Alina Studenova

Axon radius measured in vivo with diffusion MRI correlates with tissue microstructure based on histology in the human corpus callosum. There seems to be a coarse low-to-high anatomical pattern in corpus callosum that drives the correlation. It's more variable at the individual level. V.interesting!👍

Dipole fit to somatosensory evoked response. Not ideal at every time point, but around 50 ms lands in the somatosensory cortex, as expected.
#brainmovies

Stimulation of dopamine D1 receptors (and not D2) in anterior cingulate cortex (ACC) in mice influenced goal-directed behavior. Also, approach behavior was linked to a decrease of dopamine in ACC (less dopamine led to disinhibition of neurons). Cool!👏 Could it be related to EEG readiness potential?

Functionalism posits that consciousness is a function; the exact realising substrate doesn't matter. But realisers may matter. Ned Block points out that when we approach consciousness, we extrapolate from ourselves. It's easy when both function and realisers match ours and not when one is absent.💯

Alina Studenova - IQ-Mackintosh Some research topics are polarizing. It, of course, depends on the time and on the country. One prominent example is the topic of human intelligence. Intelligence research was and is socially and poli...

I'm a cognitive scientist, but my current research is about mechanisms of brain functioning. However, I really want to have a research project involving actual human behaviour. In preparation, I read a book. It's "IQ and Human Intelligence" by N. Mackintosh. www.alinastudenova.com/home/blog/bo...

But wait, some puzzling outcomes
Are really very nice!
It’s new exciting findings here,
And not just once but twice.
And as with all exciting things
New questions will arise.

Though modeling-obtained-effect
Elucidates misfit,
Of course, the question can be asked,
Whenever it’s legit?
It could be true, or somewhat true,
Or flawed, misleading shit.

The hidden states are out of sight,
Unreachable for eyes.
But I can model some of those,
of small and bigger size,
And see if modeling result
Can answer some of whys.

I checked the code, and checked again,
And found no mistakes.
Perhaps the data could be wrong?
But it was not the case.
And then I thought, “because it was
From different hidden states”.

#brainrhymes
The first analysis wrapped up,
It was an easy one.
The second followed after that,
And when this one was done,
It had appeared to be quite clear,
It’s different outcome.

Take a common pattern of functional connectivity in fMRI and remove it. What is left is the uniqueness of that participant. This paper suggests the "caricaturing" method—obtaining individual activations that are orthogonal to coactivations. Cool!💯 I agree. Individual differences deserve attention.

Expectations were explained by variance in deep cortical layers in primary auditory cortex and surrounding areas (7T fMRI). No laminar specificity for stimulus drive or repetition suppression. The authors interpret this in the context of predictive coding. Nice!👍 What does it mean for oscillations?

Now out in @ebiomedicine.bsky.social!

📖 Read the open-access article: authors.elsevier.com/sd/article/S...

#Neuroscience #Neurology #Parkinsonsdisease #Parkinsons #DeepBrainStimulation #DBS #Neurotechnology #Neuromodulation #Neurophysiology #BasalGanglia #OpenScience #Reproducibility

I'm not sure if I grasped what you said🙄. There is a spectrum of a "raw" signal and a spectrum of the envelope of a narrow-band filtered signal. Previous study used the former to claim that FC in EEG/MEG is mostly aperiodic (no peak, no oscillations). But you are talking about the latter, right?

There was a paper recently stating that functional connectivity in EEG/MEG is mostly aperiodic and not oscillatory. And I thought, what if it is oscillatory but from transients (that don't show clear peak in the spectrum)? This preprint suggests that it could be the case👏, at least for some tasks.

I use ICA for "source" extraction. For some participants, it works well, while for others, it miserably fails. Here, I tried to obtain the right and left M1/S1.
#brainmovies

Propagation of activity in LFP was termed "traveling waves" (TW)🙂‍↕️. But then people took this concept and began calling EEG phase lags TW🤨. This review delineated these two types, introducing first-order and second-order TW. Also, the authors review possible origins of two types (distinct origins!).👏

In this study, alpha power was found to be decreasing over the course of the experiment, while previous studies demonstrated an increase over time. The manuscript is scarce in the methods section, so it's hard to tell what exactly has been done. But if it is true, it requires explanation.🤔

Aging mice and humans with multiple sclerosis have the same failure in the oligodendrocyte differentiation program. This study identified a transcription factor cascade that fails to drive oligodendrocyte progenitor cells. Fascinating world of glia! Are white matter hyperintensities due to the same?

V. informative and practically useful piece! In fact, philosophy (epistemology) is factual field. The author lists 200 facts that he terms "epistemic preventable medicine"💯. Some facts are more obvious than others. My personal favorites are 38, 13-17, 165-168.
I wish the same for philosophy of mind.

Developmental steps are fascinating thing,
And learning all the terms is simpler than you think.
#brainrhymes

On mesencephalon, you got my point clear,
It's simply just midbrain, no more I can say here.

In diencephalon, divisions end on 'mus',
They're thala-, hypothala- and epithalamus.

Onto the telencephalon, it’s big, in fact, I pass.
Consists it of so many things, of laughs, and grit, and naps.

Take someone's rhombencephalon and split it into two halves,
Then met- and myelencephalon is what this person has.

The myelencephalon consists of just one lump,
medulla oblongata, it’s also known as bulb.

For metencephalon, its two constituents
Are pons and cerebellum, no more and yet, no less.

Imagine prosencephalon and split it in your head,
Then tele- and diencephalon are what remain instead.

If you take mesencephalon, not needed to divide.
It will remain midbrain until the day you die.

Between them mesencephalon, another greek nickname,
But mes- means in the middle, so call it just midbrain.

What I have just described was three-vesicle-stage,
One moves from three to five in second month of age.

On top was prosencephalon, the biggest it became.
If you're not fond of greek, then call it just forebrain.

The third was rhombencephalon, which looks like rhomb, hence name.
In simple English words, it's known as hindbrain.

Today, I introduce developmental rhyme,
What happens in the womb with brain parts over time?

Let’s first consider stage when brain looks like three balls,
That formed from neural tube, when neural plate was closed.

Objectively measured time can be very different from subjectively perceived time. However, Buzsáki argues that both time in physics and subjective time relate to motion (or speed, or change). He suggests that internal speed is attention.🙂‍↕️ This review also covers neuronal mechanisms of time-tracking.

Beta oscillations can be subdivided into low beta (13-20 Hz) and high beta (20-30 Hz). This paper nicely demonstrates dissociation using Hidden Markov Models. While low beta is completely suppressed during movement, high beta shows variability. Post-movement rebound is dominated by low beta. Cool!👍

Neurons x time points is higher-dimensional data. It can be reduced to a lower-dimensional manifold. This review gives an introduction, explanation, and summary of current evidence on neuronal manifolds. I appreciated the discussion of emergence: is the manifold more than the sum of its parts?