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Summary: Perception and working memory are more deeply entangled than previously believed.

Source: George Washington University

Many people have an intuitive, though incorrect, understanding of how the brain works: Our senses perceive objectively factual data, and our higher-level thought processes interpret that data, pull some levers and shape our conclusions and behavior accordingly.

But perception and thought are fundamentally linked, according to research published in Nature Human Behavior last week by Dwight Kravitz, an assistant professor of cognitive neuroscience at the George Washington University.

“We create a false separation between our perception of the world and the way that we’re thinking about it,” Dr. Kravitz said. “But actually these two things occur at the same time, in the same place, and as a result, they interfere with each other. What you’re holding in mind changes what you see, and what you see changes what you’re holding in mind.”

Existing literature has established that perception and visual working memory (VWM), the ability to temporarily maintain and manipulate information, take place in the same parts of the brain. But “Visual Working Memory Directly Alters Perception,” written with postdoctoral student Chunyue Teng in the Columbian College of Arts and Sciences Department of Psychology, demonstrates the behavioral consequences of that proximity.

The study’s three experiments involved holding a visual stimulus in mind—either a color or a line tilted to a specific orientation—and then introducing a new color or orientation as a distractor during a distinct task. When the distractor was similar to the maintained content, it biased visual reports toward itself.

In the third experiment, which Dr. Kravitz called “the least purely academic,” subjects were asked to distinguish between two colors or orientations while holding in mind a third. When the maintained information fell between the two stimuli, subjects rated them as more similar; when it fell outside, subjects were more likely to differentiate them.

This shows a train in different colors

Holding a color in mind affects the perceived color of an image. Image is credited to Dwight Kravitz.

A subject might be asked to hold a shade of rose pink in their mind, for instance, and then be shown two more shades—one greener than the maintained shade, the other pinker. The subjects were likely to be able to differentiate between the new colors. If both introduced shades were greener (or pinker) than the rose-pink the subject was thinking about, however, the subject was less able to tell them apart.

“The human system is nothing like a camera,” Dr. Kravitz said. “The way you’re thinking about the world changes not just the way things are emphasized, but also your baseline perceptions. The actual content of the world shifts slightly in reference to the things you’re holding in mind.”

Dr. Kravitz said further research could have major implications about the way the stereotypes we hold in mind affect our perception.

“To find effects here, on this really basic level of visual perception, means that if you move up to more complicated judgments—trustworthiness of faces, the likelihood of particular things happening—they’re likely going to show similar, if not larger, effects,” Dr. Kravitz said. “The things that you’re holding in mind and the biases that you bring are going to change what you see and how you act.”

Source:
George Washington University
Media Contacts: 
Ruth Steinhardt – George Washington University
Image Source:
The image is credited to Dwight Kravitz.

Original Research: Closed access
“Visual working memory directly alters perception”. Chunyue Teng & Dwight J. Kravitz.
Nature Human Behavior. doi:10.1038/s41562-019-0640-4

Abstract

Visual working memory directly alters perception

Visual working memory (VWM), the ability to temporarily maintain and manipulate information, underlies a variety of critical high-level behaviours from directing attention to making complex decisions5. Here we show that its impact extends to even the most basic levels of perceptual processing, directly interacting with and even distorting the physical appearance of visual features. This interference results from and can be predicted by the recruitment of posterior perceptual cortices to maintain information in VWM, which causes an overlap with the neuronal populations supporting perceptual processing. Across three sets of experiments, we demonstrated bidirectional interference between VWM and low-level perception. Specifically, for both maintained colours and orientations, presenting a distractor created bias in VWM representation depending on the similarity between incoming and maintained information, consistent with the known tuning curves for these features. Moreover, holding an item in mind directly altered the appearance of new stimuli, demonstrated by changes in psychophysical discrimination thresholds. Thus, as a consequence of sharing the early visual cortices, what you see and what you are holding in mind are intertwined at even the most fundamental stages of processing.

Source: https://neurosciencenews.com/perception-working-memory-14514/


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  • People often don’t even realise they are in an abusive relationship.
  • It can be hard for others to understand why someone stays with an abusive partner.
  • It’s often because of something called “trauma bonding,” where you become addicted to the hormonal rollercoaster an abuser sends you on.

Those who have never been in an abusive relationship struggle to understand how people remain in one for so long. If somebody was mistreating you, “why did you stick around?” they ask.

For survivors, this can be a really tough question to answer. The lucky ones escape, and stumble upon articles or books that give them the terms to be able to understand what happened to them, and thus describe their experience. Other times, though, this doesn’t happen, and people might not even be aware they were in a relationship that could be classed as “abusive.”

This is because we are conditioned to believe abuse is always physical. On TV and in films, we see characters who are obviously evil. They are violent to their partners, shout at them aggressively, or even murder them in a fit of rage. While this does happen, it’s not a true representation of the abuse many others experience.

According to therapist Shannon Thomas, author of “ Healing from Hidden Abuse,” psychological abuse is insidious, and it occurs a over time like an IV drip of poison entering your veins.

It starts with an off-hand comment here, or an insult there, but often victims brush these moments off. This is because abusive people are great at pretending to be everything you’re looking for in a partner, and they love bomb you with affection. Victims tend to believe this is the abuser’s real self, and when the mask starts to slip more and more, they believe its “out of character” and it must be their own fault for making their partner angry.

People stay in these relationships partly because they are trying to win back the abuser’s affection. However, Thomas told Business Insider that victims also become biologically attached to their abusers through something called “trauma bonding.”

It’s like an addictive drug.

It’s a bit like becoming addicted to a drug. A psychologically abusive relationship is a rollercoaster, with punishment and then intermittent reinforcement of kindness when you “behave.” This means the body is going through its own turmoil, with high levels of the stress hormone cortisol, paired with dopamine when given affection as a reward.

“You have this back and forth, and the body becomes addicted,” Thomas said. “When we’re looking for something that we want, that we once had, which is a connection with somebody, and they are playing cat and mouse where they are pulling it back and forth, then the body really does become dependent on having that approval.”

This hormonal rollercoaster really takes its toll on someone’s body. Victims might find they break out in acne, even though they’ve always had good skin. They might have chest pains. Thomas has said that in her practise she has even seen her clients develop autoimmune disorders.

“Their bodies start to shut down, and they start really struggling with chronic pain, migraines, and some arthritic type pains and conditions, and they just can’t fight infections as well,” she said. “The body really can only take so much stress.”

Victims stay in these relationships despite of the stress on their bodies, because often it isn’t clear to them what the problems really are. Through gaslighting, control, and intermittent love, the abuser has their partner backed into a corner of self-blame and desperation of trying to win back the affection of the person they love.

Unfortunately, for many people, when they try to leave these relationships they are so bonded to their abuser that they return. Others don’t try to leave at all, and are only freed from the clutches of the abuse when they are discarded.

An abusive relationship with a narcissist or psychopath tends to follow the same pattern: idealization, devaluation, and discarding. At some point, the victim will be so broken, the abuser will no longer get any benefit from using them. They may have totally bankrupted them, or destroyed their confidence, or worse, and they move on to their next target.

However, once they are gone, the victim — or survivor as Thomas calls them at this point — can finally start coming round to the idea they were abused. They can grieve, and finally see the damage that was being done, and realise it wasn’t their fault.

That’s when the healing can really begin, Thomas says, and the survivor can realise that they were targeted not because they were weak, but because they had so much to give.

These are the signs you might be in a trauma bond with someone, according to Psych Central:

  • A constant pattern of nonperformance — your partner promises you things, but keeps behaving to the contrary.
  • Others are disturbed by something that is said or done to you in your relationship, but you brush it off.
  • You feel stuck in the relationship because you see no way out.
  • You keep having the same fights with your partner that go round in circles with no real winner.
  • You’re punished or given the silent treatment by your partner when you say or do something “wrong.”
  • You feel unable to detach from your relationship even though you don’t truly trust or even like the person you’re in it with.
  • When you try and leave, you are plagued by such longing to get back with your partner you feel it might destroy you.

Source: https://www.businessinsider.com/trauma-bonding-explains-why-people-often-stay-in-abusive-relationships-2017-8?utm_content=buffer77905&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer-bi

Approximately 5.8 million Americans are living with Alzheimer’s today, and though the root cause of the disease is largely unknown, we suspect that genetics and lifestyle both play a roleA new studyout of Massachusetts General Hospital provides some fresh clues on how we can protect ourselves from this aggressive form of dementia.

By studying the routines of 182 older adults in a clinical setting, the researchers found that those who kept up with physical activity were less likely to experience cognitive decline. This isn’t altogether surprising, considering the World Health Organization already recommends regular exercise as a preventive measure against Alzheimer’s. What is new information, though, is the amount of exercise that proved beneficial (8,900 steps a day seemed to be enough to do the trick) and the exact way that this movement affected the brain.

The study’s authors found that physical activity reduced the amount of b-amyloid (Ab), a protein fragment that seems to accumulate in the brain during the early stages of Alzheimer’s, before physical symptoms present themselves. This is the first study to find that exercise might have a beneficial impact during this early, “pre-clinical” stage of Alzheimer’s. It’s good news because it shows that doctors may one day be able to put holistic treatment plans in place at the first sign of disease. 

Jasmeer Chhatwal, M.D., Ph.D., a corresponding author of the study, cites this as yet another reason everyone—regardless of age or predisposition to Alzheimer’s—should make exercise a priority.

“One of the most striking findings from our study was that greater physical activity not only appeared to have positive effects on slowing cognitive decline, but also on slowing the rate of brain tissue loss over time in normal people who had high levels of amyloid plaque in the brain,” he writes.

The team at Massachusetts General Hospital is now busy zeroing in on the exact type and duration of exercise that’s most beneficial in reducing b-amyloid in the brain. Previous research has found that strong legs in particular contribute to a more robust hippocampus, the part of the brain that processes memories, so it’ll be interesting to see if their findings come out in favor of leg day too.

In the meantime, we can all practice other brain-healthy practices like getting quality sleep and eating a diet rich in dark, leafy greens, whole grains, and plenty of fermented foods.

Source: https://www.mindbodygreen.com/articles/how-exercise-might-prevent-alzheimers-according-to-a-new-study?otm_medium=onespot&otm_source=inbox&otm_campaign=Daily+Mailer&otm_content=daily_20190718&otm_click_id=a210229f455f48815644d245ee72a45f&os_ehash=4366f4a34c67ce527584ae17c656bb4bd17ce861

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