The fundamental research imperative.
Category: neuroscience – Page 146
Brain’s ‘blue spot’ key to healthy aging, early Alzheimer’s detection
In a demographically diverse sample of healthy people, Cornell researchers found dramatic changes over the human lifespan in the brain’s “blue spot”—a tiny region involved in cognition and believed to be the first affected by neurodegenerative conditions including Alzheimer’s disease.
Using specialized MRI scans to measure the intensity of neuromelanin, a pigment that gives the locus coeruleus (LC) its blue color, the research team observed an inverted U-shaped curve that peaked in later middle age before dropping off sharply, a finding that helps characterize healthy aging patterns.
Maintaining a stronger blue signal after age 60 was associated with better cognitive performance, according to the study involving 134 participants aged 19 to 86. Because of the participants’ diversity, including about 40% who were non-white, the researchers also discovered higher peaks among Black participants and women, groups known to be more susceptible to Alzheimer’s.
Nasal microbiome may help explain link between olfactory dysfunction and cognitive decline
As humans age, particularly after middle age, their brain functions, cognitive abilities and memory can deteriorate to varying degrees. Aging-related disorders marked by cognitive decline, particularly dementia, have become increasingly widespread over the past decades.
Estimates suggest that the number of individuals diagnosed with dementia could increase from 55 million in 2019 to around 139 million by 2050. Understanding the factors contributing to cognitive decline and devising methods to detect the first signs of dementia is thus of the utmost importance, as it could help to reliably pick up its emergence and plan therapeutic interventions accordingly.
In recent years, some studies have found a link between people’s ability to perceive and identify odors (i.e., olfactory function) and their cognitive abilities as older adults. While the relationship between olfactory dysfunction and cognitive decline is now well-documented, whether one causes the other or they are the result of similar aging-related or neurodegenerative mechanisms remains unclear.
Limitations of the use of the MP-RAGE to identify neural changes in the brain: recent cigarette smoking alters gray matter indices in the striatum
The magnetization-prepared rapid gradient-echo (MP-RAGE) T1-weighted high resolution structural MRI is a mainstay tool used to identify morphometric biomarkers of disease conditions, progression and treatment effects despite a critical limitation: the relaxation signal on which inferences are based is nearly indistinguishable for gray matter vs. blood flow (Lu et al., 2004; Wright et al., 2008). Thus, apparent reported morphometric findings might be at least partially related to transient changes in blood flow or other physiological signals.
Consistent with this technical limitation, using a standard analysis technique, voxel based morphometry (VBM), we recently reported that a single dose of a medication had “apparent” effects on T1-weighted MRIs (Franklin et al., 2013). Specifically, we observed medication-induced decreases in gray matter volume in the anterior cingulate and other regions that overlapped with changes in brain blood flow (perfusion). Similarly, others have shown effects of medication on T1-weighted scans that are likely transient. For example, acute levodopa administration altered gray matter indices on T1-weighted images in the midbrain (Salgado-Pineda et al., 2006). Further, in a well-controlled longitudinal VBM study of patients with attention deficit hyperactivity disorder (ADHD), Hoekzema et al.
Dismantled- Purity (Vocal Edit)
Dismantled’s “Purity” (Vocal Edit) off of their Dystopia CDM (2002)
Feedback surge.
Probe injected.
Data flood overloading neural circuitry.
Trodes on.
Pulse is racing.
Neon grid expanding into binary grey.
We trace our pathways, dissolve in beams.
We breach through cores on static wings.
Pressure starts.
Ice below you.
Shockwaves tumble, pulling.
down the consciousness.
below the circuits.
Noise sets in.
Nervous system failing.
Locked into eternity.
forever looped in frames.
We run through wires, disguise in screens.
We blend in patterns of input streams.
Aggregation — how the Wolfram model weaves the future — with Stephen Wolfram
In the previous excerpt from my conversation with Stephen Wolfram, I asked him how I can remain a single, coherent, persistent consciousness in a branching universe.
In this excerpt, we went deeper into this question. As a conscious observer, I have a single thread of experience. So if the universe branches into many timelines, why don’t I branch into many versions of me?
Stephen’s answer touched on many profound aspects of the Wolfram model.
He started with the failure of the Many Worlds interpretation of quantum mechanics to consider the possibility that different branches of history can merge, in other words, come back together again. This failure is rooted in assumption that the universe is continuous; as soon as we start thinking of the universe as discrete, such merging seems not only possible, but inevitable.
He went on to consider the concept of causal invariance, the idea that it doesn’t matter which of countless similar paths you take through the multiway graph, you end up in the same place. In the Ruliad, he said, causal invariance is inevitable.
Then we got to the core of the concept of the observer. According to Stephen Wolfram, an observer equivalences many different states and experiences the aggregate of these states.