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Category: neuroscience – Page 2

Corollary Discharge Dysfunction to Inner Speech and its Relationship to Auditory Verbal Hallucinations in Patients with Schizophrenia Spectrum Disorders

Auditory-verbal hallucinations (AVH)—the experience of hearing voices in the absence of auditory stimulation—are a cardinal psychotic feature of schizophrenia-spectrum disorders. It has long been suggested that some AVH may reflect the misperception of inner speech as external voices due to a failure of corollary-discharge-related mechanisms. We aimed to test this hypothesis with an electrophysiological marker of inner speech.

Study Design.

Participants produced an inner syllable at a precisely specified time, when an audible syllable was concurrently presented. The inner syllable either matched or mismatched the content of the audible syllable. In the passive condition, participants did not produce an inner syllable. We compared the amplitude of the N1, P2, and P3-components of the auditory-evoked potential between: schizophrenia-spectrum patients with current AVH (SZAVH+, n = 55), schizophrenia-spectrum patients without current AVH (SZAVH−, n = 44), healthy controls (HC, n = 43).

Frontiers: Consciousness science: where are we, where are we going, and what if we get there?

The first distinction is between the notion of the level of consciousness and the notion of the contents of consciousness. In the first sense, consciousness is a property associated with an entire organism (a creature) or system: one is conscious (for example, when in a normal state of wakefulness) or not (for example, when in deep dreamless sleep or a coma). There is an ongoing vibrant debate about whether one should think of levels of consciousness as degrees of consciousness or whether they are best characterized in terms of an array of dimensions (11) or as “global states” (12). In the second sense, consciousness is always consciousness of something: our subjective experience is always “contentful”—it is always about something, a property philosophers call intentionality (3, 13). Here, again, there is some debate over the terms, for example, whether there can be fully contentless global states of consciousness (14) and whether consciousness levels (or global states) and contents are fully separable (11, 15).

The second distinction is between perceptual awareness and self-awareness (note that in this article, we use the terms consciousness and awareness interchangeably). Perceptual awareness simply refers to the fact that when we are perceptually aware, we have a qualitative experience of the external world and of our bodies within it (though of course, some perceptual experiences can be entirely fictive, such as when dreaming, vividly imagining, or hallucinating). Importantly, mere sensitivity to sensory information is not sufficient to be considered as perceptual awareness: the carnivorous plant Dionaea muscipula and the camera on your phone are both sensitive to their environment, but we have little reason to think that either has perceptual experiences. Thus, mere sensitivity is not sufficient for perceptual awareness, as it does not necessarily feel like something to be sensitive. This experiential character is precisely what makes the corresponding sensation a conscious sensation (16).

Scientists reverse Alzheimer’s in mice with groundbreaking nanotech

Researchers used supramolecular nanoparticles to repair the brain’s vascular system and reverse Alzheimer’s in mice. Instead of carrying drugs, the nanoparticles themselves triggered natural clearance of amyloid-β proteins. This restored blood-brain barrier function and reversed memory loss. The results point to a revolutionary new path for treating neurodegenerative diseases.

Detailed brain growth atlas in mice offers insights into brain development

Brain growth and maturation doesn’t progress in a linear, stepwise fashion. Instead, it’s a dynamic, choreographed sequence that shifts in response to genetics and external stimuli like sight and sound. This is the first high-resolution growth chart to explain changes of key brain cell types in the developing mouse brain, led by a team at Penn State College of Medicine and the Allen Institute for Brain Science.

Using advanced imaging techniques, the researchers constructed a series of 3D atlases that are like time-lapsed maps of the brain during its first two weeks after birth, offering an unparalleled look at a critical period of brain development. It’s a powerful tool to understand healthy brain development and neurodevelopmental disorders, the researchers explained.

The study, published in Nature Communications, also detailed how regions of the brain change in volume and explained the shift in density of key cell types within them.

Sensory expectations configure neural responses before disturbances occur, study reveals

A study led by Jonathan Michaels, a Faculty of Health professor at York’s School of Kinesiology and Health Science, reveals how the brains of humans and monkeys use sensory expectations to prepare for unexpected disturbances, enabling faster and more accurate motor responses.

Published today in Nature, the study demonstrates that motor circuits across the brain do not passively wait for sensory signals. Instead, they proactively anticipate potential challenges, configuring themselves to respond effectively to disturbances. The research represents a significant leap forward in uncovering the brain’s predictive capabilities and its role in .

This advancement provides a clearer picture of the neural mechanisms underlying movement preparation and response, illustrating how expectation itself enhances precision and stability. The discovery opens new pathways for improving rehabilitation techniques and advancing brain-computer interface technology.

Common genetic causes across motor neuron diseases identified

Motor neuron diseases, such as amyotrophic lateral sclerosis (ALS) and hereditary spastic paraplegia (HSP), share physical similarities but have been largely viewed as genetically distinct. However, an analysis led by investigators from St. Jude Children’s Research Hospital and the University of Miami Miller School of Medicine discovered that there are previously unknown ultrarare gene variants (genetic changes found in extremely few individuals) linked to the diseases, and significant overlap of contributing genes between the diseases among patients without family histories of a motor neuron disease.

This new appreciation of the shared genetic origins of different motor neuron diseases is critical to deciphering the origins of these disorders and ultimately developing meaningful therapeutics. The findings are published in Translational Neurodegeneration.

While both ALS and HSP cause progressive motor dysfunction, the two disorders also have distinct characteristics. Weakness in ALS may begin in the arms, legs, head or neck. HSP, by contrast, begins in the legs. The causative, or “canonical” genes for these diseases are also largely distinct.

Attentional failures after sleep deprivation are locked to joint neurovascular, pupil and cerebrospinal fluid flow dynamics

Yang et al. show that moments of failed attention we experience after sleep deprivation reflect brief ‘sleep-like’ episodes in the brain, corresponding to a brain-and body-wide event with altered brain activity, pupil size and brain fluid movement.

Bioinformatics uncovers regenerative therapy for spinal cord injury

Spinal cord injury (SCI) remains a major unmet medical challenge, often resulting in permanent paralysis and disability with no effective treatments. Now, researchers at University of California San Diego School of Medicine have harnessed bioinformatics to fast-track the discovery of a promising new drug for SCI. The results will also make it easier for researchers around the world to translate their discoveries into treatments. The findings are published in the journal Nature.

One of the reasons SCI results in permanent disability is that the neurons that form our brain and cannot effectively regenerate. Encouraging neurons to regenerate with drugs offers a promising possibility for treating these .

The researchers found that under specific experimental conditions, some mouse neurons activate a specific pattern of genes related to neuronal growth and regeneration. To translate this fundamental discovery into a treatment, the researchers used data-driven bioinformatics approaches to compare their pattern to a vast database of compounds, looking for drugs that could activate these same genes and trigger neurons to regenerate.

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