Lifeboat Foundation

To make our way through the world, our brain must develop an intuitive understanding of the physical world around us, which we then use to interpret sensory information coming into the brain.

How does the brain develop that intuitive understanding? Many scientists believe that it may use a process similar to what’s known as “self-supervised learning.” This type of machine learning, originally developed as a way to create more efficient models for computer vision, allows computational models to learn about visual scenes based solely on the similarities and differences between them, with no labels or other information.

A pair of studies from researchers at the K. Lisa Yang Integrative Computational Neuroscience (ICoN) Center at MIT offers new evidence supporting this hypothesis. The researchers found that when they trained models known as neural networks using a particular type of self-supervised learning, the resulting models generated activity patterns very similar to those seen in the brains of animals that were performing the same tasks as the models.

A new study is finding that greener neighborhoods protect telomeres which prevent aging on a genetic level.

The role of telomeres in aging

Telomeres are repetitive sequences of DNA found at the ends of chromosomes that play a crucial role in preserving the integrity and stability of the genetic material within a cell.

Continue reading “Greener neighborhoods stop us from aging on a genetic level” »

To tackle the problem, the LIGO Scientific Collaboration followed an approach, proposed in 2001, that involves squeezing the noise ellipse differently at different frequencies. This frequency-dependent squeezing is realized by coupling the interferometer to a 300-m-long “filter” cavity. Through the cavity, the team could tailor the spectrum of the squeezed state, injecting amplitude squeezing in the low-frequency region and phase squeezing in the high-frequency region, says Victoria Xu, also of MIT LIGO Lab. “This [approach] allows us to reduce the limiting forms of quantum noise in each frequency band,” she says.

The frequency-dependent approach had previously been demonstrated in tabletop systems but implementing it to mitigate radiation-pressure noise in a full-scale gravitational-wave detector was a massive engineering challenge, Xu says. An important aspect was the minimization of optical losses due to imperfect optical components or to a mismatch of the light modes propagating in the various parts of the setup—the filter cavity, the squeezer, and the interferometer. “Any loss can be seen as a ‘port’ through which regular, nonsqueezed vacuum can enter,” Barsotti says.

The LIGO Scientific Collaboration tested frequency-dependent squeezing during the commissioning of the instrument upgrades for the fourth run, comparing detector noise spectra for no squeezing, frequency-independent squeezing, and frequency-dependent squeezing. Frequency-dependent squeezing yielded similar enhancements to frequency-independent squeezing at high frequencies while eliminating the degradation below 300 Hz due to radiation-pressure noise. The team estimated that the improved noise performance would increase the distance over which mergers can be detected by 15%–18%, corresponding to up to a 65% increase in the volume of the Universe that the LIGO interferometer will be able to probe. Quantum optics specialist Haixing Miao of Tsinghua University in China says this result demonstrates an exceptional ability to manipulate quantum states of light with optical cavities but also offers an impressive demonstration that quantum measurement theory applies to the kilometer scales of a gravitational-wave detector.

In an article for The Conversation, Distinguished Professor Emeritus of sociology Barry Markovsky looks at people’s belief in ghosts.

Is it possible for there to be ghosts? — Madelyn, age 11, Fort Lupton, Colorado

Certainly, lots of people believe in ghosts — a spirit left behind after someone who was alive has died.

Gaming is a $193 billion industry — nearly double the size of the film and music industries combined — and there are around three billion gamers worldwide. While online gaming can improve wellbeing and foster social relations, privacy and awareness issues could potentially offset these benefits and cause real harm to gamers.

The new study, by scientists at Aalto University’s Department of Computer Science, reveals potentially questionable data collection practices in online games, along with misconceptions and concerns about privacy among players. The study also offers risk mitigation strategies for players and design recommendations for game developers to improve privacy in online games.

‘We had two supporting lines of inquiry in this study: what players think about games, and what games are really up to with respect to privacy,’ says Janne Lindqvist, associate professor of computer science at Aalto. ‘It was really surprising to us how nuanced the considerations of gamers were. For example, participants said that, to protect their privacy, they would avoid using voice chat in games unless it was absolutely necessary. Our game analysis revealed that some games try to nudge people to reveal their online identities by offering things like virtual rewards.’

The incoherent component of the fluorescence from a single two-level atom is investigated after rejecting the coherent component. Contrary to intuition, its photon statistics experimentally shows strong photon bunching. This result suggests that the atom does in fact simultaneously scatter two photons.

Information about the internal properties of a system can only be obtained through interactions of the system with an external meter. However, such interactions generally result in entanglement between the system and the meter, making it difficult to trace the measurement result back to a specific value of the physical property in the system. It is therefore possible that the outcomes of quantum measurements depend in a nontrivial manner on the dynamics of the measurement interaction, possibly providing a physical explanation for the role of measurement contexts in quantum mechanics. Here we show that the effects of the measurement interaction on the meter can be described entirely in terms of the quantum coherent system dynamics associated with the back-action on the system.

Deep learning and predictive coding architectures commonly assume that inference in neural networks is hierarchical. However, largely neglected in deep learning and predictive coding architectures is the neurobiological evidence that all hierarchical cortical areas, higher or lower, project to and receive signals directly from subcortical areas. Given these neuroanatomical facts, today’s dominance of cortico-centric, hierarchical architectures in deep learning and predictive coding networks is highly questionable; such architectures are likely to be missing essential computational principles the brain uses. In this Perspective, we present the shallow brain hypothesis: hierarchical cortical… More.

Architectures in neural networks commonly assume that inference is hierarchical. In this Perspective, Suzuki et al. present the shallow brain hypothesis, a neural processing mechanism based on neuroanatomical and electrophysiological evidence that intertwines hierarchical cortical processing with a massively parallel process to which subcortical areas substantially contribute.

The goal of the order, according to the White House, is to improve “AI safety and security.” It also includes a requirement that developers share safety test results for new AI models with the US government if the tests show that the technology could pose a risk to national security. This is a surprising move that invokes the Defense Production Act, typically used during times of national emergency.

The executive order advances the voluntary requirements for AI policy that the White House set back in August, though it lacks specifics on how the rules will be enforced. Executive orders are also vulnerable to being overturned at any time by a future president, and they lack the legitimacy of congressional legislation on AI, which looks unlikely in the short term.

“The Congress is deeply polarized and even dysfunctional to the extent that it is very unlikely to produce any meaningful AI legislation in the near future,” says Anu Bradford, a law professor at Columbia University who specializes in digital regulation.