Wednesday, August 17, 2022

What Part Of The Brain Is Responsible For Smell

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Memory Of Felt Emotion

Headaches, loss of smell part of COVIDâs impact on brain

Many researchers use self-report measures of felt emotion as a manipulation check. This raises an interesting question and a possible methodological weakness: are people always accurate when they recall how they felt in the past? Several findings suggest this is not the case. For instance, in a study of memory for emotions in supporters of former U.S. presidential candidate Ross Perot, supporters were asked to describe their initial emotional reactions after Perot’s unexpected withdrawal in July 1992 and again after the presidential election that November.

Between the two assessment periods, the views of many supporters changed dramatically as Perot re-entered the race in October and received nearly a fifth of the popular vote. The results showed that supporters recalled their past emotions as having been more consistent with their current appraisals of Perot than they actually were.

Another study found that people’s memories for how distressed they felt when they learned of the 9/11 terrorist attacks changed over time and moreover, were predicted by their current appraisals of the impact of the attacks . It appears that memories of past emotional responses are not always accurate, and can even be partially reconstructed based on their current appraisal of events.

Recent Exploratory Research On Novel Stress Marker Candidates

Cortisol, -amylase, chromogranin A, etc. have been established as stress markers, as mentioned above. Although these factors are effective for an evaluation of acute stress in healthy subjects, it is not suitable for the purpose of grasping changes in brain function due to chronic stress. In addition, many studies conducted around the world aim to find novel biomarkers of disorders, contributing to post-onset diagnostic methods. The authors have loaded various types of stress on experimental animals and they have found a group of new stress marker candidates in the brain. We have mainly studied developmental disorders due to chemical stress , schizophrenia , and chronic alcoholism . As for chemical stress, we have been studying the effects of environmental chemical substances and the effects of radiation as physical stress . Furthermore, the effects of restraint, disturbance of the light-dark cycle, and water immersion were investigated in order to clarify the process from stress to the onset of depression.

Retailers Use Scent To Draw Shoppers In

Retailers capitalize on the contextual connection between smell and place to draw people into their stores.

ScentAir, a marketing firm that designs signature scents for businesses in more than 100 countries, said many of its retail clients switch to holiday aromas this time of year.

As an example, let me take one of the very popular holiday scents that we use called holiday spice, said ScentAir CEO Andy Kindfuller.

The scent incorporates notes of pine needles, cinnamon, berries and orange. With it, and other holiday scents, Kindfuller said retailers aim to create new memories of shopping to draw people back to brick-and-mortar stores in an age of online retail.

The scent also brings shopper back to happy holiday memories of the past.

It brings back to the consumer memories that they have, maybe from their childhood where they were around pine needles or were eating oranges and berries at the holiday time, and those memories come back to them and again makes them feel better about that retailer, Kindfuller said.

One client, a major clothing retailer, started using a woodsy pine scent in early November to remind people to start their Christmas shopping.

Scent memories are fragile, though. Over-exposure can reduce the emotional punch, which is why not many people have powerful holiday memories associated with common smells, like coffee. And why Lou McCall, who sells trees at Philadelphias Christmas Village, doesnt think Christmas anymore when he smells evergreens.

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How Does Our Sense Of Smell Work

The process through which molecules in the air are converted by our brain into what we interpret as smells and the mechanisms our brain uses to categorize and interpret those odors is, as you have probably guessed, a complicated one. In fact, the process is so complicated that the Nobel Prize in Physiology or Medicine was awarded in 2004 to the researchers Richard Axel and Linda Buck for their work in decoding it.

When we come into contact with an odor, or molecules from volatile substances drifting through the air, the neurons that make up your olfactory receptor cells send a signal to a part of your brain called the olfactory bulb. Axel and Buck found roughly 1,000 genes played a role in coding for different types of olfactory receptors, each of which focus on a small subset of odors. Thus each receptor is not responsible for understanding all possible smells. Those signals are then passed to what are called microregions within the olfactory bulb where again, different microregions specialize in different odors. The olfactory bulb is then responsible for interpreting those signals into what we perceive as smells.

So many of these odor-driven memories may further be childhood memories because those years are when we experience most smells for the first time. There is not yet research to suggest that we can tap into the link between scents and memory to help us cram for tests or remember where we put our car keys as adults.

How Do Our Brains Keep Smells Organized

Structure and functions of brain

12:12 minutes

How we smell has been a bit of a mystery to scientists. Other senses are easier to understand: For example, its possible to predict what a color will look like based on its wavelength. But predicting what a new molecule will smell like is more difficult.

Our sense of smell can be quite complex. Take the delicious smell of morning coffeethat aroma is made up of more than 800 individual molecules.

How does our brain keep track of the millions of scents that we sniff? To find out, a group of scientists gave mice different molecules to smell, and tracked what patterns were formed in their brains. Their results were recently in the journal Nature.

Neurobiologist Robert Datta, one of the authors on that study, joins Ira to discuss how our brains make patterns every time we sniff, and how wine aficionados train their noses to decode the different scents in wine.

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Anatomy Of The Olfactory System

Odorant contact with the primary olfactory neurons is the starting point of olfactory transduction. The glomerulus of the olfactory bulb is the only relay between the peripheral and central olfactory system. Olfactory information is conducted to the secondary olfactory structures, notably the piriform cortex. The tertiary olfactory structures are the thalamus, hypothalamus, amygdala, hippocampus, orbitofrontal cortex and insular cortex.

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The Senses: Smell And Taste

Smell and taste are the oldest of the senses. They are essential for survival, having evolved to play key roles in such basic processes as feeding, mating, and avoiding danger.

As the two chemical senses, they work by allowing tiny bitsmoleculesof the outside world into the body, and binding to them.

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What Part Of The Brain Controls Anger

Much like fear, anger is a response to threats or stressors in your environment. When youre in a situation that seems dangerous and you cant escape, youll likely respond with anger or aggression. You can think of the anger response and the fight as part of the fight-or-flight response.

Frustration, such as facing roadblocks while trying to achieve a goal, can also trigger the anger response.

Anger starts with the amygdala stimulating the hypothalamus, much like in the fear response. In addition, parts of the prefrontal cortex may also play a role in anger. People with damage to this area often have trouble controlling their emotions, especially anger and aggression.

Parts of the prefrontal cortex of the brain may also contribute to the regulation of an anger response. People with damage to this area of the brain sometimes

Recent Studies On The Effects Of Aroma On Biochemical Parameters In The Brain

New study reveals ‘significant’ effects of COVID-19 infection on the brain | Newshub

As described above, the effect of aroma on the stress response in the brain has not been well documented yet. The authors focused on the stress-suppressing effect of certain aroma in the process of analyzing the effect of stress on the brain. Conventionally, it is empirically recognized that a certain aroma has a stress-suppressing effect, although its effectiveness has not been fully proven . To attempt a proof of the effect of aroma, we examined, in experimental animals, some kinds of smell by means of behavioral analysis and measuring biochemical parameters that have recently been identified as potential stress marker candidates in the brain and blood. Here, we would like to introduce our recent studies on the effects of aroma of coffee beans, lavender, cypress, -pinene, and thyme linalool.

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Seeing Left Smelling Right

Fortunately, all of these neural conspiracy theories have been largelydebunked.However, the fact does remain that we do have two hemispheres that areconnected but divided a cortical separate but equal,” if you will. And oftentimes, one ofthese hemispheres is larger than the other, the smaller being situated slightlybehind. Now, again, this is not to say that the bigger hemisphere isbetter, simply that they are asymmetric, and presumably this asymmetry hasevolved for a reason.

Researchers from University College London have investigatedthe purpose of this neural asymmetry on a much smaller scale using the zebrafish,a common animal model used for investigating basic but deceptively complex brain-relatedphenomena thanks to their simplified central nervous system. Published in thejournal CurrentBiology, the researchers discovered that neuronal asymmetry lendsitself towards enhanced processing of sensory information in the zebrafish, and that asymmetrical brain can result in an impairment of the processing of visual orolfactory stimuli.

The real test of any scientific phenomenon though, is whathappens when you disrupt this process . Will the other hemisphere take over, or willthat function be entirely lost?


Yet another instance of science proving cool stuffthat, if we really thought about it, we already kind of figured to be true.

Image Credit: Nobuyuki Kayahara, Gray’s Anatomy and Azul

Smells Like Teen Spirit

When you see, hear, touch, or taste something, that sensory information first heads to the thalamus, which acts as your brain’s relay station. The thalamus then sends that information to the relevant brain areas, including the hippocampus, which is responsible for memory, and the amygdala, which does the emotional processing.

But with smells, it’s different. Scents bypass the thalamus and go straight to the brain’s smell center, known as the olfactory bulb. The olfactory bulb is directly connected to the amygdala and hippocampus, which might explain why the smell of something can so immediately trigger a detailed memory or even intense emotion.

But why, if we’re such visual creatures, does smell get this elevated status in our brains? Some think it goes back to the way we evolved: Smell is one of the most rudimentary senses with roots in the way single-celled organisms interact with the chemicals around them, so it has the longest evolutionary history. This also might explain why we have at least 1,000 different types of smell receptors but only four types of light sensors and about four types of receptors for touch.

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A Matter Of Proximity

Another reason odors seem to be so tightly associated with emotional memories is due to brain structure.

This olfactory area that processes the information is very close proximity to a part of the brain that processes emotional information, and in particular emotional memories: the limbic system and the hippocampus and the amygdala, Dalton said.

These structures are nestled near the center of the brain, and they developed together in our evolutionary ancestors. Dalton said smell was designed to immediately send an emotional signal: good or bad, approach or retreat, eat or avoid.

Why Do Smells Trigger Memories

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Your sense of smell may be a better memory trigger than your sense of sight. Here’s why a whiff of apple pie may instantly transport you home in your mind

Whenever I smell the pages of a brand new book, I am reminded of all the late night reading I did as a kid. I can even feel the soft fabric on the arms of my favorite reading chair and sense the quiet of a house where everyone else is asleep. The stresses of the day start to give way a bit to feelings of calm and focus. We have an armchair in my daughters room very similar to my childhood reading chair, but sitting in it doesnt quite conjure up those memories as effectively as that new book smell.

And I am not alone! Anecdotally, many of us have had experiences where a certain smellperhaps chlorine, fresh baked cookies, or the salty beach airfloods our brain with memories of a distinct event or location that we associate clearly with certain emotions.

There have also been scientific studies using a variety of approaches to back up this anecdotal evidence. One of the first was a study led by Dr. Rachel Herz at Brown University in 2004. Herz and her collaborators found that a group of five women showed more brain activity when smelling a perfume with which they associated a positive memory than when smelling a control perfume they had never before smelled. The brain activity associated with the memorable perfume was also greater than that produced by the visual cue of seeing the bottle of perfume.

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How Does Loss Of Smell And Taste Affect Your Appetite

  • The smell of food triggers the appetite loss of smell can lead to reduced appetite and lack of interest in food.
  • Loss of smell can reduce saliva production. This makes dry foods, like biscuits and crackers, harder to eat.
  • Many foods that are needed for a balanced diet may no longer be appealing this can lead to a diet that doesnt have a balanced variety of nutrients.
  • Changes in taste may make some foods, such as meat, taste bad and make you avoid those foods.
  • Any of these problems may affect what food you choose and lead to a poor diet.

Emotional Memory And Sleep

Emotional memory and sleep has been a well-researched association. Emotional memories are consolidated greater during sleep, rather than neutral memories. Studies have investigated high valence and arousing words, in comparison to neutral words. Sleep enhances the consolidation of the high valence and arousing words and therefore these are remembered more post-sleep. This concept has been demonstrated in many studies using a variety of media such as pictures, film clips, and words.

Memories of ‘future relevance’ are also consolidated greater during sleep. In a study by Wilhelm et al., 2011, memories of items that participants knew were needed for the future were remembered more after sleep. Sleep consolidated these memories of future relevance to a greater extent. Memories that are emotionally significant and relevant for the future are therefore preferentially consolidated during sleep. This can translate to mean that memories that are more meaningful or valuable to a person are consolidated more.

The concept of emotional memory and sleep can be applied to real-life situations e.g. by developing more effective learning strategies. One could integrate the memorization of information that possesses high emotional significance with information that holds little emotional significance , prior to a period of sleep.

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Loss Of Taste And Smell After Head Injury: Key Points

Loss of taste and smell after head injury can have a serious impact on a persons quality of life. It typically occurs after damage to the parts of the brain in charge of smell, such as the olfactory regions.

While there are currently no proven treatments for anosmia caused by head trauma, olfactory training may prove useful. Its also a good idea to talk to your doctor about your symptoms as soon as you notice them. New treatments for anosmia are on the rise, and your doctor might know of some that could help you.

What Happens When Taste Reaches The Brain

How the Brain Perceives Taste

In general, our understanding of taste is inferior to our knowledge of the other human senses. Understanding and describing our sensory perception of food requires knowing what mechanisms lie beyond the taste buds.

Taste stimulants in the mouth activate specific receptors on the tongue corresponding to each of the basic flavors: sweet, salty, sour, bitter, salty and the newly discovered umami.

The signal is then translated into the brain, but there is still much ignorance about how the peripheral signal is used by the central nervous system to encode flavor quality.

A team of researchers from the German Institute for Human Nutrition in Potsdam and the Charité University Hospital in Berlin, in Germany, are working on this, and they have revealed how taste is encoded in the patterns of neural activity in the human brain.

The sense of taste is crucial for the choice of food and the formation of food preferences. Alterations in the perception of taste or the hedonic experience of taste can cause abnormal eating behavior and can lead to failure or excess nutrition said lead research expert Kathrin Ohla.

Our research aims to expand the knowledge of the neural mechanisms of taste perception and evaluation. This knowledge is essential for the development of strategies to moderate abnormal eating behavior, adds this researcher, whose work is published in Current Biology .

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The Sense Of Taste Is In The Brain And Not In The Tongue

The world is an illusion , since at no time can we come into contact with reality if it is not through the interpretations made by the nervous system.

Some of these sensations seem to be more fixed and to be programmed in the genes or in the bodys organization , while others seem be more flexible and change as the brain learns .

In relation to the sense of taste, it is often thought that the taste buds are responsible for detecting the five flavors of food and sending that information to the brain.

But now, a group of researchers from Columbia University Medical Center, has published an article in the journal Nature in which they show that a mouse can be caused to perceive that water is sweet or bitter just by modifying a group of neurons in the body.

The most important thing about this study is the discovery that it is possible to recreate an animals taste perception and the internal representation of sweet and sour tastes, by directly manipulating the brain, explained Charles S. Zuker, director of the study and investigator of the Howard Hughes Medical Institute.

That is why, in his opinion, the taste, as we know it, is ultimately in the brain, not in the tongue.

This, put another way, means that the tongue may have receptors to pick up bitter and sweet taste, but it is in the brain that those signals make sense.

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