Modern phrenology

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For years, I've viewed functional neuroimaging (fMRI) studies as akin to modern phrenology. I've also noticed that the hype and frequency of 'sensational' findings from these studies seem to have diminished compared to 10 years ago.

After being inspired by Michael Nahm's 'insights' based on Adrian Owen's work with fMRI, I did some research and discovered an intriguing recent article on the topic:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6960120/

Here's a few interesting bits:

Quote:Consequently, since fMRI entered the scene in the early 1990s, it had seen an enthusiastic phase over the first two decades. However, after this period, neuroimaging—like almost any other psychological and medical sciences—was overrun by the replication crisis. Recent studies have estimated the reproducibility of psychological studies to be 39% or less and indicated a severe limitation of neuroimaging (fMRI) study reliability (5–9). Furthermore, the neurophysiological mechanisms behind the BOLD/fMRI signal are only partly understood, which makes it difficult to generalise results or to use it on an individual level for diagnostic purposes.

Quote:Jointly, psychology and neuroimaging suffer substantially from a lack of statistical power, meaning that the sample sizes are typically too small, and effect sizes are too low

Quote:One of the major knowledge gaps in the field is the assumption that the fMRI signal, i.e., the underlying BOLD effect (BOLD = blood oxygenation level dependent), is sufficiently reliable and stable, where “sufficiently” has never been defined yet. It is of crucial importance to keep in mind that the BOLD signal represents only an indirect measure of neuronal activity, through a cascade of physiological processes, called neurovascular coupling.

Quote:However, it is less studied, how susceptible the BOLD signal is to endogenous and exogenous influences and individual variability of the underlying mechanisms. Hence, it might occur that a change in the BOLD signal is detected while the true neuronal activity and connectivity remains unchanged. It is known that hormones (like cortisol), blood pressures, body mass index, time of the day (circadian rhythm), time of the year, sleep duration, and age influence blood volume, blood flow, and other vascular parameter, and hence the BOLD signal (19–23). Whether the individual variability of these parameters has a significant influence on the BOLD signal is largely unknown.

Quote:In other words, the BOLD signal is most likely not stable within and not necessarily comparable between subjects. These factors are just additional sources of variability of the fMRI signal that comes in addition to all other sources of noise that are affecting the measurement, like other environmental factors, thermal noise, noise of the measurement system itself, movements of the subjects, daylight length, temperature, and whether, to name a few, that may affect brain functions but also the stability of the MR system

I think the takeaway is that one needs to be very careful when drawing conclusions from fMRI.

The critical question is whether we will ever be able to develop noninvasive and safe tools for sampling neural activity that offer superior spatial and temporal resolution compared to current technologies. Without such advancements, I believe our understanding of the brain will remain limited.
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(2023-12-29, 11:58 AM)sbu Wrote: For years, I've viewed functional neuroimaging (fMRI) studies as akin to modern phrenology. I've also noticed that the hype and frequency of 'sensational' findings from these studies seem to have diminished compared to 10 years ago.

After being inspired by Michael Nahm's 'insights' based on Adrian Owen's work with fMRI, I did some research and discovered an intriguing recent article on the topic:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6960120/

Here's a few interesting bits:






I think the takeaway is that one needs to be very careful when drawing conclusions from fMRI.

The critical question is whether we will ever be able to develop noninvasive and safe tools for sampling neural activity that offer superior spatial and temporal resolution compared to current technologies. Without such advancements, I believe our understanding of the brain will remain limited.

It seems to me that the validity of Nahm's conclusions re. the value of the near-null fMRI BOLD measurements of the comatose Juan need to be specifically addressed, since I would think it should be valid to correlate near zero BOLD measurements to lack of activity in the key areas of the brain  thought to be associated with consciousness. In other words, can the various possible errors pointed out result in a high probability of false near null measurements of blood oxygenation in the relevant structures, when in reality these structures were busy processing neural data and burning up energy?

To invalidate Nahm's conclusions it would be necessary to specifically show that all the experimental work and practical clinical experience with using fMRI CORT measurements as indications of presence of consciousness or locked-in syndrome are invalid due to experimental errors arising from the basic technique. There could easily be endemic errors generated by the fMRI system when attempting to finely measure degree of ongoing blood oxygenation in certain structures, as opposed to just using it to indicate inactivity or activity (which was what it was being used for in the Owen study). It must be easier to accurately determine on/off state than to finely measure CORT levels in active neurological structures.
(This post was last modified: 2023-12-29, 04:12 PM by nbtruthman. Edited 1 time in total.)
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(2023-12-29, 11:58 AM)sbu Wrote: For years, I've viewed functional neuroimaging (fMRI) studies as akin to modern phrenology. I've also noticed that the hype and frequency of 'sensational' findings from these studies seem to have diminished compared to 10 years ago.

After being inspired by Michael Nahm's 'insights' based on Adrian Owen's work with fMRI, I did some research and discovered an intriguing recent article on the topic:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6960120/

Here's a few interesting bits:

I think the takeaway is that one needs to be very careful when drawing conclusions from fMRI.

The critical question is whether we will ever be able to develop noninvasive and safe tools for sampling neural activity that offer superior spatial and temporal resolution compared to current technologies. Without such advancements, I believe our understanding of the brain will remain limited.

Seems like the materialist faith is more hurt by this issue than parapsychology?
'Historically, we may regard materialism as a system of dogma set up to combat orthodox dogma...Accordingly we find that, as ancient orthodoxies disintegrate, materialism more and more gives way to scepticism.'

- Bertrand Russell


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(2023-12-29, 04:41 PM)Sciborg_S_Patel Wrote: Seems like the materialist faith is more hurt by this issue than parapsychology?

Metaphysically, it's neutral that we currently lack the means to fully understand the brain. This limitation doesn't inherently support or oppose materialism. Given the 39% reproducibility rate in fMRI studies, the reliability of 61% of these studies is questionable. This uncertainty probably includes research linking specific brain regions to particular mental states. Yet, materialism retains potential relevance as long as the comprehensive functions and purposes of the numerous neurons and synapses in the brain remain elusive.
(2023-12-29, 09:23 PM)sbu Wrote: Metaphysically, it's neutral that we currently lack the means to fully understand the brain. This limitation doesn't inherently support or oppose materialism. Given the 39% reproducibility rate in fMRI studies, the reliability of 61% of these studies is questionable. This uncertainty probably includes research linking specific brain regions to particular mental states. Yet, materialism retains potential relevance as long as the comprehensive functions and purposes of the numerous neurons and synapses in the brain remain elusive.

It just seems that more materialist theories depend on fMRI findings than non-materialist ones, especially since many sensational claims "proving" the mind is the brain rely on findings from scientific practices/methods that seem to become more rather than less questionable.
'Historically, we may regard materialism as a system of dogma set up to combat orthodox dogma...Accordingly we find that, as ancient orthodoxies disintegrate, materialism more and more gives way to scepticism.'

- Bertrand Russell


(2023-12-29, 09:23 PM)sbu Wrote: Metaphysically, it's neutral that we currently lack the means to fully understand the brain. This limitation doesn't inherently support or oppose materialism. Given the 39% reproducibility rate in fMRI studies, the reliability of 61% of these studies is questionable. This uncertainty probably includes research linking specific brain regions to particular mental states. Yet, materialism retains potential relevance as long as the comprehensive functions and purposes of the numerous neurons and synapses in the brain remain elusive.

But even fully understanding the brain in all its thousands of billions of neuron interactions would still not do it. Even such an understanding fundamentally couldn't really demonstrate anything else than correlation, not causation. This is also the case for all the other supposed materialist neuroscience apparent evidences for mind=brain, including fMRI studies. When materialist neuroscience solves the "hard problem", explaining how physical neurons and synapses and their interactions generate immaterial consciousness, and materialistically explains the CORT evidence and veridical NDEs, is when materialism wins. I'm not holding my breath.
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(2023-12-29, 09:40 PM)Sciborg_S_Patel Wrote: It just seems that more materialist theories depend on fMRI findings than non-materialist ones, especially since many sensational claims "proving" the mind is the brain rely on findings from scientific practices/methods that seem to become more rather than less questionable.

I agree that the outcomes of these studies are always interpreted in a way that supports a materialist view of reality. Though the scientific method is theoretically solid, and I often refer to its principles to challenge ideas I disagree with, the fact that it can take decades to expose significant flaws in a whole field highlights its practical limitations. The case of lobotomy, once considered sound science and rewarded with a Nobel Prize for its inventor, underscores this point.
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(2023-12-29, 09:40 PM)Sciborg_S_Patel Wrote: It just seems that more materialist theories depend on fMRI findings than non-materialist ones, especially since many sensational claims "proving" the mind is the brain rely on findings from scientific practices/methods that seem to become more rather than less questionable.
I think this is very important. Here is a rather old paper critiquing the state of FMRI some time ago:

https://journals.sagepub.com/doi/full/10...source=mfc

The interesting thing about it is that it demonstrates that the analysis of FMRI results was woefully careless back then. In other words the researchers wanted to use very dodgy data to try to prove all sorts of neurological ideas, when the data was too weak to justify what they were doing.

Obviously things may have improved, but the paper shows that neuroscience results are not always what they appear to be.

David
(This post was last modified: 2024-01-01, 12:32 AM by David001. Edited 1 time in total.)
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