4.4: Smell and Taste: The Sensual Senses

The Tone-Based Organization of the neurons fire at their highest rate, which is slightly out of sync with Basilar Membrane, according to volley theory.

Hair cells at the top of the basilar are more sensitive to low-pitched tones than high-pitched ones.

We respond differently to pleasant and unpleasant sounds.

One study found that music that made people feel "chills" or "Shivers" boosted activity in the same brain regions associated with euphoria.
"sex," "drugs," and "rock and roll" often go together.

The place theory and the frequency theory of sound perception are related.

20,000 hertz terms of how we perceive sounds.

About one in 1,000 people have a profound loss of hearing.

Roughly 15 percent of Americans have hearing problems in one or both ears.

There are many causes of deafness, some of which are genetic, others from disease, injury, or exposure to loud noise.

"Turn down the sound on your iPod, or you'll go deafness by the time you're my age" is a ring of truth that your grandmother warns you to ignore.

Tinnitus, a ringing, roaring, hissing, or buzzing sound in the ears, can be caused by this type of hearing loss.

Hearing loss can be caused by exposure to loud noises.

Even if we've never attended a rock concert without earplugs, we lose some hearing ability as we age because of the loss of sensory cells.

Understand how we sense odors and tastes.

Many of our experiences would be dull without smell and taste.
Cuisines of the world are known for their characteristic spices.
Our senses are stimulated by smell and taste.

Our sense of smell helps us to like some foods and dislike others.

Tracking prey, establishing territo ries, and recognizing the opposite sex are some of the things that animals use their sense of smell for.

Humans are not the most smell oriented creatures.
Police use trained dogs rather than people to sniff for bombs because the average dog is 100,000 times more sensitive to smell than we are.

Researchers discovered that trained dogs, commonly Labrador retrievers, appeared to use their superior sense of smell to identify people with cancer of the lung, bladder, skin, and colon by detecting odors from organic compounds.

An alternative explanation for positive Ruling Out Rival Hypotheses findings is that dogs subconsciously signal correct responses based on their beliefs, even after extensive training.

The question of whether our "best friends" can detect cancer will continue to be pursued by researchers.

Sampling our food before swallowing is the most important function of our chemical senses.

Few of us can ignore the smell and taste of sour milk.
It's possible that a bitter taste in our food is a sign of danger.
We base our food preferences on a combination of smell and taste.
A study of young French women found that only those who already liked red meat responded favorably to pictures of it.
We like the smell and taste of things.

What we think is delicious or disgusting is shaped by culture.

The prospect of eating sacred cow meat, as in a hamburger, would be as off-putting to Hindus as eating fried tarantulas, a delicacy in Cambodia, or Casu Marzu, a Sardinian cheese filled with insect larvae, would be to most Americans.
American meat lovers and vegan people have vastly different food choices.
Modeling of eating behaviors, parental approval of food choices, and availability of foods are some of the ways in which we can acquire food preferences.

There are chemicals in the air that interact with the lining of the nose.

Not everything has an odor.
Clean water has no smell or taste.
Some animals don't smell airborne.
The star-nosed mole's snout is shaped like a star and it can detect odors underwater.
The air bubbles that the animal blows out are used to find food underwater and underground.

We can only detect a few tastes.

Figure 4.17 How We detect taste is one of the things we're sensitive to.

There is evidence for a sixth information to the brain through taste, one for fat foods.

There are more than 1,000 olfactory genes, 347 of which code for olfactory receptors.

Each olfactory neuron has a single type of olfactoryreceptor, which "recognizes" an odorant on the basis of its shape.
The lock-and-key concept is similar to how neurotransmitters bind.
Action potentials in olfactory neurons are triggered when olfactoryreceptors come into contact with odor molecule.

Put a small amount of salt on the tip of your tongue.

Put a small amount of sugar on the back of your tongue.
Good fiction is more likely than fact.

The tip of the tongue and the sides of the tongue have different types of receptors, but there's a good mix on the tongue.

The sweet flavor of dried seaweed is found in many Japanese foods.

There was one thing that all of these molecules had in common: They all contained a lot of the neurotransmitter glutamate.
The fifth taste is considered by most scientists.

Fat does something to our tongues.

Richard and his associates found that putting fat on people's tongues affects their blood levels of fat.
As soon as fat enters our mouths it affects our bodies' metabolism.
Researchers thought the responses to Ruling Out Rival Hypotheses were triggered by fat.
When they showed that smelling fat didn't change blood levels of fat, they ruled out this hypothesis.

Our sense of smell is the reason why we find food less appetizing when we are cold.

We find certain foods "delicious" because of their smell.

If you don't like it, try another exercise.
Open the identify the supertaster bag and close your eyes so you can't see which color you're picking.
You can pop a jellybean into your mouth by pinching your nose.

Our tongues have different number of taste buds.

If you find broccoli, coffee, and dark chocolate to be bitter, you're a supertaster.

It is thought that taste buds are most likely to be in the lowest 10 percent of height because of their sensitivity to bitter tastes.

Supertasters, who are overrepresented among women and people of African or Asian descent, are sensitive to oral pain and avoid bitter tastes as a result.

They don't like bitter tastes in alcohol and tobacco, which may make them healthier than the rest of us.

Two photographs show the tongues of two people, one a supertaster and one a non-supertaster.

Supertasters have more taste buds on their tongues than we realize, which makes them more sensitive to smell and taste.

Babies and siblings can smell each other's odors.

Women can tell if a person just watched a happy or sad movie from the sample of their armpit odor.

There is convergence for smell and taste in the region of the frontal cortex.

We look at the intensity of smell to see if it's pleasing.

The lim bic system helps us to distinguish between pleasant and disgusting smells.
It can be pleasant or disgusting.
The gustatory cortex is activated by both tasting and viewing disgust.
Damage to the gustatory cortex doesn't make people feel disgust.
The results show the strong links between smell, taste, and emotion.

Depression and anxiety can affect taste perception.

The same chemical messengers whose activity is enhanced by antidepressants make us more sensitive to tastes.
The researchers found that participants were more sensitive to various combinations of sweet, sour, and bitter tastes.
Depression is a frequent symptom of appetite loss.

Sexual behavior is influenced by smell.

Mice with a genetic defect in smell don't bother to mate.
Many perfume and cologne manufacturers think so.
The social signal to members of one's 2001 shows that odorless chemical that serves as a rodents respond to pheromones.
Most mammals, including whales and horses, do the same.
Most mammals have a smell and taste.

The vomeronasal organ doesn't develop in humans, so it's possible that humans are sensitive to pheromones.

Humans can detect pheromones via a different route.

We should be careful about spending large chunks of our salaries on products that promise to stir up romance.

Scientific evidence shows they probably won't work.
It's not easy to transfer a pheromone from one person to another during a passionate kiss, and it's not easy to send them across a restaurant table.
There is more to human romance than physical chemistry.

Human sexual behavior may be influenced by smells other than pheromones.

Sperm cells may have a smell that helps them find their way to female eggs.

In addition to stirring sexual feelings and behaviors, smell is important in triggering memories.

A smell can connect us to a memory.

Americans suffer from disorders of taste, smell, and both.

When we're younger, advocates claim that essential replaces it.

These losses can be caused by diseases, such as diabetes and high blood pressure, and oils derived from plants have special healing powers.

There are many disorders of olfaction.

Although not as serious as depression, anxiety disorders, insomnia, and deafness, they can pose several dangers, such as an inability to detect gas other ailments.
The smells of leaks and spoiled food are pleasant.
Damage to the olfactory nerve, along such plants can lift our moods a bit, with brain damage caused by Parkinson's and Alzheimer's diseases there's little evidence that they possess magical can damage our sense of smell and ability to identify odors.

Losing our sense of taste can affect our health.

Patients with cancer who lose their sense of taste are more likely to suffer from malnutrition, are less able to tolerate the side effects of treatments, and have less energy to recover quickly.
Adding flavor enhancers to the diet of the elderly can improve their health status.
It's possible that taste adds an essential "zest" to life, a psychological flavoring that can help to ward off disease by boosting appetite.

The nonhuman animals, the chemicals that French Spiderman, has scaled the world's tallest skyscrapers using only chalk on his hands and climbing shoes.

The most potent effects on sexual senses of touch, body position, and balance are what he must rely on.
One miscalculation, one slip of his foot, and his behaviors are all odorless.

Roberts has three body senses that work together.

There are a variety of stimuli that are activated by the somatosensory system.

This sense is different from vision and auditioning, each of which focuses on a single type of stimuli.

Light touch or deep pressure, hot or cold temperature, or chemical or mechanical injury that produces pain are some of the stimuli that our somatosensory system responds to.

The pattern of a letter written in Braille can be very specific and can be generalized to a large area of the body.

Referred pain can be caused by damage to internal organs, such as an ache in the left arm or shoulder during a heart attack.

The French endings are distributed differently across our body surface.

He relies on his senses of touch, body position, and balance to our fingertips, which explains why it really hurts when we cut our finger in a paper scale skyscraper with only chalk and cut.
We have the most in the middle of our shoes.

The skin has many nerve endings that detect pressure, temperature, and pain.

Ice cream and other cold substances can cause pain in the brain.

Touch and pain have different functions.

When something feels hot to avoid a serious burn, touch tells us, whereas pain tells us to take care of injuries, which can often wait a little while.

Touch and pain information can cause local reflexes to be activated.

When we touch a fire or hot stove, we pull away immediately to avoid getting burned.

The somatosensory cortex is reached after touch and pain information travels upward through parts of the brain stem and thalamus.

The association areas of the parietal cortex are active during touch information.

Pain comes in many different forms: sharp, stabbing, throbbing, burning, and ache.

Many of the types of pain perception relate to the pain causing stimuli--thermal, chemical, or mechanical--that can be acute, short-lived, or even lasting years.
People have different thresholds for pain.
People with red hair require more anesthesia than people with other hair.
This correlational finding doesn't mean that red hair causes lower pain thresholds.

People with the genetic variation associated with red hair are more likely to avoid dental care than people with no similar genetic variation.

We can't measure pain the same way as touch.

Pain has a large emotional component.
Pain information goes to the somatosensory cortex and the limbic centers in the brain.
Pain is associated with anxiety, uncertainty, and helplessness.

Scientists believe we can control pain by controlling our thoughts and emo tions.

Depending on our psychological state, the gate control model can account for how pain varies from situation to situation.

Ice cream and other cold substances don't cause pain in our brains.
"Brain freeze" doesn't affect the brain at all.
It's produced by constriction of blood vessels in the roof of our mouths, followed by an expansion of these blood vessels, causing pain.

The gate control model suggests that the Watch Gate Control Theory of Pain stimulation competes with and blocks the pain from consciousness.

Scientists discovered that they could relieve the pain of patients with burns undergoing physical therapy, wound care, and painful skin grafts by placing them in a virtual environment populated by snowmen and igloos.

When people think about pain in such a way that they will not be able to bear it, it can cause a lot of distress.

Patrick Wall showed that the brain controls activity in the spine, allowing us to ignore pain or turn up.

The placebo effect has a strong effect on subjective reports of pain.
When people are told that a placebo cream will alleviate their pain, brain scans show that activity in the spine is reduced.
The body's production of its natural painkillers may be stimulated by placebos.
The glial cells in the spine amplify pain and scientists are trying to find ways to deactivating them.

The healthcare profession Ruling Out Rival Hypotheses treats certain ethnic groups differently.

Some of the differences in reports of pain could be attributed to important alternative visits.

Some popular psychologists think so.

Firewalkers are popular in India, Japan, North Africa, and the Polynesian islands.
The practice of firewalking has been around for as long as 1200 BC.

Motivational classes promise that ordinary people don't try it at home.

Success in firewalking has nothing to do with pain sensitivity and everything to do with physics.

The type of coal or wood used in firewalking has a low rate of heat exchange, so it burns red hot in the center while remaining less hot on the outside.
As long as we walk quickly over the burning embers, we can firewalk.
Accidents can occur if the fire isn't prepared properly or if the firewalker walks too slowly.
Thirty firewalkers who participated in a Tony Robbins motivational seminar in Dallas, Texas, suffered mild foot burns and five were hospitalized.

Trying to ignore and suppress chronic pain is the best way to deal with it.

A missing limb feels as if it's in a distorted position.

Patients with phantom limb pain position their other limb so that it reflects the position the amputation limb would assume.

Then the patient does the "mirror equivalent" of the exercise the limb needs to relieve a pain.
Many people believe in the power of mind over pain, but some claim to possess supernatural abilities or "gifts" that relieve pain, and half report less pain after treatment.

The results were agreed to by psychologists at the University of Bond and British researchers.

They used the healing powers in a study of 120 chronic pain sufferers.

The researchers found reports before and after face-to-face versus distant spiritual volunteers suffering from pain caused by cancer, chronic back healing compared with no spiritual healing.

Despite the popularity of spiritual healing in England, the method lacks scientific support.
Half of the participants were assigned to a group that received psychic healing and spiritual healing.
Half to a control condition that didn't.
The authors couldn't rule out a placebo effect in the study because they didn't have a placebo treatment or blinding of the thera participants.

In the healing condition, the psychic Lyvers and colleagues addressed the placebo effect healer, who viewed and touched photographs of the participants with a double-blind design, and rated their participants with chronic pain in another room.

The healer was given a five-point scale to assess the degree of chronic pain needed.

They did not find any correlation between psychic healing and decreased pain, and how to test participants' levels of pain before ever.

Researchers compared their beliefs in psychic phenomena.
On average, the scores showed no change before normal.

The scientific consensus has been for a long time that we can ignore pain, or at least tolerate it, if we are willing to put up with it.

This strategy doesn't work well with chronic pain.
It is possible to reduce pain and accompanying distress by practicingMindfulness meditation, in which meditators are instructed to accept pain nonjudgmentally, rather than ignoring or suppressing it.
In one approach, practitioners observe pain sensations, emotions, and attitudes, and mentally shuttle between pleasant and neutral body sensations.

The illusion must be realistic.

Seventeen out of 18 patients were successfully treated for phantom limb pain with the mirror box after amputations of one or more lower limbs because of the 2010 earthquake in Haiti.

A placebo effect seems to reduce pain by psychic healing.

When we can't feel pain, the mirror box has two chambers.

Some people have a mirror in the center while others don't.
The participant looks at her hand disorders that make it hard to sense pain.
Research on pain in the box creates an illusion that it serves an essential function.
Her left birth is an extremely rare condition that can cause pain insensitivity from a mirror image of her right hand.
Children with this condition are completely unable to detect pain, but this box can sometimes help.

Lacking any awareness of pain, they may chew off parts of their bodies, like their fingertips positioning the intact limb as the phantom or the ends of their tongues, without realizing it.

This condition can be very dangerous if the limb appears to be positioned.
Some people are not interested in moving it to a more comfortable position.

You're sitting right now.

Your brain is taking care of all that, so you may not be thinking about body control or keeping your head and shoulders up.
If you decided to stand up and grab a snack, you would need to maintain your posture and balance.

Ashlyn Blocker has congenital insensitivity to pain.

They are telling the inside story.
It is a muscle stretch and force.
We can tell what our disorder is by looking at the information from these two sources.
There are two types of proprioceptors, those that detect pain and those that can't regulate body temperature.
Because of an inability to sweat,ceptive information enters the spine and travels upward.
The brain stem and thalamus of her parents need to reach the somatosensory and motor cortexes.
She's prone to eating hot a sense of our intentions to get a perception of our body's location, which is why our brains combine information from our muscles and tendons.

She may hurt herself on the playground.

In addition to the cochlea, the inner and continue to play.

The canals help us maintain our balance.

Our awareness of the vestibular sense is limited because it isn't represented in our cerebral cortex.