areas of the brain have shown gradual increases in activity immediately before a stimulus appears. For decades, researchers have interpreted this ramping activity as a neural signature of prediction, reflecting anticipation of an upcoming event.
Recently published in Science Advances, a new study from Najafi’s lab reveals these signals may not be “predictions” at all, but instead a way neurons track elapsed time.
“Surprisingly,” says Najafi, “the very first study from my lab called the Predictive Processing Lab showed that no, these are not prediction signals.”
The finding challenges a long-standing interpretation of one of neuroscience's most studied signals and reveals that the search for predictive neurons may lead to different circuits — or require different experiments to uncover.
The Problem With Prediction
There is a challenge in separating simple time tracking from active prediction. Just because numbers on a stopwatch are increasing doesn’t mean it’s counting up to a specific event.
To tease the problem apart, the team designed a series of experiments that progressively stripped prediction out of the equation.
Working with mice, the researchers presented audio and visual cues at carefully controlled intervals. Some appeared at regular, hence predictable, times, while others arrived unpredictably. If neurons are making predictions, their activity should look different when events are predictable versus when they are not.
But that’s not what they found. Even when the researchers introduced errors into those predictable patterns, activity remained largely the same.
“It was in the first year of collecting data in my newly established lab that my student, Yicong Huang, started showing me the data and I was shocked: how come we are not seeing a difference between the expected case and the unexpected case?” Najafi recalls. “Because the entire theory is that there is a difference.”
The team found even more definitive evidence by monitoring “naive” mice that had never seen the stimuli before. The brain must learn a pattern before it can anticipate it, yet they found that these neural ramps were present even in the first few trials.
Drumroll, Please
If these signals aren’t predictions, then what’s happening?
“What we are seeing are pure sensory signals,” she says. “They are not about predicting the timing of the upcoming stimulus. They're about encoding the time that is elapsed.”
Najafi thinks that what neuroscientists have long interpreted as an anticipatory “buildup” to a future event is actually a “relaxation” from the past. Rather than a drummer rolling up to a specific event, imagine one who is always rolling. Each stimulus briefly interrupts the performance before the rhythm gradually returns.
But they found that not every neuron behaves like a drummer. While “drummers” recover their interrupted rhythm after a stimulus, other neurons operate more like a reverberating gong, firing strongly after a stimulus before gradually quieting down.
“The beautiful part of this story is that neurons don't all do the same thing,” Najafi says. “One neuron ramps up quickly, another more slowly, another with a completely different time course. When you put that heterogeneous population together, you get a very robust readout of time.”
The finding may also have implications for how neuroscientists think the brain represents time itself.
“Our findings support the theory that time representation in the brain is an intrinsic property of neurons,” says Najafi. Because the signals appeared even in naïve mice and in sensory brain regions, the results suggest that timing may emerge from the properties of neurons themselves, rather than from a specialized timing system elsewhere in the brain.
For Najafi, the study doesn't close the case on predictive processing. Time, after all, is an important variable to track if you want to make predictions. Instead, it opens more questions about when and where those signals emerge.
“Maybe we didn't find them because this was a passive perception task, meaning mice just passively received stimuli without being instructed to attend to them. Maybe we need active perception or an active movement task, and that's when we can extract these predictive signals from the brain. Alternatively, we may need to search other brain areas to find neural signatures of temporal predictions.”
“Do I believe now that the brain is not doing predictive processing? Absolutely not,” Najafi says. “But before we say we've found evidence for a theory, we really need to do multiple carefully designed experiments. We need to attack this from many different angles.”
Funding: This research was supported by the Whitehall Foundation, the Research Corporation for Science Advancement, the Chan Zuckerberg Initiative, and the Georgia Institute of Technology.
DOI: 10.1126/sciadv.aed6417
The Georgia Institute of Technology's Institute for Neuroscience, Neurotechnology, and Society (INNS) has appointed Simon Sponberg as associate director for Interdisciplinary Research, where he will help foster collaborations, support emerging research initiatives, and advance interdisciplinary neuroscience research across campus.
Launched in 2025, INNS serves as a hub for neuroscience and neurotechnology research, connecting researchers across disciplines to advance discovery, innovation, and societal impact.
“A core part of INNS's mission is helping people find one another, connect around shared interests, and build something bigger than they could accomplish alone,” says Executive Director Christopher Rozell. “Simon has spent his career bringing together people, perspectives, and disciplines to tackle complex challenges. I can't think of a better person to help lead our interdisciplinary research efforts and support the next generation of collaborative neuroscience research.”
A longtime leader in Georgia Tech's neuroscience community, Sponberg helped shape the institute's early foundations through the Neuro Next Initiative, which evolved into INNS. As associate director, he will help guide research strategy, foster new collaborations, and support interdisciplinary work across the neuroscience ecosystem.
“Neuro-related research touches so many fields that we inevitably have a problem of finding all the potential right people and opportunities to tap into,” he said. “A core responsibility of this role is helping catalyze the ideas of new teams of talented researchers, educators, and trainees from inception to realization.”
Sponberg is the Glen Robinson Professor in Complex Systems with appointments in the School of Physics and the School of Biological Sciences, where he directs the Agile Systems Lab. His work also connects him to the Institute for Bioengineering and Bioscience (IBB) and the Institute for Robotics and Intelligent Machines (IRIM), underscoring the cross-disciplinary approach that defines both his research and leadership.
Since joining Georgia Tech in 2014, he has built a highly collaborative research program spanning neuroscience, biology, physics, engineering, and robotics while helping foster interdisciplinary connections across campus. He currently leads a Multidisciplinary University Research Initiative (MURI) that brings together neuroscientists and engineers from five universities to understand how brains achieve fast, flexible perception and decision-making in complex sensory environments. He also co-leads the Integrative Movement Sciences Institute, an NSF Biological Integration Institute focused on understanding movement and muscle function across scales.
His contributions have been recognized through numerous honors, including a Young Investigator Award from the International Society for Neuroethology, a Klingenstein-Simons Fellowship in the Neurosciences, and the Leddy Family Dean’s Faculty Excellence Award.
As associate director, Sponberg will focus on helping researchers identify new opportunities for connection and collaboration. In addition to overseeing seed funding programs, he hopes to create pathways for researchers to build teams, access support resources, pursue ambitious interdisciplinary research ideas, and team with Georgia Tech’s undergraduate and graduate neuroscience degree programs.
“I look forward to being a resource for our community when people are looking for help in building teams or finding opportunities to support their ideas,” he said. “Bring your best ideas and please reach out if you want to talk about ideas in the interdisciplinary neuro space that you want to see realized.”
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