2-3 stars Required further work

Research needing further work

Are you feeling kinda blue? Think your brain cells are too few? Get your fat cells on that bike and ride!

gettingwell4 2-3 stars Required further work, Hippocampus, Limbic system

This 2014 rodent study found that fat cells released a certain hormone during exercise that produced two beneficial effects:

  • the hormone increased hippocampal neurogenesis;
  • it also reduced depression-like behaviors.

So if you’re feeling kinda blue,

Think your brain cells are too few?

Get your fat cells on that bike and ride!

http://www.pnas.org/content/111/44/15810.full “Physical exercise-induced hippocampal neurogenesis and antidepressant effects are mediated by the adipocyte hormone adiponectin”

A biologically relevant event can drive long-term memory in a single training session

gettingwell4 2-3 stars Required further work, Brain development, Dopamine, Epigenetics, Memory, Neurochemicals

This 2014 fruit fly study found:

“A biologically relevant event such as finding food under starvation conditions or being poisoned can drive long-term memory in a single training session.”

I don’t think that we need to discover at these extremes, though, whether or not the finding has human applicability.

We do know from the Dutch hunger winter of 1944 study referenced in the Non-PC alert: Treating the mother’s obesity symptoms positively affects the post-surgery offspring study that prenatal exposure to famine had lifelong ill effects on the children. The exposed children had epigenetic DNA changes – a form of long-term memory – from their mothers’ starvation, which resulted in relative obesity compared with their unexposed siblings.

http://www.pnas.org/content/112/2/578.full “Distinct dopamine neurons mediate reward signals for short- and long-term memories”

What is the purpose of music? A review of evolutionary and pleasurable research findings

gettingwell4 2-3 stars Required further work, Amygdala, Anterior cingulate cortex, Cerebrum, Dopamine, Hippocampus, Hypothalamus, Limbic system, Lower brain, Neurochemicals

Ever wonder what happens in your brain and body when you get chills from a musical performance?

This 2013 summary review of 126 studies provided details of brain areas that contribute to our enjoyment of music.

Much of the review addressed Darwin’s observation that music had no readily apparent functional consequence and no clear-cut adaptive function. The researchers noted that:

“There is scant evidence that other species possess the mental machinery to decode music in the way humans do, or to derive enjoyment from it.”

The reasons why different types of music affect us differently are similar to the findings of the Reciprocity behaviors differ as to whether we seek cerebral vs. limbic system rewards study.

Here are the “We seek limbic system rewards” similarities:

“The nucleus accumbens played an important role with both familiar and novel music. In the case of familiar music, hemodynamic activity in the nucleus accumbens was associated with increasing pleasure, and maximally expressed during the experience of chills, which represent the peak emotional response; these were the same regions that showed dopamine release. The nucleus accumbens is tightly connected with subcortical limbic areas of the brain, implicated in processing, detecting, and expressing emotions, including the amygdala and hippocampus. It is also connected to the hypothalamus, insula, and anterior cingulate cortex, all of which are implicated in controlling the autonomic nervous system, and may be responsible for the psychophysiological phenomena associated with listening to music and emotional arousal.”

Here is the “We seek cerebral rewards” part.

“Finally, the nucleus accumbens is tightly integrated with cortical areas implicated in “high-level” processing of emotions that integrate information from various sources, including the orbital and ventromedial frontal lobe. These areas are largely implicated in assigning and maintaining reward value to stimuli and may be critical in evaluating the significance of abstract stimuli that we consider pleasurable.”

http://www.pnas.org/content/110/Supplement_2/10430.full “From perception to pleasure: Music and its neural substrates”

Using expectations of oxytocin to induce positive placebo effects of touching

gettingwell4 2-3 stars Required further work, Amygdala, Beliefs, Brain hemispheres, Limbic system, Neurochemicals, Oxytocin, Thalamus

This 2013 Scandinavian study detailed which brain structures were involved when fooling oneself about actual sensations in favor of expected sensations.

It was hilarious how the researchers used studies of oxytocin to create expectations in the subjects:

“To induce expectation of intranasal oxytocin’s beneficial effects on painful and pleasant touch experience, participants viewed a 6-min locally developed video documentary about oxytocin’s putative prosocial effects such as involvement in bonding, love, grooming, affective touch, and healing. As all of the material was based on published research, there was no deception. The video concluded that a nasal spray of oxytocin might enhance the pleasantness of:

  • (i) stroking and
  • (ii) warm touch, and
  • (iii) reduce the unpleasantness of pain.”

Other items:

  • Only the placebo effects for the warm and pain-reducing touches were statistically significant, not the stroking touch;
  • The a priori brain areas monitored in the “sensory circuitry” included the thalamus and were all in the right brain hemisphere;
  • The a priori brain areas monitored in the “emotional appraisal circuitry” included the amygdala.

One way the researchers summarized the study was:

“Pain reduction dampened sensory processing in the brain, whereas increased touch pleasantness increased sensory processing.”

This finding demonstrated how the thalamus part of the limbic system actively controls and gates information to and from the cerebrum, similar to the Thalamus gating and control of the limbic system and cerebrum is a form of memory study.

There was a terminology problem in the study, evidenced by statements such as:

“We induced placebo improvement of both negative and positive feelings (painful and pleasant touch).”

Touch is a sensation, not a feeling or emotion. This placebo study created expectations of sensations in the subjects’ cerebrums, not expectations of emotions.

Also, including parts of the limbic system such as the amygdala in the “emotional appraisal circuitry” didn’t mean that the researchers studied feelings or emotions. We know from research summarized in the Conscious mental states should not be the first-choice explanation of behavior study that:

“Neither amygdala activity nor amygdala-controlled responses are telltale signatures of fearful feelings.“

The current study cast additional light on the dubious Problematic research on human happiness study. Those researchers were fooled by a positive placebo effect!

http://www.pnas.org/content/110/44/17993.full “Placebo improves pleasure and pain through opposite modulation of sensory processing”

DNA methylation is the most frequent way that duplicate genes are epigenetically silenced

gettingwell4 2-3 stars Required further work, Epigenetics

This 2014 human study showed that DNA methylation was the most frequent way that duplicate genes were epigenetically silenced. Current thinking is that at least half of the genes in the human genome are inactive duplicates.

The study stated:

“Duplicate genes are essential and ongoing sources of genetic material.”

What the researchers didn’t show, however, was that duplicate genes evolve per the study’s title “evolution of duplicate genes.” It was misleading to imply in the study’s headline that duplicate genes evolve.

Evolution occurs as organisms adapt to their environments. Duplicate genes aren’t active in the adaptation process when they are silenced.

http://www.pnas.org/content/111/16/5932.full “DNA methylation and evolution of duplicate genes”

Is oxytocin why more women than men like horror movies?

gettingwell4 2-3 stars Required further work, Amygdala, Brain hemispheres, Limbic system, Neurochemicals, Oxytocin, Serotonin

This 2014 human study showed how oxytocin regulates serotonin with the involvement of the right part of the amygdala.

The following passage caught my eye as a possible explanation of why more women than men prefer horror movies: oxytocin?

“We have chosen to enroll male subjects only to avoid the confounding effects linked to sex and a possible interaction with gonadal steroids. Indeed, as shown by previous studies, oxytocin modulates brain activity differently in male and female subjects.

For instance, oxytocin suppresses amygdala response to emotionally threatening stimuli in males but enhances the same response in females.“

http://www.pnas.org/content/111/23/8637.full “Switching brain serotonin with oxytocin”

Our long-term memory usually selects what we pay closer visual attention to

gettingwell4 2-3 stars Required further work, Memory

This 2014 human study at Vanderbilt found that our long-term memory usually selects what we pay closer visual attention to:

“Improvements in attentional tuning were accompanied by changes in an electrophysiological signal hypothesized to index long-term memory.”

The focus was on electrical fields, leading to predictable statements:

“Follow-up studies using neuroimaging techniques are needed to identify definitively the brain areas and associated networks responsible for the rapid changes in perceptual attention we observed.”

The researchers also found that 20 minutes of electrical brain stimulation helps tune perceptual attention. Is it in vogue that attention studies like this one and Can psychologists exclude the limbic system and adequately study awareness and social cognition? seemed to need gadgets that zapped the subjects’ brains?

http://www.pnas.org/content/112/2/625.full “Enhancing long-term memory with stimulation tunes visual attention in one trial”

Teenagers value rewards more and are more sensitive to punishments than are adults

gettingwell4 2-3 stars Required further work, Beliefs, Brain development, Brain hemispheres, Cerebrum, Limbic system

This 2013 human study found that adolescents placed more value on rewards than did adults. Adolescents were also more sensitive to punishments than were adults.

Cerebral areas increased activity when the expected value of the reward increased. Limbic system areas increased activity when the expected value of the reward decreased.

The left ventral striatum was the brain area that had the most increase in activity in adolescents compared with adults when the expected value of the reward increased. This brain area is usually not fully developed until people are in their mid 20s.

As the researchers noted as a limitation of the study:

“Without including preadolescents it is not possible to say with certainty whether the observed difference is a uniquely adolescent sensitivity to expected value or part of an ongoing developmental trajectory.”

Another limitation of the study was that it studied only 22 teens aged 13 to 17. Nineteen adults were studied with an average age of 28.

http://www.pnas.org/content/111/4/1646.full “Neural representation of expected value in the adolescent brain”

When do you get to live your own life?

gettingwell4 2-3 stars Required further work, Limbic system, Lower brain

This 2014 Cambridge/Stanford study asserted that for Facebook users, a computer can be a better judge of who your real self is: better than your social contacts, and in some aspects, than yourself.

There were many elements to this study. Let’s take one – impulsivity – which should be a multifaceted judgment relating to one’s own limbic system and especially lower brain, whose signature is instinctual survival reactions.

The self-assessed correlation score was .52, which was better than the computer score of .28, which was better than the .26 social contacts score.

I interpreted the impulsivity scores as people internally knowing who they really were better than what they displayed externally. A finding of the “duh” variety, although not counter to the study’s headlines.

What do you think about this study’s statement?

“Furthermore, in the future, people might abandon their own psychological judgments and rely on computers when making important life decisions, such as choosing activities, career paths, or even romantic partners. It is possible that such data-driven decisions will improve people’s lives.”

I think that’s generally possible. Whether that’s individually possible depends on who you really are.

If all your life you’ve accepted being constantly told what to do, and accepted being forced to do things “for your own good” then yes, you may accept a computer program as a substitute for your parents’ or some other external party’s authority over your life.

If this describes you, I ask: When do you get to live your own life?

http://www.pnas.org/content/112/4/1036.full “Computer-based personality judgments are more accurate than those made by humans”

Measuring the effectiveness of scientific gatekeeping

gettingwell4 2-3 stars Required further work

This 2014 study found that unconventional and groundbreaking research was routinely rejected by medical journals:

“Our research suggests that evaluative strategies that increase the mean quality of published science may also increase the risk of rejecting unconventional or outstanding work.”

The study was also a collateral indication of the degree to which peer reviewers didn’t try to advance science.

http://www.pnas.org/content/112/2/360.full “Measuring the effectiveness of scientific gatekeeping”

This post has somehow become a target for spammers, and I’ve disabled comments. Readers can comment on other posts and indicate that they want their comment to apply here, and I’ll re-enable comments.

Why do researchers title their study the cortex vs. the limbic system or lower brain?

gettingwell4 2-3 stars Required further work, Brain development, Brainstem, Cerebrum, Limbic system, Lower brain, Stress ,

This 2012 review of 89 studies was ostensibly of the prefrontal cortex. The review title showed how researchers characterize their work as studying the cerebrum, even when they primarily deal with the limbic system and lower brains.

For example, the reviewer discussed rodent studies of the developing pup fetus regarding:

  • Sensory/motor – Paternal complex housing, maternal complex housing
  • Stress – Mild stress, bystander stress, moderate stress
  • Psychoactive drugs – Stimulants
  • Adult stimulants – Ethanol

The active brain areas of the rodent fetus are the brainstem and the limbic system, and those areas were primarily what was studied. The cerebrum of the developing pup is a tiny strip that has little cognitive function.

http://www.pnas.org/content/109/Supplement_2/17186.full “Experience and the developing prefrontal cortex”

Face-selective neurons maintain consistent visual responses across months

gettingwell4 2-3 stars Required further work, Brain development, Memory

This 2014 primate study provided additional details on the specialized brain circuits for recognizing faces:

“The current finding that neurons commonly give similar responses upon seeing the same faces months apart raises the possibility that some neurons might respond the same way to the same individual faces over most of the animal’s lifespan.”

But the finding could also have been:

“Another example of a biological system maintaining its complex organization as the constituent components are exchanged.”

http://www.pnas.org/content/111/22/8251.full “Face-selective neurons maintain consistent visual responses across months”

Both sexes can be skilled child caregivers when we put time and effort into it

gettingwell4 2-3 stars Required further work, Amygdala, Brain development, Cerebrum, Limbic system

My POV of this 2014 Israeli study’s findings, at the risk of being dragged into the politically-correct quagmire:

  • Mothers (heterosexual primary-caregiving) mainly used areas of their limbic systems to care for children;
  • Fathers (heterosexual secondary-caregiving) mainly used areas of their cerebrums to care for children;
  • Fathers (homosexual primary-caregiving) mainly used both their limbic systems and cerebrums to care for children.

Findings of the “duh” variety:

  • Women have a built-in capacity to care for children before they have children;
  • Men can learn to care for children;
  • Both sexes can be skilled child caregivers when we put time and effort into it.

“Although only mothers experience pregnancy, birth, and lactation, and these provide powerful primers for the expression of maternal care via amygdala sensitization, evolution created other pathways for adaptation to the parental role in human fathers, and these alternative pathways come with practice, attunement, and day-by-day caregiving.”

http://www.pnas.org/content/111/27/9792.full “Father’s brain is sensitive to childcare experiences”

Improvements in tracking and predicting single cell epigenetic changes during embryonic development

gettingwell4 2-3 stars Required further work, Brain development, Epigenetics, Immune system

This 2014 Harvard rodent study demonstrated improvements in tracking and predicting how, during embryonic development, a cell’s environment epigenetically changed the cell’s genetic expression. The researchers stated applicability to human B-cell development in the immune system.

http://www.pnas.org/content/111/52/E5643.full “Bifurcation analysis of single-cell gene expression data reveals epigenetic landscape”

The thalamus’ role in coordinating REM sleep stages

gettingwell4 2-3 stars Required further work, Brainstem, Limbic system, Lower brain, Memory, Thalamus

This 2013 human study provided more details about dream sleep. The thalamus portion of the limbic system coordinates REM stages, which play critical roles in learning and memory.

This study also noted that science assigns no functions to dreams themselves, which was the first I’d heard of it.

http://www.pnas.org/content/110/25/10300.full “Rhythmic alternating patterns of brain activity distinguish rapid eye movement sleep from other states of consciousness”