Cerebrum

Perpetuating the meme that rodent PTSD experiments necessarily apply to humans

gettingwell4 0-1 star Wasted resources, Cerebrum, Limbic system, Lower brain, Memory, Neurochemicals, Stress

This 2015 Texas A&M rodent study found:

“Propranolol administration dampened the stress-induced impairment in extinction observed when extinction training is delivered shortly after fear conditioning.”

The researchers were way off base in extrapolating this study to humans:

“Propranolol may be a helpful adjunct to behavioral therapy for PTSD, particularly in patients who have recently experienced trauma.”

Would National Institutes of Health Grant R01MH065961 money have been available without perpetuating the meme that rodent PTSD experiments necessarily apply to humans? Or are a priori findings necessary in order to get research funded?

In rodent studies such as this one, the origins of both the disease and the “cure” are all exerted externally. But humans aren’t lab rats. We can perform effective therapy that doesn’t involve some outside action being done to us.

Studies such as Fear extinction is the learned inhibition of retrieval of previously acquired responses make clear that extinction is equivalent to suppression. “Behavioral therapy for PTSD” that suppresses symptoms can’t be a “cure” for humans since the original causes for the symptoms aren’t treated.

Even if this study’s recommendation to administer a drug applied to humans, neither drugs nor “behavioral therapy for PTSD” address the underlying causes.

http://www.pnas.org/content/112/28/E3729.full “Noradrenergic blockade stabilizes prefrontal activity and enables fear extinction under stress”

What’s an appropriate control group for a schizophrenia study?

gettingwell4 < 0 Detracted from science, Cerebrum ,

The researchers who did Our long-term memory usually selects what we pay closer visual attention to study were back zapping subjects’ brains again in this 2015 human study.

Prior to zapping subjects’ brains:

“In healthy individuals, these theta waves were steady and synchronized, but in people with schizophrenia, the waves were weak and disorganized, suggesting that they were having a harder time processing the mistake. And the subjects’ behavior bore that out—the healthy subjects slowed down by a few milliseconds when they made mistakes and did better in the next round, while the subjects with schizophrenia did not.”

Processing of an appropriate control group wasn’t clear to me from reading supplementary material. Subject patients were diagnosed with schizophrenia and took psychoactive medication which these researchers equated to chlorpromazine (Thorazine) dosages. Control group subjects had neither the condition nor were prescribed medications.

  • How did these researchers differentiate influences of psychoactive medications on experimental results from other influences on subjects’ conditions?
  • Were there numerical calculations not shown in supplementary material that somehow nullified effects of psychoactive medications?
  • To be sure that zapping was effective for subjects’ conditions, wouldn’t control group subjects need to take the same medications so that experimental data reflected only differences attributable to schizophrenia?

These researchers also asserted:

“Causal changes in the low-frequency oscillations improved behavioral responses to errors and long-range connectivity at the single-trial level.”

However, brain waves can’t be termed as base causes of human behavior. Studies such as:

clearly established that brain waves are effects of base causes.

http://www.pnas.org/content/112/30/9448.full “Synchronizing theta oscillations with direct-current stimulation strengthens adaptive control in the human brain”

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Interruptions to the circadian cycle negatively affect memory consolidation

gettingwell4 2-3 stars Required further work, Anterior cingulate cortex, Cerebrum, Hippocampus, Limbic system, Memory, Stress

This 2015 German rodent study found:

“The control of sleep and memory consolidation may share common molecular mechanisms.”

Somewhat counter to the “Enhanced memory consolidation” in the study’s title, the researchers also found:

“Elevated IGF2 [insulin-related growth factor 2] signaling in the long term, however, has a negative impact on cognitive processing.”

The IGF2 finding was in genetically altered mice that had their circadian rhythm permanently disturbed, however. The study didn’t clearly determine the contribution of other factors that could have contributed to the cognitive decline.

The study traced fear memories induced by stress through the cerebrum to the anterior cingulate cortex and hippocampus parts of the limbic system.

Researchers have no problems studying emotional memories in these brain areas with rodents. In human memory experiments, however, emotional content is consistently excluded, as if none of our memories had anything to do with our feelings.

http://www.pnas.org/content/112/27/E3582.full “Enhanced memory consolidation in mice lacking the circadian modulators Sharp1 and -2 caused by elevated Igf2 signaling in the cortex”

A study on alpha brain waves and visual processing that had limited findings

gettingwell4 0-1 star Wasted resources, Amygdala, Beliefs, Cerebrum, Hippocampus, Limbic system, Memory

This 2015 Wisconsin human study found:

“Forming predictions about when a stimulus will appear can bias the phase of ongoing alpha-band oscillations toward an optimal phase for visual processing, and may thus serve as a mechanism for the top-down control of visual processing guided by temporal predictions.”

The researchers measured delta (1-4 Hz), theta (4-7 Hz), alpha (9-13 Hz), and low beta (15-20 Hz) brain waves. Their findings applied only to the alpha band in their experimental tasks, which excluded emotional content.

Brain waves studies such as Are hippocampal place cells controlled by theta brain waves from grid cells? and Research that identifies the source of generating gamma brain waves established different experimental conditions that elicited brain waves in non-alpha frequency bands. Such studies may have been relevant to further explain this study’s negative findings.

Visual perception studies such as We are attuned to perceive what our brains predict will be rewarding and Our long-term memory usually selects what we pay closer visual attention to provided insight into possible causes for the observed effects. It may have provided additional findings if the researchers of this study were also interested in causal factors that affected visual processing.

Other studies on visual perception such as The amygdala is where we integrate our perception of human facial emotion provided reasons to not exclude emotional content in brain studies. The current study’s researchers claimed that they provided insights relevant to neurological disorders by stating:

“Because forming the appropriate sensory predictions can have a large impact on our visual experiences and visually guided behaviors, a mechanism thought to be disrupted in certain neurological conditions like autism and schizophrenia, an understanding of the neural basis of these predictions is critical.”

However, I didn’t see that the researchers provided such an understanding since their experimental designs excluded emotional content. I wonder what the reviewer saw that justified this Significance section statement.

http://www.pnas.org/content/112/27/8439.full “Top-down control of the phase of alpha-band oscillations as a mechanism for temporal prediction”

Do scientists have to perpetuate memes in order to keep their jobs?

gettingwell4 < 0 Detracted from science, Amygdala, Anterior cingulate cortex, Beliefs, Cerebrum, Hippocampus, Limbic system, Thalamus , , ,

I was disgusted by this 2015 Korean human study.

Is the current state of science such that researchers won’t be funded unless there’s an implicit guarantee that their studies will produce politically correct findings? It seemed that the primary reason for the study’s main finding of:

“Neural markers reflecting individual differences in human prosociality”

was to perpetuate that non-causal, non-explanatory meme.

Per If research treats “Preexisting individual differences” as a black box, how can it find causes for stress and depression? it wasn’t sufficient in 2015 to pretend that there are no early-life causes for the observed behavior and fMRI scan results of the subjects. Such a pretense leads to the follow-on pretense that later-life consequences are not effects, but are instead, a “mystery” due to “individual differences.”

The researchers asserted:

“Our present findings shed some light on the mystery of human altruism.”

Weren’t the findings of the People who donated a kidney to a stranger have a larger amygdala 2014 study of extraordinary altruists big enough clues for these researchers to feature the amygdala in the fMRI scans?

The main experiment had the female, college student, right-handed subjects try to “reduce the duration of exposure to stressful noise.” Why weren’t brain areas that are especially susceptible to stress like the hippocampus featured in the fMRI scans?

The secondary reason for the study seemed to be to perpetuate the harmful “self-sacrifice = good, individuality = bad” meme.

The main reason this meme is harmful is that it condones a subset of people’s unconscious act outs. People are encouraged to avoid conscious awareness both of who they really are and of what drives their feelings, thoughts, and actions.

Despite not asking the subjects directly about either their motivations or their histories, these researchers asserted that the study demonstrated:

“The automatic and intuitive nature of prosocial motivation.”

What was largely observed were the subjects’ unconscious act outs, not some higher-order functions as the researchers mischaracterized them.

Similar to Who benefits when research promotes a meme of self-sacrifice? I suspect that a major motivation behind scientific justification for memes like the self-sacrifice promoted by this study is to rush people past what really happened in their lives.

I wonder what value we would place on the “social norms internalized within an individual” if we felt and honestly understood our real history.

This study and the Do you know a stranger’s emotional motivations for smiling? study had the same reviewer, and shared several of the burden-of-proof problems. Both studies demonstrated a lack of researcher interest in finding causes for the observed effects.

What was the agenda with these researchers and the reviewer? Why would the researchers glorify factors that cause difficulties when one tries to live a life of one’s own choosing?

http://www.pnas.org/content/112/25/7851.full “Spatial gradient in value representation along the medial prefrontal cortex reflects individual differences in prosociality”

Dopamine may account for differences in cognitive performance

gettingwell4 2-3 stars Required further work, Anterior cingulate cortex, Cerebrum, Dopamine, Hippocampus, Limbic system, Memory, Neurochemicals, Thalamus ,

This 2015 German human study found:

“Dopamine may account for adult age differences in brain signal variability.”

The researchers administered amphetamine to the subjects to boost their dopamine levels, and measured their cognitive performance on several working memory tests under fMRI:

“Older adults expressed lower brain signal variability at placebo, but met or exceeded young adult..”

brain signal variability levels when on speed.

The order of the tests also influenced the results. Older adults who received amphetamine during the initial series of tests performed better on placebo during the second series of tests.

As is often done, the researchers focused on effects and not causes. I didn’t see questionnaires or investigation into possible historical or biological factors for reduced dopamine levels, leaving the researchers with age as the only correlated-but-not-causative explanation.

http://www.pnas.org/content/112/24/7593.full “Amphetamine modulates brain signal variability and working memory in younger and older adults”

Unconscious stimuli have a pervasive effect on our brain function and behavior

gettingwell4 5+ stars Premium, Brain development, Cerebrum, Epigenetics, Limbic system, Lower brain, Memory, Primal Therapy , , , , ,

This 2015 Swedish human study, performed at the institution that awards the Nobel Prize in Physiology or Medicine, found:

“Pain responses can be shaped by learning that takes place outside conscious awareness.”

Images of neutral male faces were used as conditioning stimuli which the subjects were trained to associate with levels of pain.

The concluding sentence of the study:

“Our results demonstrate that conscious awareness of conditioned stimuli is not required during either acquisition or activation of conditioned analgesic and hyperalgesic responses, and that low levels of the brain’s hierarchical organization are susceptible for learning that affects higher-order cognitive processes.”

From the study’s abstract:

“Our results support the notion that nonconscious stimuli have a pervasive effect on human brain function and behavior and may affect learning of complex cognitive processes such as psychologically mediated analgesic and hyperalgesic responses.”

Principles of Dr. Arthur Janov’s Primal Therapy related to this study’s findings are:

  • Experiences associated with pain can be remembered below our conscious awareness.
  • Unconscious memories associated with pain, when activated, have varying forms of expression as they pass up through our levels of consciousness.
  • These memories, when activated, have effects on our feelings, thinking, health, brain functioning, and behavior that are usually below our conscious awareness.

I’ll use one of Dr. Janov’s 2011 blog posts, On Being Alone, to show an example of how the study’s findings of:

  • “Conscious awareness of conditioned stimuli is not required during either acquisition or activation of conditioned..responses” and
  • “Nonconscious stimuli have a pervasive effect on human brain function and behavior”

are seen through the lens of Primal Therapy:

Unconscious memories associated with the pain of being left alone may be stored, especially in the developing brain, in our lower brain areas below conscious awareness: “Pain of being left alone a lot in childhood and infancy, added to the ultimate aloneness right after birth when no one was there for the newborn. That imprints a primal terror where a naïve, innocent and vulnerable baby has no one to lean on, to be held by, to snuggle up to, to be comforted. To be loved.”
As we develop, the cumulative memories associated with the pain of being left alone, when activated, may affect our feelings, thoughts, and behavior: “And that also has multiple meanings: no one wants me; there is no one there for me: no one wants to be with me; I have no love and no one who cares. One races to phone others so as not to feel alone. One runs from the feeling and struggles mightily not to be alone. Or, depending on earlier events one stays alone out of that same feeling. These are by and large the depressives.”
Although memories associated with the pain of being left alone may be formed in our early lives, they remain decades later, and can be activated below our conscious awareness: “When something in the present occurs which is similar to an old feeling “I am all alone and no one wants me,” the old feelings are triggered off..and the whole feeling rises toward conscious/awareness where it must be combated. Either the person wallows in the feeling and is overwhelmed by it even when she doesn’t even know what “it” is. Or the compounded feeling drives the act-out, forcing the person into some kind of social contact.”

A PNAS commentary on the study stated:

“Pain, analgesia, and hyperalgesia represent higher-order cognitive functions.”

and attempted to draw conclusions from this reasoning.

The commentator was incorrect regarding pain. I didn’t see where this study showed or even postulated that pain was always a higher-order cognitive function. In fact, the researchers cited a sea slug study and stated:

“It would not be surprising if vestiges of simpler nonconscious processes would also be operative under some conditions.”

Maybe it would have provided clarifications if the researchers specifically defined “low” and “higher” used throughout the study in statements such as the closing sentence:

“Low levels of the brain’s hierarchical organization are susceptible for learning that affects higher-order cognitive processes.”

http://www.pnas.org/content/112/25/7863.full “Classical conditioning of analgesic and hyperalgesic pain responses without conscious awareness”

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The effects of inescapable, uncontrollable, repeated stress on the hippocampus

gettingwell4 4-5 stars Advanced knowledge, Amygdala, Cerebrum, Cortisol, Epigenetics, Glutamate, Hippocampus, Limbic system, Neurochemicals, Stress , , ,

This 2015 MIT rodent study found:

“Behavioral stress impairs cognitive function via activation of a specific direct neural circuit from the basolateral amygdala to the dorsal hippocampus. Moreover, we delineate a molecular mechanism by which behavioral stress is translated to hippocampal dysfunction via a p25/Cdk5 (cyclin-dependent kinase 5)-dependent pathway and epigenetic alterations of neuroplasticity-related gene expression.”

The researchers made several intermediate findings to develop their main finding:

1. “Repeated stress is accompanied by

  • generation of p25,
  • up-regulation and phosphorylation of glucocorticoid receptors,
  • increased HDAC2 [the gene encoding the histone deacetylase 2 enzyme] expression, and
  • reduced expression of memory-related genes [most, but not all that were tested] in the hippocampus.”

2. “BLA [basolateral amygdala] activation is both necessary and sufficient for stress-associated molecular changes and memory impairments.”

3. “This effect [2. above] relies on direct glutamatergic projections from the BLA to the dorsal hippocampus.”

4. “p25 generation is necessary for the stress-induced memory dysfunction.”

From the Results section:

“Control mice showed a significant preference for the novel over the familiar object or location, whereas RFS [repetitive foot shock]-treated mice performed no better than chance.”

The subject adult mice underwent:

“Inescapable, uncontrollable repeated stress.”

Do humans also experience impaired “cognitive function” and “hippocampal dysfunction” and “epigenetic alterations of neuroplasticity-related gene expression” caused by “inescapable, uncontrollable repeated stress”?

And what are the real histories of people who aren’t curious, who don’t show “a significant preference for the novel over the familiar object or location”?

http://www.pnas.org/content/112/23/7291.full “Basolateral amygdala bidirectionally modulates stress-induced hippocampal learning and memory deficits through a p25/Cdk5-dependent pathway”

An inhibitory gene that affects alcohol binge behavior

gettingwell4 2-3 stars Required further work, Beliefs, Cerebrum, Dopamine, Limbic system, Lower brain, Neurochemicals, Thalamus , , ,

This 2015 La Jolla rodent study found that an inhibitory gene affected alcohol binging behavior:

“Our study reveals the behavioral impact of this cellular effect, whereby the level of GIRK3 [the gene] expression in the VTA [ventral tegmental area] tunes ethanol intake under binge-type conditions: the more GIRK3, the less ethanol drinking.”

GIRK3-silenced mice still binged, though, and got alcohol’s rewarding effects through dopamine’s other neural pathways.

High concentrations of the gene were found in the thalamus part of the limbic system of wild-type mice, the control group. Per the study’s title, this gene presumably contributes to the thalamus’ overall function of gating information from limbic system and lower brain areas to reach the cerebrum and vice versa.

And the potential causes for reduced GIRK3 expression are..?? Hopefully – someday – researchers will be focused on finding causes for abnormal gene expression rather than being content to just study effects of abnormal gene expression. Until then, the usual practice of considering only the effects led these researchers to:

“Believe that a compound selectively targeting GIRK3-containing channels may hold promise for reducing alcohol consumption in heavy binge drinkers.”

http://www.pnas.org/content/112/22/7091.full “GIRK3 gates activation of the mesolimbic dopaminergic pathway by ethanol”

RNA as a proxy signal for context-specific biological activity

gettingwell4 2-3 stars Required further work, Brain development, Cerebrum, Hippocampus, Hypothalamus, Limbic system, Thalamus , ,

This 2015 Harvard/MIT rodent study was of long (more than 200 nucleotides) noncoding (non-protein coding) RNAs (ribonucleic acids). These are of interest because:

“Within the mammalian body, the largest repertoire and diversity of lncRNA genes outside the germ line occurs in the brain, where lncRNAs exhibit regional and cell-specific localization.

The expression patterns of lncRNAs may serve as a proxy signal for important, context-specific biological activity.”

The researchers explained what they could and couldn’t determine with current techniques and technologies:

“The whole-gene ablation method used here is often a first approach to determine the functionality of a locus.

Although each of these loci contains a lncRNA, it is important to consider that any observation resulting from this strategy could reflect the loss of any regulatory element in the deleted region.

The rate of lncRNA gene discovery has significantly outpaced our ability to evaluate both the physiological significance and function of these genes. It is difficult to predict whether the loss of any particular lncRNA locus will present a phenotype, but crucial information on the spatiotemporal dynamics of expression from each locus can provide significant direction and focus to downstream mechanistic studies by highlighting those loci most likely to have a physiological impact.

It is important to stress that no single method exists that can account for all possible mechanisms of action of a noncoding locus. Within these limits, the phenotypes observed after ablation of specific lncRNA loci confirm that expression of this class of noncoding RNAs can serve as a proxy signal to identify functional genomic loci with physiological relevance to disease and development, independent of whether this activity is directly ascribed to a functional lncRNA molecule.”

http://www.pnas.org/content/112/22/6855.full “Spatiotemporal expression and transcriptional perturbations by long noncoding RNAs in the mouse brain”

Stress in early life can alter physiology and behavior across the entire lifespan

gettingwell4 4-5 stars Advanced knowledge, Amygdala, Brain development, Cerebrum, Cortisol, Epigenetics, Hippocampus, Immune system, Limbic system, Memory, Neurochemicals, Stress, Testosterone , , , , , , , ,

I’ll quote a few sections of this 2014 summary of 111 studies concerning stress, including the authors’ research:

“The brain is the central organ of stress and adaptation to stressors because:

  • It not only perceives what is threatening or potentially threatening and initiates behavioral and physiological responses to those challenges,
  • But also is a target of the stressful experiences and the hormones and other mediators of the stress response.

The stress history of parents is a significant factor in the resilience of their offspring.

Environmental stress transduces its effects into lasting changes on physiology and behavior, which can vary even among genetically identical individuals.

Stress in early life can alter physiology and behavior across the entire lifespan.

Structural stress memory is even more apparent with regard to gene expression in stress-sensitive brain regions like the hippocampus.

Individual history is important and that there is a memory of stress history retained by neurons at the cellular level in regions like the hippocampus.

Stress has a number of known effects on epigenetic marks in the brain, producing alterations in DNA methylation and histone modifications in most of the stress-sensitive brain regions examined, including the hippocampus, amygdala, and prefrontal cortex.”

It seemed to be taboo to note that most of – and the largest of – detrimental effects of stress occurred during womb-life in the mother’s environment. The authors instead opted for a politically correct “the stress history of parents” phrase.

Referenced studies had findings relevant to the earliest periods of life, including Figure 1:

interactions

“Those organs that show the highest levels of retrotransposon [a repeat element (mobile DNA sequences often involved in mutations) type formed by copy-and-paste mechanisms] activity, such as the brain and placenta, also seem to be both steroidogenic and steroid-sensitive.”

However, Figure 1 was given a beneficial context, and other studies’ findings weren’t mentioned in their contexts of detrimental effects on fetuses of mothers who were stressed while pregnant.

http://www.pnas.org/content/112/22/6828.full “Stress and the dynamic genome: Steroids, epigenetics, and the transposome”

Running a marathon, cortisol, depression, causes, effects, and agendas

gettingwell4 < 0 Detracted from science, Cerebrum, Cortisol, Limbic system, Lower brain, Memory, Neurochemicals, Stress , ,

Let’s imagine that you decide you want to run a marathon. You haven’t run in six months, and you know you’ll have to train.

On the first day of training, as you run your first mile a friend pops out of nowhere and says, “You’re sweating! That means you’re going up to Mile 14 today! Good job, you’re on your way!”

You may appreciate the encouragement, but would a friend’s assessment have anything to do with your physical reality? Before you’ve run one mile, can an observer of your sweat say with certainty that you’ll run 14 miles on your first day of training?

Yeah. That’s how I felt when reading this 2014 UK study that found:

“Adolescent boys who have high levels of stress hormone ‘cortisol’ along with some symptoms of depression are at a 14 times higher risk of the condition than their peers.”

The researchers latched onto teenagers (12-16 years old, mean 13.7) to assess a psychiatric condition. They stated that a physical effect as common as visible sweat was a biomarker that predicted where some of the teenagers were going with their lives.

The study’s only physical measurements were cortisol from saliva samples at 8:00 a.m. on four consecutive days, then repeated a year later. For comparison, a standard lab test is to measure cortisol from saliva taken four times in one day at 9:00 a.m., 1:00 p.m., 5:00 p.m., and 9:00 p.m.

Cortisol is an effect of multiple potential causes, including stress, which itself is often an effect of multiple potential causes. One common cause of stress and its cortisol byproduct is diet, for example, when a person consumes caffeine.

“Mean time between waking and morning-cortisol collection was 50 min.”

I found it hard to believe that teenagers who:

  • woke up at 7:10 a.m.,
  • gulped down who knows what for breakfast,
  • got ready for, and then
  • went to school for an 8:00 a.m. cortisol test

wouldn’t have relatively “elevated morning cortisol” from the resultant stress.

Subjects self-reported depressive symptoms via a 33-item questionnaire initially and again every four months. They were interviewed for psychiatric diagnoses.

The largest separator used for stratification within subjects was an autobiographic memory test. Without this test, the study wouldn’t have made its main finding, so let’s look at the test’s details:

“Anxious and depressed adolescent patients report significantly elevated levels of over-general categoric memories compared with well controls. Six positive and six negative words are presented on flashcards in pseudorandom order, and participants are instructed to recall a particular memory of an event in their life after each word. Sixty seconds were allowed for each response.

Responses were categorized as specific if they referred to an event with a specific time and place, lasting no longer than 1 d[ay]. Responses were considered overgeneral if they formed a general class of repeated events.”

We can see that the autobiographical memory test only considered the subjects’ verbal expressions – within a short time period – of their recalls of emotionally triggered memories. As informed by the principles described in Agenda-driven research on emotional memories, the recall of an emotional memory is a product of the cerebrum responding to input from limbic system and lower brain areas. When someone describes their recall of an emotionally triggered memory, it’s yet another level further removed from the brain areas that store emotional memories.

We can also see that test scores of the subjects’ verbal expressions aren’t capable of providing any etiologic evidence for an effect of high cortisol. A correlation is the best that could ever be shown by an autobiographic memory test. Again, the study’s main finding hinged on this third-order observational method of trying to figure out what’s going on inside subjects’ brains.

The researchers developed a control group, and made only a token attempt to trace the control group teenagers’ histories:

“The primary caregiver was interviewed about the quality of the family environment in three epochs (0–5, 6–11, and 12–14 y of age).

Four classes were found: optimal class, aberrant parenting, discordant, and hazardous.”

Were we supposed to believe that any primary caregiver would tell the truth about anything in a teenager’s history that indicated they had damaged their child? Good luck with that.

Anyway, the researchers didn’t act as though teenagers’ histories had any significant relationships with any present or future conditions. Their ahistoric biases showed by subsequently processing the entire history of each of the control group teenagers into a 1 or a 0 for the model.

The researchers then modeled this binary assessment to be relevant to the study’s main subjects!

The researchers’ agenda led to predetermined findings. Was the reviewer onboard with this agenda?

  • By disregarding the main subjects’ histories, it couldn’t provide etiologic evidence for any present or future effects.
  • By measuring only early morning cortisol, are we surprised that model numbers could be processed into some correlation?
  • Comparing this sole measurement to 325 measurements taken of subjects in Assessing a mountain climber’s condition without noticing their empty backpack made me wonder about the study designers’ real intentions.

News coverage of the study jumped on its flimsy finding to demand that something must be done. What did researchers offer teenagers who needed help?

  • After citing research that:

    “Showed null effects for two active treatments [cognitive behavioral therapy (CBT) and attentional training, respectively]”

    they recommended some unspecific:

    “New models of public mental health education and intervention in the youth population.”

  • After citing research that found:

    “Current diagnostic classifications [e.g., the Diagnostic and Statistical Manual for Mental Disorders (DSM) and the International Classification of Diseases (ICD)] have proved to have low diagnostic validity for investigations on the etiology, prevention, or treatment of MD [major depression]“

    the study relied on these diagnoses anyway, and then disclaimed:

    “It may also be the case that current classifications, as used in this study, such as DSM and ICD are simply not optimally specified.”

They didn’t make their case that “elevated morning cortisol” effect was an adequate biomarker for teenagers who needed help. They did a disservice to their subjects by neither investigating nor providing any etiologic evidence for observed effects.

Who really benefited from this underlying agenda? I didn’t see that it was teenagers who may have actually needed assistance.

Did the study’s funders know that these efforts had enormous lacks? And what did:

“New models of public mental health education and intervention in the youth population”

really mean?

http://www.pnas.org/content/111/9/3638.full “Elevated morning cortisol is a stratified population-level biomarker for major depression in boys only with high depressive symptoms”

One way beliefs produce pleasure and reward in the cerebrum

gettingwell4 4-5 stars Advanced knowledge, Beliefs, Cerebrum, Dopamine, Neurochemicals ,

This 2014 Singapore human study found:

“Differences in belief learning – the degree to which players were able to anticipate and respond to the actions of others, or to imagine what their competitor is thinking and respond strategically – was associated with variation in three genes which primarily affect dopamine functioning in the medial prefrontal cortex.

In contrast, differences in trial-and-error reinforcement learning – how quickly they forget past experiences and how quickly they change strategy – was associated with variation in two genes that primarily affect striatal dopamine.”

One of the researchers said:

“The findings correlate well with previous brain studies showing that the prefrontal cortex is involved in belief learning, while the striatum is involved in reinforcement learning.”

The study didn’t demonstrate cause and effect, however, and the researchers cautioned:

“It would be mistaken to interpret our results as suggesting that dopamine genes function as “belief learning genes.”

The study added to the science of how beliefs act on the pleasure and reward parts of the cerebrum.

http://www.pnas.org/content/111/26/9615.full.pdf “Dissociable contribution of prefrontal and striatal dopaminergic genes to learning in economic games” (the pdf file is linked because the html had errors)

Limits of dMRI brain studies

gettingwell4 2-3 stars Required further work, Cerebrum

This 2015 macaque study found:

“∼50% of the cortical surface was effectively inaccessible for long-range diffusion tracking.

Current and future high-resolution dMRI [diffusion magnetic resonance imaging] studies of the human brain will need to develop methods to overcome the challenges posed by superficial white matter systems to determine long-range anatomical connections accurately.”

The researchers stated:

“Although in many respects the macaque brain is a good approximation of the human brain, both species have undergone profound evolutionary changes since the time of their most recent common ancestor living more than 20 million years ago, particularly in regard to the massive expansion of the cerebral cortex in the human brain. Thus, it is of great value to assess human anatomical connections directly and comprehensively.”

Sound familiar? That’s also the point I made in Do popular science memes justify researchers’ cruelties to monkeys?

http://www.pnas.org/content/112/21/E2820.full “Superficial white matter fiber systems impede detection of long-range cortical connections in diffusion MR tractography”

The thalamus part of the limbic system has a critical period for connections

gettingwell4 2-3 stars Required further work, Anterior cingulate cortex, Brain development, Cerebrum, Limbic system, Lower brain, Primal Therapy, Thalamus , , ,

This highly-jargoned 2015 UK study found that connections made by the thalamus of the developing human fetus had a critical period of the last trimester of womb-life. Babies born before the 33rd week of gestation experienced thalamic disconnections compared with normal-term babies and adults. The disconnections increased with a shorter womb-life.

The thalamus of premature babies also developed stronger connections with areas of the face, lips, tongue, jaw, and throat. They presumably needed these connections for survival actions such as breathing and feeding that aren’t a part of the last trimester of womb-life.

The study confirmed that the structures of thalamic connections of normal-term babies were very similar to those of adults. The study added to the research that shows that human limbic systems and lower brains closely approximate their lifelong functionalities at the normal time of birth.

It was difficult to measure the thalamus at this stage of life with current technology, and the researchers had to discard over two-thirds of their results. The researchers recommended monitoring these premature babies for difficulties in later childhood that may be caused by their early-life experiences.

Why would this monitoring recommendation apply to just the study’s subjects? We know from other studies that a main purpose of thalamic connections is to actively control and gate information to and from the cerebrum.

Would it make sense for a medical professional to disregard any patient’s birth history if they had problems in their brain’s gating functions or connectivity?

One researcher said:

“The ability of modern science to image the connections in the brain would have been inconceivable just a few years ago, but we are now able to observe brain development in babies as they grow, and this is likely to produce remarkable benefits for medicine.”

This study’s results provided evidence for a principle of Dr. Arthur Janov’s Primal Therapy: the bases for disconnection from aspects of oneself are often set down during gestation. The “remarkable benefits for medicine” are more likely to be along the lines of what I describe in my Scientific evidence page.

http://www.pnas.org/content/112/20/6485.full “Specialization and integration of functional thalamocortical connectivity in the human infant”