Let it burn

You've reached Fiend's personal blog. Mostly reblogs and textposts about needless things.

[fyp-psychology]

For years mental health professionals taught people that they could be psychologically healthy without social support, that ‘unless you love yourself, no one else will love you’ …The truth is, you cannot love yourself unless you have been loved and are loved. The capacity to love cannot be built in isolation.

Bruce D. Perry, The Boy Who Was Raised as a Dog  (via fyp-philosophy)

[neurosciencestuff]

Split brain does not lead to split consciousness

A new research study contradicts the established view that so-called split-brain patients have a split consciousness. Instead, the researchers behind the study, led by UvA psychologist Yair Pinto, have found strong evidence showing that despite being characterised by little to no communication between the right and left brain hemispheres, split brain does not cause two independent conscious perceivers in one brain. Their results are published in the latest edition of the journal Brain. 

Split brain is a lay term to describe the result of a corpus callosotomy, a surgical procedure first performed in the 1940s to alleviate severe epilepsy among patients. During this procedure, the corpus callosum, a bundle of neural fibres connecting the left and right cerebral hemispheres, is severed to prevent the spread of epileptic activity between the two brain halves. While mostly successful in relieving epilepsy, the procedure also virtually eliminates all communication between the cerebral hemispheres, thereby resulting in a ‘split brain’.

This condition was made famous by the work of Nobel laureate Roger Sperry and Michael Gazzaniga. In their canonical work, Sperry and Gazzaniga discovered that split-brain patients can only respond to stimuli in the right visual field with their right hand and vice versa. This was taken as evidence that severing the corpus callosum causes each hemisphere to gain its own consciousness.

Divided perception

For their study, Pinto and his fellow researchers conducted a series of tests on two patients who had undergone a full callosotomy. In one of the tests, the patients were placed in front of a screen and shown various objects displayed in several locations. The patients were then asked to confirm whether an object appeared and to indicate its location. In another test, they had to correctly name the object they had seen, a notorious difficulty among spit-brain patients. ‘Our main aim was to determine whether the patients performed better when responding to the left visual field with their left hand instead of their right hand and vice versa’, says Pinto, assistant professor of Cognitive Psychology. ‘This question was based on the textbook notion of two independent conscious agents: one experiencing the left visual field and controlling the left hand, and one experiencing the right visual field and controlling the right hand.’

To the researchers’ surprise, the patients were able to respond to stimuli throughout the entire visual field with all the response types: left hand, right hand and verbally. Pinto: ‘The patients could accurately indicate whether an object was present in the left visual field and pinpoint its location, even when they responded with the right hand or verbally. This despite the fact that their cerebral hemispheres can hardly communicate with each other and do so at perhaps 1 bit per second, which is less than a normal conversation. I was so surprised that I decide repeat the experiments several more times with all types of control.’

(Image caption: A depiction of the traditional view of the split brain syndrome (top) versus what the researchers actually found in two split-brain patients across a wide variety of tasks (bottom). Credit: Yair Pinto)

Undivided consciousness

According to Pinto, the results present clear evidence for unity of consciousness in split-brain patients. ‘The established view of split-brain patients implies that physical connections transmitting massive amounts of information are indispensable for unified consciousness, i.e. one conscious agent in one brain. Our findings, however, reveal that although the two hemispheres are completely insulated from each other, the brain as a whole is still able to produce only one conscious agent. This directly contradicts current orthodoxy and highlights the complexity of unified consciousness.’

In the coming period, Pinto plans to conduct research on more split-brain patients to see whether his findings can be replicated. ‘These patients, who are rapidly decreasing in numbers, are our only way to find out what happens when large subsystems in the brain no longer communicate with each other. This phenomenon raises important questions that cannot be investigated in healthy adults because we have no technique to isolate large subsystems in healthy brains.’

[wnq-anonymous]

When someone is going through a storm, your silent presence is more powerful than a million, empty words.

Thema Davis (via wnq-anonymous)

[gunstellations]

I abuse the battle system in this game

[wordsnquotes]

Sometimes skulls are thick. Sometimes hearts are vacant. Sometimes words don’t work.

James Frey, A Million Little Pieces (via wordsnquotes)

[wordsnquotes]

Don’t allow your wounds to turn you into a person you are not.

Paulo Coelho (via wordsnquotes)

[neurosciencestuff]

(Image caption: MRI Coronal View of the Amygdala. Credit: Amber Rieder, Jenna Traynor, Geoffrey B. Hall)

Mounting Challenge to Brain Sex Differences

How different are men and women’s brains?

The latest evidence to address this controversy comes from a meta-analysis of human amygdala volumes conducted by two Rosalind Franklin University students, Dhruv Marwha, CMS ‘18 and Meha Halari, CMS ‘18, working with Lise Eliot, PhD, CMS associate professor of neuroscience.

In their study, Dhruv and Meha systematically identified all MRI studies comparing amygdala volume in men and women over the past 30 years. Using meta-analysis, a statistical approach for combining the results of multiple studies, the team found no significant difference between the sexes.

“Despite the common impression that men and women are profoundly different, large analyses of brain measures are finding far more similarity than difference,“ Dr. Eliot said. "There is no categorically ‘male brain’ or 'female brain,’ and much more overlap than difference between genders for nearly all brain measures.”

It took six months to examine thousands of papers and extract data for the study, according to Dhruv, a self-described “math and computer geek” who ran the statistical meta-analysis.

“Going through the papers was grueling work,” he said. “The meta-analysis was the fun part; finding trends, comparing amygdala volume to see if it changed by subgroups within the data.”

The olive-sized amygdala is a key brain structure involved in all types of emotion and in social behaviors such as aggression and sexual arousal. Animal studies and early MRI reports indicated that the amygdala is disproportionately larger in males’ brains. Such a size difference has been suggested to contribute to sex differences in emotionality and in the prevalence of disorders such as anxiety and depression.

Biologists use the term “sexually dimorphic” (literally, “two different forms”) to describe male-female differences. This new study shows that the term does not apply to human amygdala volume. It joins other recent research that challenges the concept of binary “male” and “female” human brains, and may have relevance to understanding disorders including depression, substance abuse, and gender dysphoria.

The CMS study identified 58 published comparisons of amygdala volume in matched groups of healthy men and women (or boys and girls) that included 6,726 total participants. Studies reporting raw amygdala volume show that the structure is indeed about 10 percent larger in male brains. However, this difference is comparable to males’ larger body size, including the 11-12 percent larger volume of males’ brains overall. Among studies that reported amygdala volumes corrected for overall brain size, the volume difference was negligible (<0.1 percent in the right amygdala, 2.5 percent in the left amygdala) and not statistically significant.

The study appeared in the December volume of the journal NeuroImage.

“I’m really excited and impressed by the resources made available by RFU for this study and Dr. Eliot’s willingness to help,” said Dhruv, first author on the paper.

“There’s a long-held idea that males and females are really different and there must be a [neurological] reason for it,” he said. “We’re working to decipher if that’s truly the case.”

In another 2015 meta-analysis, Dhruv also worked with Dr. Eliot and first author Anh Tan, MD ’16, to debunk the widely-held belief that the brain’s hippocampus, which consolidates new memories, is larger in women than men.

“There are behavioral reasons to suspect a sex difference in the amygdala,” Dr. Eliot said. “Emotion, empathy, aggression, and sexual arousal all depend on it. Also, the evidence from animal studies suggesting a sex difference in amygdala volume is stronger than it is for the hippocampus. So this finding is more surprising than our hippocampal result and suggests that human brains are not as sexually dimorphic as rats.”

This study strengthens the case for gender similarity in the human brain and psychological abilities and has implications for efforts to understand the transgender brain.

[felderwin]

my favorite thing i’ve learned in college is that way back in ancient china there was this poet/philosopher guy who wrote this whole pretentious poem about how enlightened he was that was like “the eight winds cannot move me” blahblahblah and he was really proud of it so he sent it to his friend who lived across the lake and then his friend sends it back and just writes “FART” (or the ancient Chinese equivalent) on it and he was SO MAD he travels across the lake to chew his friend out and when he gets there his friend says “wow. the eight winds cannot move you, but one fart sends you across the lake”

[lalalalack]

イシュタル

[angelfood1995]

……….yugioh is too much

[yokotanji]

[yokotanji]

[ericlingenfelter]

There are not enough question marks in the world for this.

[the-x-button]

[neurosciencestuff]

“Sixth sense” may be more than just a feeling

With the help of two young patients with a unique neurological disorder, an initial study by scientists at the National Institutes of Health suggests that a gene called PIEZO2 controls specific aspects of human touch and proprioception, a “sixth sense” describing awareness of one’s body in space. Mutations in the gene caused the two to have movement and balance problems and the loss of some forms of touch. Despite their difficulties, they both appeared to cope with these challenges by relying heavily on vision and other senses.

“Our study highlights the critical importance of PIEZO2 and the senses it controls in our daily lives,” said Carsten G. Bönnemann, M.D., senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and a co-leader of the study published in the New England Journal of Medicine. “The results establish that PIEZO2 is a touch and proprioception gene in humans. Understanding its role in these senses may provide clues to a variety of neurological disorders.”

Dr. Bönnemann’s team uses cutting edge genetic techniques to help diagnose children around the world who have disorders that are difficult to characterize. The two patients in this study are unrelated, one nine and the other 19 years old. They have difficulties walking; hip, finger and foot deformities; and abnormally curved spines diagnosed as progressive scoliosis.

Working with the laboratory of Alexander T. Chesler, Ph.D., investigator at NIH’s National Center for Complementary and Integrative Health (NCCIH), the researchers discovered that the patients have mutations in the PIEZO2 gene that appear to block the normal production or activity of Piezo2 proteins in their cells. Piezo2 is what scientists call a mechanosensitive protein because it generates electrical nerve signals in response to changes in cell shape, such as when skin cells and neurons of the hand are pressed against a table. Studies in mice suggest that Piezo2 is found in the neurons that control touch and proprioception.

“As someone who studies Piezo2 in mice, working with these patients was humbling,” said Dr. Chesler. “Our results suggest they are touch-blind. The patient’s version of Piezo2 may not work, so their neurons cannot detect touch or limb movements.”

Further examinations at the NIH Clinical Center suggested the young patients lack body awareness. Blindfolding them made walking extremely difficult, causing them to stagger and stumble from side to side while assistants prevented them from falling. When the researchers compared the two patients with unaffected volunteers, they found that blindfolding the young patients made it harder for them to reliably reach for an object in front of their faces than it was for the volunteers. Without looking, the patients could not guess the direction their joints were being moved as well as the control subjects could.

The patients were also less sensitive to certain forms of touch. They could not feel vibrations from a buzzing tuning fork as well as the control subjects could. Nor could they tell the difference between one or two small ends of a caliper pressed firmly against their palms. Brain scans of one patient showed no response when the palm of her hand was brushed.

Nevertheless, the patients could feel other forms of touch. Stroking or brushing hairy skin is normally perceived as pleasant. Although they both felt the brushing of hairy skin, one claimed it felt prickly instead of the pleasant sensation reported by unaffected volunteers. Brain scans showed different activity patterns in response to brushing between unaffected volunteers and the patient who felt prickliness.

Despite these differences, the patients’ nervous systems appeared to be developing normally. They were able to feel pain, itch, and temperature normally; the nerves in their limbs conducted electricity rapidly; and their brains and cognitive abilities were similar to the control subjects of their age.

“What’s remarkable about these patients is how much their nervous systems compensate for their lack of touch and body awareness,” said Dr. Bönnemann. “It suggests the nervous system may have several alternate pathways that we can tap into when designing new therapies.”

Previous studies found that mutations in PIEZO2 may have various effects on the Piezo2 protein that may result in genetic musculoskeletal disorders, including distal arthrogryposis type 5, Gordon Syndrome, and Marden-Walker Syndrome. Drs. Bönnemann and Chesler concluded that the scoliosis and joint problems of the patients in this study suggest that Piezo2 is either directly required for the normal growth and alignment of the skeletal system or that touch and proprioception indirectly guide skeletal development.

“Our study demonstrates that bench and bedside research are connected by a two-way street,” said Dr. Chesler. “Results from basic laboratory research guided our examination of the children. Now we can take that knowledge back to the lab and use it to design future experiments investigating the role of PIEZO2 in nervous system and musculoskeletal development.”

[geckospots-blog]

Thinking about limits

5.6 The limits of my language mean the limits of my world.

5.61 Logic pervades the world: the limits of the world are also its limits.

5.632 The subject does not belong to the world: rather, it is a limit of the world.

Ludwig Wittgenstein (Tractatus Logico-Philosophicus)

If the limit discovered by rebellion transfigures everything, if every thought, every action that goes beyond a certain point negates itself, there is, in fact, a measure by which to judge events and men.

Albert Camus (’Moderation and Excess’ in The Rebel)

[wordsnquotes]

The poison leaves bit by bit, not all at once. Be patient. You are healing.

Yasmin Mogahed (via fyp-philosophy)

[neurosciencestuff]

A microRNA plays role in major depression

A tiny RNA appears to play a role in producing major depression, the mental disorder that affects as many as 250 million people a year worldwide.

Major depression, formally known as major depressive disorder, or MDD, brings increased risk of suicide and is reported to cause the second-most years of disability after low-back pain.

University of Alabama at Birmingham researchers have found that amounts of this microRNA are significantly elevated in the brains of experimental rats with induced depression from corticosterone treatment, in the post-death brains of humans diagnosed with MDD and in peripheral blood serum from living patients with MDD, according to a study by led by Yogesh Dwivedi, Ph.D., the Elesabeth Ridgely Shook Endowed Professor and director of Translational Research, UAB Mood Disorders Program, Department of Psychiatry.

This microRNA — miR-124-3p — is thus a potential therapeutic target for novel drug development, and it can serve as a putative biomarker for MDD pathogenesis.

Micro RNAs, or miRNAs, interact with messenger RNA after the miRNA is exported from the cell nucleus and processed by a team of enzymes. MiRNAs are robust players of gene regulation in cells, and there are more than 1,300 different miRNAs at work in the brain.

In previous work, Dwivedi and colleagues had seen that a set of miRNAs were coordinately regulated in the prefrontal cortex of the brains of MDD subjects. The prefrontal cortex, known for controlling the executive function of the brain, is critically involved in the response to stress, by regulating the endocrine glands known as the hypothalamic-pituitary-adrenal axis. The adrenal gland produces the stress hormone cortisol in humans and corticosterone in rodents.

To see if stress plays a role in the coordinated regulation of prefrontal cortex miRNAs, the UAB researchers then turned to a rat depression model. They found that rats treated with corticosterone to induce depression-like behavior showed coordinated dysregulation of miRNAs in the prefrontal cortex, and the most significantly affected miRNA was miR-124-3p.

Their current paper, previewed in the journal Neuropsychopharmacology, examined the relevance of miR-124-3p in MDD pathogenesis.

Using computer analysis of genome sequences, the researchers:

Identified eight highly potential target genes for binding by miR-124-3p, genes whose function is also reported to be critical in brain physiology during stress and MDD pathogenesis. Four of these potential target genes were significantly down-regulated in the prefrontal cortex of corticosterone-treated rats, and this down-regulation inversely correlated with miR-124-3p levels.

Showed that the four genes that were significantly down-regulated have evolutionarily conserved miR-124-3p binding sites across a wide range of higher vertebrate species.

In neuroblastoma cells grown in culture:

Overexpression of miR-124-3p caused significant down-regulation for two of the potential target genes.

In prefrontal cortex neurons from depression-model rats treated with corticosterone:

Significant binding by miR-124-3p to two of the potential target genes was seen, as measured from immunoprecipitated RNA-induced silencing complexes.

The locus-specific origin of for mature miR-124-3p was identified at a site on chromosome 3, out of three possible chromosomal sites, and two CpG “islands” that can act as sites from epigenetic modification by DNA methylation were identified near the miR-124 gene promoter on chromosome 3.

This miR-124-3 promoter was found to be hypo-methylated in the corticosterone-treated rats, and the gene expression of one DNA methyltransferase — Dnmt3a — was significantly repressed.

For humans:

In post-mortem brains of 15 controls and 15 MDD subjects, the MDD group showed significant increase in the expression of miR-124-3p, and expression of three of the potential target genes was significantly lower.

The level of miR-124-3p was significantly higher in the serum of 18 antidepressant-free MDD patients, as compared with 17 healthy controls.

“Altogether,” the UAB researchers conclude, “this is the first comprehensive and mechanistic study at in-vitro and in-vivo levels which demonstrates that, not only are there consistent depression-associated changes in the expression of miR-124-3p across different species, but also the genes that are targets of this miRNA are highly dysregulated, showing altered response at functional level.”