parietal cortex

So I just read this article about how people end up fucking up whatever task they’re doing when they feel like they’re being watched.  Scientists have discovered that the sense of being observed actually SHUTS OFF a part of the brain, the inferior parietal cortex. 


Given the fact that women are constantly watched in our society, and we are constantly REMINDED that we are being watched by people making fun of fat, “ugly”, or gender-nonconforming women, it makes me wonder how many women have messed up important tasks or projects or just day-to-day activities because A PART OF OUR BRAIN is permanently being deactivated?


Like talk about a fucking handicap.


Women are constantly held under the microscope- whether we are attractive or unattractive, the gaze of patriarchy never ends.


Just last week I was walking my dog and bent over to literally pick up poop.  Suddenly I heard whistling and looked up cause I knew I was the only person around.  Sure enough, about 300 feet away, some construction worker was perched on top of a building, grinning at me and calling out stuff I luckily couldn’t hear because he was so goddamn far away.


I wonder what it does to women to have this constant source of stress hanging over us, each and every day, knowing we are being scrutinized and examined no matter what we’re doing.  I wonder how many more accomplishments, life-changing discoveries, inventions, etc would have been achieved by women if we didn’t have this constant brain-handicap imposed on us by men.

Structure/function: The Parietal Lobe

Behold! Your parietal lobe! You can thank this lobe for your ability to slap yourself in the face! You’re welcome!

Because it allows you to know where in space your hand is, where in space your face is, and where they are in relation to each other. Congratulations! If you have parietal lobe issues, you might have issues slapping yourself in the face… among other issues but those are probably not relevant.

More specifically, the parietal lobe is split up into the above sections. First you have the somatosensory cortex

(This post was brought to you by me, figuring out how to “remove background” on an image and abusing this newfound power). So with the hand slapping thing, you will feel both your hand making contact with your face, and your face being slapped, thanks to this doohickey!

The superior and supramarginal cortices are visual, so it guides your movement to, say, pick up a water bottle. And slap yourself in the face, although you can do that with your eyes closed (go ahead, try it). That’s thanks to the posterior cingulate gyrus but we will get there later because it is a LOT. For now we have the friendly, simple

Angular Gyrus, which does what it says. So thinking about your place in space, where you want to go, where you’ve been, which way is north, which way is your house. Boom. Angular Gyrus. The Angular Gyrus and the Supramarginal Gyrus together make up the inferior parietal lobule (sub-lobe)

Now on the OTHER side of the parietal cortex (cut your brain in half, saggitally, to expose this part) (don’t cut, like, YOUR brain in half… couldn’t learn much then, could you) (actually) (we won’t go there). Episodic memory retrieval=who, what, when, where, and emotions of memories.Makes sense this is with visuo-spatial imagery. When you imagine up these memories, you envision the location of these memories and where these memories took place. Self-consciousness is also related to this area (but not exclusively located here. It’s pretty well understood that’s not located in one area but processed throughout the brain. NOW for the REAL doosy

Phew. Look at that. And such a small area. It is primarily known for its role in the Dorsal Stream in visual processing. A lot of its other roles kind of relate to this, as it is also known as the “where” stream. So spacial awareness, movements in space, mental rotation (that skill on IQ tests where they give you the shape and ask you to ID the shape from another angle), mental imagery, manipulation of visual imagery. So your understanding and manipulation of space. Interestingly (possibly connected) math and reading abilities are also highly related to this area. Spatial and non-spatial working memory (temporary memory holding, decision making), response inhibition, and task switching are all related to this area. Which is interesting because they are also all related to the medial prefrontal cortex. Pathway?? (Probably, I haven’t looked into it)

Not labeled here:

Medial Parietal-Pain processing and meditation

Intraparietal Sulcus-Saccadic eye movements, attention, reaching, grasping, tactile manipulation of objects, observing hand movements, passive tool use, object matching and object size and orientation discrimination. (aka REALLY relevant for slapping yourself)

So there you have it. The overall structures and their functions within the parietal lobe! 

Is Language Different from Speech?

The idea of localization of function in the brain (where different areas are responsible for specific functions) is a reoccurring theme throughout neuroscience, but as a quick review: there’s are primary regions of the cortex, where incoming or outgoing impulses terminate such as the primary motor cortex and primary sensory cortex. In addition to primary regions there are other areas termed association areas that are for refining inputs and outputs as well as high order analysis, such as the parietal association cortex. Two of the most publicized regions in the cortex that are integral for proper language production and comprehension are Broca’s area (BA 44 and 45 the pars opercularis and pars triangularis) for language production and Wernicke’s area (posterior aspect of the superior temporal gyrus) for language comprehension. Damage to these areas produces a distinct types of aphasia, aphasia refers to disruption of language production and/or comprehension. Broca’s aphasia occurs following damage to its respective area and is characterized by the ability to comprehend what people say or write, but you cannot speak or write coherently. Wernicke’s aphasia, the mirror opposite of Broca’s, is characterized by the ability to speak coherently but you cannot understand spoken or written language. These aphasia’s clearly elucidate the distinction between speech and language as congenitally deaf individuals who communicate via gestures have analgous deficits following damage to these areas. Speech is a form of language, as the production of phonemes allow for the communication of meaning and follows a set of grammatical rules. Language, on the other hand, is the capacity to acquire a system of signs (spoken, written, gestures, symbols, braille, etc) that communicates meaning that relies on grammar. In people who are deaf from birth, following damage to Broca’s or Wernicke’s, are left with sign language aphasia, in which they can’t comprehend sign gestures anymore or have improper hand shape or position when trying to communicate.

-NS

More (Detailed) Neuroscience and Behavior Notes

Other Neuroscience and Behavior Notes (with pics!)
What’s not included in that^ post is here and vice versa. Also some things might repeat.

 

Neurons: The Basic Elements of Behavior
The Structure of the Neuron

  • Neurons: Nerve cells, the basic elements of the nervous system
  • Perhaps as many as trillion neurons throughout the body are involved in the control of behavior.
  • The nucleus incorporates heredity material that determines how a cell will function.
  • Neurons are physically held in place by glial cells. Glial cells provide nourishment to neutrons, insulate them, help repair damage, and generally support neural functioning.
  • Terminal Buttons AKA Terminal Branches
  • Myelin Sheath: made up of fat and protein
  • Neural impulses generally move across neurons in one direction only

Keep reading

  • The scientific study of suffering inevitably raises questions of causation, and with these, issues of blame and responsibility. Historically, doctors have highlighted predisposing vulnerability factors for developing PTSD, at the expense of recognizing the reality of their patients’ experiences… This search for predisposing factors probably had its origins in the need to deny that all people can be stressed beyond endurance, rather than in solid scientific data; until recently such data were simply not available… When the issue of causation becomes a legitimate area of investigation, one is inevitably confronted with issues of man’s inhumanity to man, with carelessness and callousness, with abrogation of responsibility, with manipulation and with failures to protect.
  • As the ACE study has shown, child abuse and neglect is the single most preventable cause of mental illness, the single most common cause of drug and alcohol abuse, and a significant contributor to leading causes of death such as diabetes, heart disease, cancer, stroke, and suicide. 
  • Because drugs have become so profitable, major medical journals rarely publish studies on nondrug treatments of mental health problems. Practitioners who explore treatments are typically marginalized as “alternative.” Studies of nondrug treatments are rarely funded unless they involve so-called manualized protocols, where patients and therapists go through narrowly prescribed sequences that allow little fine-tuning to individual patients’ needs. Mainstream medicine is firmly committed to a better life through chemistry, and the fact that we can actually change our own physiology and inner equilibrium by means other than drugs is rarely considered. 
  • The brain-disease model overlooks four fundamental truths: (1) our capacity to destroy one another is matched by our capacity to heal one another. Restoring relationships and community is central to restoring well-being; (2) language gives us the power to change ourselves and others by communicating our experiences, helping us to define what we know, and finding a common sense of meaning; (3) we have the ability to regulate our own physiology, including some of the so-called involuntary functions of the body and brain, through such basic activities as breathing, moving, and touching; and (4) we can change social conditions to create environments in which children and adults can feel safe and where they can thrive. 
  • The contrast with the scans of the eighteen chronic PTSD patients with severe early-life trauma was startling. There was almost no activation of any of the self-sensing areas of the brain: The MPFC, the anterior cingulate, the parietal cortex, and the insula did not light up at all; the only area that showed a slight activation was the posterior cingulate, which is responsible for basic orientation in space. There could be only one explanation for such results: In response to the trauma itself, and in coping with the dread that persisted long afterward, these patients had learned to shut down the brain areas that transmit the visceral feelings and emotions that accompany and define terror. Yet in everyday life, those same brain areas are responsible for registering the entire range of emotions and sensations that form the foundation of our self-awareness, our sense of who we are. What we witnessed here was a tragic adaptation: In an effort to shut off terrifying sensations, they also deadened their capacity to feel fully alive. 
  • Traumatized people chronically feel unsafe inside their bodies: The past is alive in the form of gnawing interior discomfort. Their bodies are constantly bombarded by visceral warning signs, and, in an attempt to control these processes, they often become expert at ignoring their gut feelings and in numbing awareness of what is played out inside. They learn to hide from their selves. 
  • The more you stay focused on your breathing, the more you will benefit, particularly if you pay attention until the very end of the out breath and then wait a moment before you inhale again. As you continue to breathe and notice the air moving in and out of your lungs you may think about the role that oxygen plays in nourishing your body and bathing your tissues with the energy you need to feel alive and engaged. 


― Bessel A. van der Kolk, Traumatic Stress: The Effects of Overwhelming Experience on Mind, Body, and Society

Method of recording brain activity could lead to mind-reading devices

A brain region activated when people are asked to perform mathematical calculations in an experimental setting is similarly activated when they use numbers — or even imprecise quantitative terms, such as “more than”— in everyday conversation, according to a study by Stanford University School of Medicine scientists.

Using a novel method, the researchers collected the first solid evidence that the pattern of brain activity seen in someone performing a mathematical exercise under experimentally controlled conditions is very similar to that observed when the person engages in quantitative thought in the course of daily life.

“We’re now able to eavesdrop on the brain in real life,” said Josef Parvizi, MD, PhD, associate professor of neurology and neurological sciences and director of Stanford’s Human Intracranial Cognitive Electrophysiology Program. Parvizi is the senior author of the study, published Oct. 15 in Nature Communications. The study’s lead authors are postdoctoral scholar Mohammad Dastjerdi, MD, PhD, and graduate student Muge Ozker.

The finding could lead to “mind-reading” applications that, for example, would allow a patient who is rendered mute by a stroke to communicate via passive thinking. Conceivably, it could also lead to more dystopian outcomes: chip implants that spy on or even control people’s thoughts.

“This is exciting, and a little scary,” said Henry Greely, JD, the Deane F. and Kate Edelman Johnson Professor of Law and steering committee chair of the Stanford Center for Biomedical Ethics, who played no role in the study but is familiar with its contents and described himself as “very impressed” by the findings. “It demonstrates, first, that we can see when someone’s dealing with numbers and, second, that we may conceivably someday be able to manipulate the brain to affect how someone deals with numbers.”

The researchers monitored electrical activity in a region of the brain called the intraparietal sulcus, known to be important in attention and eye and hand motion. Previous studies have hinted that some nerve-cell clusters in this area are also involved in numerosity, the mathematical equivalent of literacy.

However, the techniques that previous studies have used, such as functional magnetic resonance imaging, are limited in their ability to study brain activity in real-life settings and to pinpoint the precise timing of nerve cells’ firing patterns. These studies have focused on testing just one specific function in one specific brain region, and have tried to eliminate or otherwise account for every possible confounding factor. In addition, the experimental subjects would have to lie more or less motionless inside a dark, tubular chamber whose silence would be punctuated by constant, loud, mechanical, banging noises while images flashed on a computer screen.

“This is not real life,” said Parvizi. “You’re not in your room, having a cup of tea and experiencing life’s events spontaneously.” A profoundly important question, he said, is: “How does a population of nerve cells that has been shown experimentally to be important in a particular function work in real life?”

His team’s method, called intracranial recording, provided exquisite anatomical and temporal precision and allowed the scientists to monitor brain activity when people were immersed in real-life situations. Parvizi and his associates tapped into the brains of three volunteers who were being evaluated for possible surgical treatment of their recurring, drug-resistant epileptic seizures.

The procedure involves temporarily removing a portion of a patient’s skull and positioning packets of electrodes against the exposed brain surface. For up to a week, patients remain hooked up to the monitoring apparatus while the electrodes pick up electrical activity within the brain. This monitoring continues uninterrupted for patients’ entire hospital stay, capturing their inevitable repeated seizures and enabling neurologists to determine the exact spot in each patient’s brain where the seizures are originating.

During this whole time, patients remain tethered to the monitoring apparatus and mostly confined to their beds. But otherwise, except for the typical intrusions of a hospital setting, they are comfortable, free of pain and free to eat, drink, think, talk to friends and family in person or on the phone, or watch videos.

The electrodes implanted in patients’ heads are like wiretaps, each eavesdropping on a population of several hundred thousand nerve cells and reporting back to a computer.

In the study, participants’ actions were also monitored by video cameras throughout their stay. This allowed the researchers later to correlate patients’ voluntary activities in a real-life setting with nerve-cell behavior in the monitored brain region.

As part of the study, volunteers answered true/false questions that popped up on a laptop screen, one after another. Some questions required calculation — for instance, is it true or false that 2+4=5? — while others demanded what scientists call episodic memory — true or false: I had coffee at breakfast this morning. In other instances, patients were simply asked to stare at the crosshairs at the center of an otherwise blank screen to capture the brain’s so-called “resting state.”

Consistent with other studies, Parvizi’s team found that electrical activity in a particular group of nerve cells in the intraparietal sulcus spiked when, and only when, volunteers were performing calculations.

Afterward, Parvizi and his colleagues analyzed each volunteer’s daily electrode record, identified many spikes in intraparietal-sulcus activity that occurred outside experimental settings, and turned to the recorded video footage to see exactly what the volunteer had been doing when such spikes occurred.

They found that when a patient mentioned a number — or even a quantitative reference, such as “some more,” “many” or “bigger than the other one” — there was a spike of electrical activity in the same nerve-cell population of the intraparietal sulcus that was activated when the patient was doing calculations under experimental conditions.

That was an unexpected finding. “We found that this region is activated not only when reading numbers or thinking about them, but also when patients were referring more obliquely to quantities,” said Parvizi.

“These nerve cells are not firing chaotically,” he said. “They’re very specialized, active only when the subject starts thinking about numbers. When the subject is reminiscing, laughing or talking, they’re not activated.” Thus, it was possible to know, simply by consulting the electronic record of participants’ brain activity, whether they were engaged in quantitative thought during nonexperimental conditions.

Any fears of impending mind control are, at a minimum, premature, said Greely. “Practically speaking, it’s not the simplest thing in the world to go around implanting electrodes in people’s brains. It will not be done tomorrow, or easily, or surreptitiously.”

Parvizi agreed. “We’re still in early days with this,” he said. “If this is a baseball game, we’re not even in the first inning. We just got a ticket to enter the stadium.”