Lifeboat Foundation

This paper investigates the compatibility between the theoretical framework of the global neuronal workspace theory (GNWT) of conscious processing and the perturbational complexity index (PCI). Even if it has been introduced within the framework of a concurrent theory (i.e. Integrated Information Theory), PCI appears, in principle, compatible with the main tenet of GNWT, which is a conscious process that depends on a long-range connection between different cortical regions, more specifically on the amplification, global propagation, and integration of brain signals. Notwithstanding this basic compatibility, a number of limited compatibilities and apparent differences emerge. This paper starts from the description of brain complexity, a notion that is crucial for PCI, to then summary of the main features of PCI and the main tenets of GNWT. Against this background, the text explores the compatibility between PCI and GNWT. It concludes that GNWT and PCI are fundamentally compatible, even though there are some partial disagreements and some points to further examine.

Keywords: brain complexity; global neuronal worskpace theory; measurement of consciousness; perturbational complexity index; theory of consciousness.

© The Author(s) 2023. Published by Oxford University Press.

This study introduces a novel methodology for consciousness science. Consciousness as we understand it pretheoretically is inherently subjective, yet the data available to science are irreducibly intersubjective. This poses a unique challenge for attempts to investigate consciousness empirically. We meet this challenge by combining two insights. First, we emphasize the role that computational models play in integrating results relevant to consciousness from across the cognitive sciences. This move echoes Alan Newell’s call that the language and concepts of computer science serve as a lingua franca for integrative cognitive science. Second, our central contribution is a new method for validating computational models that treats them as providing negative data on consciousness: data about what consciousness is not. This method is designed to support a quantitative science of consciousness while avoiding metaphysical commitments. We discuss how this methodology applies to current and future research and address questions that others have raised.

Keywords: computationalism; consciousness; evidence; functionalism; methodology; modeling.

© The Author(s) 2021. Published by Oxford University Press.

Although the hippocampus is generally considered a cognitive center for spatial representation, learning, and memory, increasing evidence supports its roles in regulating locomotion. However, the neuronal mechanisms of the hippocampal regulation of locomotion and exploratory behavior remain unclear. In this study, we found that the inhibitory hippocampal synaptic projection to the medial septum (MS) bi-directionally controls the locomotor speed of mice. The activation of the MS-projecting interneurons in the hippocampus or the activation of the hippocampus-originated inhibitory synaptic terminals in the MS decreased locomotion and exploratory behavior. On the other hand, the inhibition of the hippocampus-originated inhibitory synaptic terminals in the MS increased locomotion. Unlike the septal projecting interneurons, the activation of the hippocampal interneurons projecting to the retrosplenial cortex did not change animal locomotion. Therefore, this study reveals a specific long-range inhibitory synaptic output from the hippocampus to the medial septum in the regulation of animal locomotion.

Keywords: GABAergic interneuron; exploratory behavior; hippocampus; inhibitory synapse; locomotion; septum.

Copyright © 2023 Chen, Arano, Guo, Saleem, Li and Xu.

Can one have a phenomenal experience to which one does not have access? That is, can you experience something without knowing? The dissociation between phenomenal ℗ and access (A) consciousness is widely debated. A major challenge to the supporters of this dissociation is the apparent inability to experimentally demonstrate that P-without-A consciousness exists; once participants report having a P-experience, they already have access to it. Thus, all previous empirical support for this dissociation is indirect. Here, using a novel paradigm, we create a situation where participants (Experiment 1, N = 40) lack online access to the stimulus yet are nevertheless able to retrospectively form judgements on its phenomenal, qualitative aspects. We further show that their performance cannot be fully explained by unconscious processing or by a response to stimulus offset (Experiment 2, N = 40). This suggests that P and A consciousness are not only conceptually distinct, but might also be teased apart empirically. STATEMENT OF RELEVANCE: A critical question in the scientific quest towards solving the problem of consciousness focuses on the ability to isolate conscious experiences at their purity, without any accompanying cognitive processes. This challenge has been augmented by a highly influential — yet controversial — dissociation suggested by the philosopher Ned Block between Phenomenal consciousness, or the “what it is like” to have an experience, and Access consciousness, indexing the ability to report that one has that experience. Critically, these two types of consciousness most typically go together, making it highly difficult — if not impossible — to isolate Phenomenal consciousness. Our work shows that the dissociation between phenomenal and access consciousness is not merely conceptual, but can also be empirically demonstrated. It further opens the gate to future studies pinpointing the neural correlates of the two types of consciousness.

Keywords: Access consciousness; Cognition; Consciousness; Phenomenal consciousness; Qualia; Unconscious processing.

Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.

In pre-clinical trials, a small molecule effectively regrew neurons, reduced inflammation, and improved memory, speed, coordination, grip strength, and more. The finding could have a profound impact on aging and the diseases that accompany it.

In conducting the research, scientists at the University of Texas MD Anderson Cancer Center, turned their focus to telomerase reverse transcriptase (TERT), an enzyme that is known to help synthesize and extend telomeres, the protective caps at the ends of chromosomes that help cells divide. TERT levels are reduced as we age.

Without sufficient levels of TERT, when our telomeres shrink or get seriously modified, they can lead to a process that continually damages our DNA, which causes cells to release inflammatory compounds that can in turn lead to aging, tissue damage, and cancer.

A new technique combining magnetic resonance imaging and x-ray fluorescence can characterize, with single-neuron resolution, the presence of toxic forms of iron that might be associated with neurodegenerative diseases.

Iron plays a major role in life. Most obviously, it keeps us alive, helping to ferry oxygen around our bloodstreams. It is also essential in cellular energy production, in the immune-system response, and in brain function—where it helps catalyze the synthesis of dopamine and other neurotransmitters. Iron can, however, be a double-edged sword. An iron excess has been implicated in many ailments, including neurodegenerative conditions such as Alzheimer’s, multiple sclerosis, and Parkinson’s disease—where dopaminergic neurons (neurons that use iron to synthesize dopamine) degenerate. It is thought that the toxicity of iron depends on how it is stored: iron firmly bound within proteins such as ferritin may be less toxic than iron more loosely bound to low-affinity sites, where it is more able to participate in reactions that generate cell-damaging hydroxyl radicals [1].

As lasers go, those made of Titanium-sapphire (Ti: sapphire) are considered to have “unmatched” performance. They are indispensable in many fields, including cutting-edge quantum optics, spectroscopy, and neuroscience. But that performance comes at a steep price. Ti: sapphire lasers are big, on the order of cubic feet in volume. They are expensive, costing hundreds of thousands of dollars each. And they require other high-powered lasers, themselves costing $30,000 each, to supply them with enough energy to function.

As a result, Ti:sapphire lasers have never achieved the broad, real-world adoption they deserve—until now. In a dramatic leap forward in scale, efficiency, and cost, researchers at Stanford University have built a Ti: sapphire laser on a chip. The prototype is four orders of magnitude smaller (10,000x) and three orders less expensive (1,000x) than any Ti: sapphire laser ever produced.

“This is a complete departure from the old model,” said Jelena Vučković, the Jensen Huang Professor in Global Leadership, a professor of electrical engineering, and senior author of the paper introducing the chip-scale Ti: sapphire laser published in the journal Nature.

Research teams have successfully regenerated mouse brain circuits using rat stem cells, showcasing a new method for restoring brain function and studying interspecies brain development.

These findings open up possibilities for treating neurological diseases and understanding brain evolution, while also hinting at future clinical applications and ethical challenges in using similar techniques for human organ transplantation.

Scientists regenerate neural pathways in mice with cells from rats.

Hacking my brain implant wouldn’t do much, he asserted, adding, “You might be able to see like some of the brain signals. You might be able to see some of the data that Neuralink’s collecting.”

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Norland Arbaugh did not specify the data that is being collected by Neuralink chip which is almost the size of a coin and contains thousands of electrodes that monitor and stimulate brain activity, as per the company. This information is digitally transmitted to researchers.