Breaking News
December 13, 2018 - Paternal grandfather’s access to food associated with grandson’s mortality risk
December 13, 2018 - Our brain senses angry voices in a flash, study shows
December 13, 2018 - PM2.5 Exposure Linked to Asthma Rescue Medication Use
December 13, 2018 - Can’t exercise? A hot bath may help improve inflammation, metabolism, study suggests
December 13, 2018 - Can artificial intelligence help doctors with the human side of medicine?
December 13, 2018 - Virginia Tech and UC San Diego researchers team up to develop nonopioid drug for chronic pain
December 13, 2018 - NIH offers support for HIV care and prevention research in the southern United States
December 12, 2018 - Activating brain region could revive the urge to socialize among opioid addicts
December 12, 2018 - Relationship impairment appears to interfere with seeking mental health treatment in men
December 12, 2018 - Sleep, Don’t Cram, Before Finals for Better Grades
December 12, 2018 - Effective treatments for urticarial vasculitis
December 12, 2018 - Gun violence is a public health issue: One physician’s story
December 12, 2018 - The Science of Healthy Aging
December 12, 2018 - Yes to yoghurt and cheese: New improved Mediterranean diet
December 12, 2018 - Researchers uncover a number of previously unknown insecticide resistance mechanisms
December 12, 2018 - Regulating the immune system’s ‘regulator’
December 12, 2018 - In breaking bad news, the comfort of silence
December 12, 2018 - Study finds upward link between alcohol consumption and physical activity in college students
December 12, 2018 - FDA issues warning letter to Zhejiang Huahai Pharmaceutical involved in valsartan recall
December 12, 2018 - Presence of antiphospholipid antibodies tied to first-time MI
December 12, 2018 - DNA analysis finds that stethoscopes are teaming with bacteria
December 12, 2018 - New study could help inform research on preventing falls
December 12, 2018 - Women and men with heart attack symptoms receive different care from EMS
December 12, 2018 - Disrupted biological clock can contribute to onset of diseases, USC study shows
December 12, 2018 - New publications generate controversy over the value of reducing salt consumption in populations
December 12, 2018 - New data from TAILORx trial confirms lack of chemo benefit regardless of race or ethnicity
December 12, 2018 - Specific class of biomarkers can accurately indicate the severity of cancer
December 12, 2018 - Meds Taken Do Not Vary With ADL Impairment in Heart Failure
December 12, 2018 - Long-term study shows that HIV-2 is deadlier than previously thought
December 12, 2018 - People living near oil and gas wells show early signs of cardiovascular disease
December 12, 2018 - IONTAS founder and pioneer in phage display technology attends Nobel Prize Award Ceremony
December 12, 2018 - People who eat red meat have high levels of chemical associated with heart disease, study finds
December 12, 2018 - New method uses water molecules to unlock neurons’ secrets
December 12, 2018 - Genetics study offers hope for new acne treatment
December 12, 2018 - New computer model predicts prostate cancer progression
December 12, 2018 - Nobel Laureates lecture about immune checkpoint therapy for cancer treatment
December 12, 2018 - More Illnesses From Tainted Romaine Lettuce Reported
December 12, 2018 - Aspirin could reduce HIV infections in women
December 12, 2018 - The EORTC Brain Tumor Group and Protagen AG collaborate to study immuno-competence of long-term glioblastoma survivors
December 12, 2018 - Insights into magnetotactic bacteria could guide development of biological nanorobots
December 12, 2018 - Sacrificial immune cells alert body to infection
December 12, 2018 - Low-salt diet may be more beneficial for females than males
December 12, 2018 - Major soil organic matter compound battles chronic wasting disease
December 12, 2018 - Findings may open up new ways to treat dwarfism and other ER-stress-related conditions
December 12, 2018 - New computational model provides clearer picture of shape-changing cells’ structure and mechanics
December 12, 2018 - 10 Facts on Patient Safety
December 12, 2018 - Poorest dying nearly 10 years younger than the rich in ‘deeply worrying’ trend for UK
December 12, 2018 - Innovative care model for children with ASD reduces use of behavioral drugs in ED
December 12, 2018 - Spending time in and around Hong Kong’s waters linked to better health and wellbeing
December 12, 2018 - Simple measures to prevent weight gain over Christmas
December 12, 2018 - Research advances offer hope for patient-tailored AML treatment
December 12, 2018 - Researchers discover a ‘blind spot’ in atomic force microscopy
December 12, 2018 - Sprayable gel could help prevent recurrences of cancer after surgery
December 12, 2018 - SLU researchers explore how fetal exposure to inflammation can alter immunity in newborns
December 12, 2018 - How do patients want to discuss symptoms with clinicians?
December 12, 2018 - Zinc chelation may be able to deliver drug to insulin-producing cells
December 12, 2018 - Brigham researchers develop automated, low-cost tool to predict a woman’s ovulation
December 12, 2018 - Some people with Type 2 diabetes may be testing their blood sugar more often than needed
December 12, 2018 - Slow-growing type of glioma may be vulnerable to immunotherapy, suggests study
December 12, 2018 - Study provides new information regarding microRNA function in cellular homeostasis of zebrafish
December 12, 2018 - Study provides new understanding of mysterious ‘hereditary swelling’
December 12, 2018 - Researchers shed new light on how to combat Shiga and ricin toxins
December 12, 2018 - Pregnant Women Commonly Refuse Vaccines
December 12, 2018 - Drug treatment could offer new hope for some patients with brain bleeding
December 12, 2018 - Health care financial burden of animal-related injuries is growing, study says
December 12, 2018 - Macrophage cells could help repair the heart following a heart attack, study finds
December 12, 2018 - Researchers develop new system for efficiently producing human norovirus
December 12, 2018 - New artificial intelligence-based system to differentiate between different types of cancer cells
December 11, 2018 - Brazilian professors propose guidelines for therapeutic use of melatonin
December 11, 2018 - Healthy Lifestyle Lowers Odds of Breast Cancer’s Return
December 11, 2018 - New research identifies two genes linked to serious congenital heart condition
December 11, 2018 - NIH Director talks science, STEM careers with preteens
December 11, 2018 - Disabling a Cellular Antivirus System Could Improve Gene Therapy
December 11, 2018 - New tool swiftly provides accurate measure of patients’ cognitive difficulties
December 11, 2018 - NICE releases new guidelines for diagnosis and management of COPD
December 11, 2018 - Without Obamacare penalty, think it’ll be nice to drop your plan? Better think twice
December 11, 2018 - Researchers capture high-resolution X-ray and NMR image of key immune regulator
December 11, 2018 - Natural flavonoid is effective at treating leishmanisis infections, study shows
December 11, 2018 - Avoidant grievers unconsciously monitor and block mind-wandering contents, study shows
December 11, 2018 - Study identifies how hantaviruses infect lung cells
Neuroscientists identify circuit for brain’s statistical inference about motion

Neuroscientists identify circuit for brain’s statistical inference about motion

image_pdfDownload PDFimage_print

As the eye tracks a bird flying past, the muscles that pan the eyeballs to keep the target in focus set their pace not only on the speed they see, but also on a reasonable estimate of the speed they expect from having watched birds before.

A team of Duke University neuroscientists has found the neural wiring underlying this predictive behavior and watched in monkeys as the circuit is set to predict a given speed. They say the neurons of the brain’s sensory and motor systems are guided by a combination of past experience and sensory inputs.

When replicated in a neural network computer, these educated guesses made by motor neurons mimic Bayesian statistical inference, said Stephen Lisberger, the senior author on the paper and George Barth Geller Professor for Research in Neurobiology at Duke. Bayesian inference relies on the probability of a given outcome and updates it as more evidence becomes available.

The researchers built a mathematical model of the circuit that pitted prior experiences against a form of sensory input and adjusted the weight of its connections accordingly, just as the real life version does in its synapses.

“The model behaves just like the neurons,” Lisberger said. The team was able to render the neural responses as a series of equations that fit with Bayesian logic.

The work appears Sept. 17 in Nature Neuroscience.

“Motor control is guided by this reliability coded information,” Lisberger said. The memory of past experience is established by the strength of the synapses in the neural circuit that drives what are known as pursuit eye movements, and those synapses can be rapidly modified as experiences change. The heart of the system is an area of the brain that governs smooth eye movements in the frontal eye fields, FEFsem, for short.

Many papers in neuroscience over the last few years have showed the brain’s capacity to use inference and predictions based on past experience to temper its use of its sensory inputs. “To our knowledge this is the first time anyone has a found a place perfectly situated to cause the behavioral outputs we see,” said Lisberger, who is also a member of the Duke Institute for Brain Sciences.

The entire pursuit eye movement circuit, from the retina to the brain and back out to the eye muscles, is known to the researchers and they can measure any single neuron within it. They recorded the activity of single neurons as monkeys tracked moving targets and adapted their pursuit eye movements to changing speeds.

The team’s experiments also showed that when a visual target is made less visually distinct by lowering its contrast or brightness, the importance of estimates based on past experience becomes greater. “It’s like when you’re driving a familiar road at night or in the fog — you go by what you know is going to happen next as much as by what you can actually see,” Lisberger said.

“In low light, FEFsem says, ‘don’t track that,'” Lisberger said. “But if it’s a bright patch, it says ‘tune in, get it.'” This insight would enable them to predict eye movements by looking at just the neurons, he said.

Tagged with:

About author

Related Articles