PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Feedback activity in the visual cortex is necessary for the perception of objects

2021-06-30
(Press-News.org) An important function of our vision is to segregate relevant figures from the irrelevant background. When we look at a visual stimulus, it drives a cascade of neural activity from low-level to higher level visual brain areas. The higher areas also provide feedback to the lower areas, where figures elicit more activity than the background, as if figures in the brain are highlighted with extra activity. Researchers from the Netherlands Institute of Neuroscience (NIN) now showed that feedback causes the extra neuronal activity in low-level areas and that the extra activity is essential for figure-ground perception. The findings were published in Science Advances on the 30th June.

Silencing the brain with light to change perception

The primary visual cortex, also known as V1, is the first cortical brain area that receives visual information from the eyes and sends the information on to 'higher' brain areas for further processing. The research team, led by Pieter Roelfsema and Matthew Self, used optogenetics, a technique using light to silence nerve cells, in V1 in mice who had been trained to detect visual stimuli.

Disrupting the conversation between brain areas renders objects invisible

Critically, the researchers silenced only the late part of V1's response, allowing V1 to pass the visual information on to higher areas but preventing the feedback from higher areas back to V1. The result was dramatic and surprising: "When we allowed V1 to activate the higher areas, but curtailed feedback, mice only detected simple stimuli, but not stimuli on a complex background. This shows that feedback to V1 is necessary for figure-ground segregation" explained Lisa Kirchberger, the lead researcher on the project.

The researchers then silenced activity in the higher visual areas and found that it reduced the enhanced activity elicited by figures. "The results show that higher visual areas send information about objects back to V1 in the form of feedback. V1 and the higher areas are engaged in a conversation and if we disrupt the conversation by silencing V1 we can render objects invisible".

The paper represents a major step forward in our understanding of the role that feedback and sustained neural activity play in allowing us to see the world. Mice have very comparable visual systems to humans and it is likely that these results will help us to understand what happens when the visual system makes mistakes, such as in the hallucinations and visual distortions present in diseases such as schizophrenia.

INFORMATION:



ELSE PRESS RELEASES FROM THIS DATE:

Sweat-proof 'smart skin' takes reliable vitals, even during workouts and spicy meals

Sweat-proof smart skin takes reliable vitals, even during workouts and spicy meals
2021-06-30
MIT engineers and researchers in South Korea have developed a sweat-proof "electronic skin" -- a conformable, sensor-embedded sticky patch that monitors a person's health without malfunctioning or peeling away, even when a wearer is perspiring. The patch is patterned with artificial sweat ducts, similar to pores in human skin, that the researchers etched through the material's ultrathin layers. The pores perforate the patch in a kirigami-like pattern, similar to that of the Japanese paper-cutting art. The design ensures that sweat can escape through the patch, preventing skin irritation and damage to embedded sensors. The kirigami design also helps the patch conform to human skin as it stretches and bends. This flexibility, paired with ...

New microchip sensor measures stress hormones from drop of blood

New microchip sensor measures stress hormones from drop of blood
2021-06-30
New Brunswick, N.J. (June 30, 2021) - A Rutgers-led team of researchers has developed a microchip that can measure stress hormones in real time from a drop of blood. The study appears in the journal Science Advances. Cortisol and other stress hormones regulate many aspects of our physical and mental health, including sleep quality. High levels of cortisol can result in poor sleep, which increases stress that can contribute to panic attacks, heart attacks and other ailments. Currently, measuring cortisol takes costly and cumbersome laboratory setups, so the Rutgers-led team looked for a way to monitor its natural fluctuations in daily life and provide patients with feedback that allows them to receive the right treatment at the right ...

Computational analyses reveal 200 drugs that could be repurposed to treat COVID-19

2021-06-30
A new study based on computational analyses of how SARS-CoV-2 interacts with host cell proteins has identified 200 previously approved drugs that could be repurposed to treat COVID-19, 40 of which have already entered clinical trials. Furthermore, Namshik Han and colleagues identified 30 proteins induced by the SARS-CoV-2 virus that are targeted by 8 or more existing drugs, finding that nitric oxide production, which is important for viral synthesis, may be targeted by these drugs to fight infection. The researchers also identified 2 of these drugs with good safety profiles that successfully reduced viral replication in cellular assays, suggesting they could potentially prevent or treat COVID-19. Scientists now have sufficient ...

Where are the Foreigners of the First International Age?

Where are the Foreigners of the First International Age?
2021-06-30
The Bronze Age in the eastern Mediterranean has long been considered by researchers to have been the 'first international age,' especially the period from 1600-1200 BC, when powerful empires from Anatolia, Mesopotamia, and Egypt set up large networks of subordinate client kingdoms in the Near East. These empires fought, traded, and corresponded with one another, and ancient texts from the period reveal rich economic and social networks that enabled the movement of people and goods. A new study conducted by an interdisciplinary team of archaeologists, geneticists, and isotope experts, and published in PLOS ONE, investigated the movement of people in this period at a single regional center, a Bronze Age city-state called Alalakh in present-day southeastern Turkey. Their results indicate ...

COVID-19 bereavement care lacking for ethnic minorities

2021-06-30
University of Leeds news Embargo: Wednesday 30 June, 7pm GMT Bereavement care lacking for ethnic minorities Grieving friends and relatives from ethnic minority backgrounds are suffering from a lack of appropriate help to cope with the loss of a loved one, especially during the COVID-19 pandemic, researchers say. And the scarcity of data on the services that are available means providers do not know how support should be delivered to ensure they are suitable for different groups of people. The researchers, led by the University of Leeds and the University of Sheffield, reviewed evidence on UK bereavement care for ethnic minority ...

New research moves novel gene therapy for heart failure closer to the clinic

2021-06-30
Research at Baylor College of Medicine, the Texas Heart Institute and collaborating institutions is moving a novel promising gene therapy to treat heart failure closer to the clinic. Published in Science Translational Medicine, the study showed that knocking down the Hippo signaling pathway in cardiomyocytes in the hearts of pigs after they had a heart attack, resulted in heart tissue renewal and improved function when compared with pig hearts in which the Hippo signaling pathway was not modified. Given that the pig's heart is considered a valuable model to study the human heart, the findings suggest that this gene therapy may be useful in treating human heart failure. Heart failure remains the leading cause of mortality in the western ...

Thermal waves observed in semiconductor materials

Thermal waves observed in semiconductor materials
2021-06-30
A study published in Science Advances reports on the unexpected observation of thermal waves in germanium, a semiconductor material, for the first time. This phenomenon may allow a significant improvement in the performance of our electronic devices in a near future. The study is led by researchers from the Institute of Materials Science of Barcelona (ICMAB, CSIC) in collaboration with researchers from the Universitat Autònoma de Barcelona, and the University of Cagliari. Heat, as we know it, originates from the vibration of atoms, and transfers by diffusion at ambient temperatures. Unfortunately, ...

Scientists identify 160 new drugs that could be repurposed against COVID-19

2021-06-30
Cambridge scientists have identified 200 approved drugs predicted to work against COVID-19 - of which only 40 are currently being tested in COVID-19 clinical trials. In a study published today in Science Advances, a team led by researchers at the University of Cambridge's Milner Therapeutics Institute and Gurdon Institute used a combination of computational biology and machine learning to create a comprehensive map of proteins that are involved in SARS-CoV-2 infection - from proteins that help the virus break into the host cell to those generated as a consequence of infection. By examining this network using artificial intelligence (AI) approaches, ...

Monkeys also learn to communicate

2021-06-30
Language distinguishes us humans; we learn it through experience and social interactions. Especially in the first year of life, human vocalizations change dramatically, becoming more and more language-like. In our closest relatives, non-human primates, language development was previously thought to be largely predetermined and completed within the first few weeks after birth. In a behavioral study now published, researchers from the German Primate Center, the University of Tübingen and the Rockefeller University New York were able to show that the infantile development of vocalizations in common marmosets also includes an extended flexible phase, without ...

Autonomous excavators ready for around the clock real-world deployment

2021-06-30
Researchers from Baidu Research Robotics and Auto-Driving Lab (RAL) and the University of Maryland, College Park, have introduced an autonomous excavator system (AES) that can perform material loading tasks for a long duration without any human intervention while offering performance closely equivalent to that of an experienced human operator. AES is among the world's first uncrewed excavation systems to have been deployed in real-world scenarios and continuously operating for over 24 hours, bringing about industry-leading benefits in terms of enhanced safety and productivity. The researchers described their methodology in a research paper published ...

LAST 30 PRESS RELEASES:

A third of licensed GPs in England not working in NHS general practice

ChatGPT “thought on the fly” when put through Ancient Greek maths puzzle

Engineers uncover why tiny particles form clusters in turbulent air

GLP-1RA drugs dramatically reduce death and cardiovascular risk in psoriasis patients

Psoriasis linked to increased risk of vision-threatening eye disease, study finds

Reprogramming obesity: New drug from Italian biotech aims to treat the underlying causes of obesity

Type 2 diabetes may accelerate development of multiple chronic diseases, particularly in the early stages, UK Biobank study suggests

Resistance training may improve nerve health, slow aging process, study shows

Common and inexpensive medicine halves the risk of recurrence in patients with colorectal cancer

SwRI-built instruments to monitor, provide advanced warning of space weather events

Breakthrough advances sodium-based battery design

New targeted radiation therapy shows near-complete response in rare sarcoma patients

Does physical frailty contribute to dementia?

Soccer headers and brain health: Study finds changes within folds of the brain

Decoding plants’ language of light

UNC Greensboro study finds ticks carrying Lyme disease moving into western NC

New implant restores blood pressure balance after spinal cord injury

New York City's medical specialist advantage may be an illusion, new NYU Tandon research shows

Could a local anesthetic that doesn’t impair motor function be within reach?

1 in 8 Italian cetacean strandings show evidence of fishery interactions, with bottlenose and striped dolphins most commonly affected, according to analysis across four decades of data and more than 5

In the wild, chimpanzees likely ingest the equivalent of several alcoholic drinks every day

Warming of 2°C intensifies Arctic carbon sink but weakens Alpine sink, study finds

Bronze and Iron Age cultures in the Middle East were committed to wine production

Indian adolescents are mostly starting their periods at an earlier age than 25 years ago

Temporary medical centers in Gaza known as "Medical Points" (MPs) treat an average of 117 people daily with only about 7 staff per MP

Rates of alcohol-induced deaths among the general population nearly doubled from 1999 to 2024

PLOS One study: In adolescent lab animals exposed to cocaine, High-Intensity Interval Training boosts aversion to the drug

Scientists identify four ways our bodies respond to COVID-19 vaccines

Stronger together: A new fusion protein boosts cancer immunotherapy

Hidden brain waves as triggers for post-seizure wandering

[Press-News.org] Feedback activity in the visual cortex is necessary for the perception of objects