Category: Neuroscience

Hate the sound of people chewing, breathing or speaking? You may have misophonia.

Misophonia, which literally means hatred of sound, is linked to a super-sensitised brain connection, a new study finds.

What is misophonia?

People with misophonia find certain trigger noises to be so irritating they can promote avoidance, annoyance, anger or even losing control and lashing out.

Typical examples include the sound of breathing, chewing or even speaking.

The sounds most likely to irritate people with misophonia are repetitive and usually involve the mouth, throat or facial area.

People with misophonia may avoid social situations or use headphones to avoid the triggering sounds.

Misophonia is thought to affect between 6 and 20 percent of people to some degree.

It can cause significant distress and interfere with daily life.

Causes of misophonia

A new study finds that there is a unique connectivity between the brain’s auditory and motor cortices in people with misophonia.

Dr Sukhbinder Kumar, the study’s first author, said:

“Our findings indicate that for people with misophonia there is abnormal communication between the auditory and motor brain regions — you could describe it as a ‘supersensitised connection’.

This is the first time such a connection in the brain has been identified for the condition.”

Other possible causes of misophonia are:

• A dysfunction in the central auditory system.
• Other mental health conditions: people with anxiety disorders, such as OCD and Tourettes, are more likely to have misophonia.
• Genetics: it runs in families.

Treatment

Being a relatively newly recognised condition, misophonia has no established treatments.

However, some approaches may be effective, including:

• Cognitive-behavioural therapy: has been found to help around half of people with misophonia. This focuses on changing negative thoughts related to the condition (Schröder et al., 2017).
• Tinnitus retraining therapy: using relaxation training plus wearing devices that produce attention-diverting noises.
• Relaxation techniques

Coping

People typically cope with misophonia in a variety of ways:

• Wearing headphones
• Using earplugs
• Stress management
• Music or background noise
• Planning ahead for when an outburst is coming (then use relaxation, visualisation, deep breathing).

More about this study

The study included 33 people with misophonia whose brains were scanned.

Compared with a control group, those with misophonia showed a stronger response between the brain’s auditory and motor cortices.

There was also increased activation in visual regions, Dr Kumar explained:

“What surprised us was that we also found a similar pattern of communication between the visual and motor regions, which reflects that misophonia can also occur when triggered by something visual.

This lead us to believe that this communication activates something called the ‘mirror system’, which helps us process movements made by other individuals by activating our own brain in a similar way — as if we were making that movement ourselves.

We think that in people with misophonia involuntary overactivation of the mirror system leads to some kind of sense that sounds made by other people are intruding into their bodies, outside of their control.

Interestingly, some people with misophonia can lessen their symptoms by mimicking the action generating the trigger sound, which might indicate restoring a sense of control.

Using this knowledge may help us develop new therapies for people with the condition.”

The study was published in The Journal of Neuroscience (Kumar et al., 2021).

What happens in the brain when we touch ourselves, compared with when someone else touches us.

We cannot tickle ourselves because the brain automatically reduces sensory inputs from the skin when we touch ourselves, research finds.

The dampening of inputs from self-touch starts as early as the spinal cord — in other words, before the ‘touch’ message even reaches the brain.

This helps explain why we cannot tickle ourselves.

It may also help explain why people grab themselves when injured.

Holding an injured arm, for example, may reduce the sense of pain because of this automatic process.

The conclusions come from a study in which people’s brains were scanned while their arms were stroked by both another person and themselves (but not at the same time!).

Dr Rebecca Böhme, the study’s first author, explained the results:

“We saw a very clear difference between being touched by someone else and self-touch.

In the latter case, activity in several parts of the brain was reduced.

We can see evidence that this difference arises as early as in the spinal cord, before the perceptions are processed in the brain.”

The theory goes that our brains are wired to predict how everything we do will affect our senses.

This means most people cannot tickle themselves.

Interestingly, though, some patients with schizophrenia can tickle themselves, suggesting their brains are wired differently.

Dr Böhme said:

“Our results suggest that there is a difference as early as in the spinal cord in the processing of sensory perceptions from self-touch and those from touch by another person.

This is extremely interesting.

In the case of the visual system, research has shown that processing of visual impressions occurs as early as in the retina, and it would be interesting to look in more detail into how the brain modulates the processing of tactile perceptions at the level of the spinal cord.”

The study was published in the journal Proceedings of the National Academy of Sciences (Boehme et al., 2019).

If you watch a baby’s eyes, they move quickly, processing and integrating information.

Time seems to pass faster with age because our eyes and brain get slower, a new theory suggests.

This makes older people feel time is passing quicker now than it was in their youth.

If you watch a baby’s eyes, they move quickly, processing and integrating information.

In contrast, adult’s eyes move more slowly and their brains are more complex.

Signals have further to travel through the brain and take longer, because the whole system is slowing down.

This gives older people the subjective experience that things are happening more quickly.

Imagine the difference between watching a movie in slow motion compared with fast forward.

An older person — who is effectively watching in fast forward —  sees fewer images in the same amount of time, leading to the perception that the film is passing more quickly.

A young person, who is watching in slow motion, has the perception that it is dragging on and on.

Professor Adrian Bejan, the study’s author, said:

“People are often amazed at how much they remember from days that seemed to last forever in their youth.

It’s not that their experiences were much deeper or more meaningful, it’s just that they were being processed in rapid fire.”

In youth, the mind receives many more images each day, Professor Bejan said:

“The human mind senses time changing when the perceived images change.

The present is different from the past because the mental viewing has changed, not because somebody’s clock rings.

Days seemed to last longer in your youth because the young mind receives more images during one day than the same mind in old age.”

The study was published in the journal European Review (Bejan, 2019).

After treatment, the two patients were able to understand language and communicate for the first time in years.

Neuroscientists have used ultrasound to jump-start two people’s brains from a minimally conscious state, a new study reports.

After treatment, the two patients were able to understand language and communicate for the first time inyears.

Ultrasound uses low-intensity focused sound-waves to excite neurons in the thalamus.

The thalamus is a kind of relay station or hub for the brain, routing information to the cerebral cortex and elsewhere.

When in a coma, activity in the thalamus is typically reduced.

In one case, a 56-year-old man was in a minimally conscious state after a stroke.

When in a minimally conscious state, people sleep and wake normally and only show the subtlest signs of consciousness.

Before treatment, the man was lying in bed unable to communicate for 14 months.

After treatment, which involved two sessions of ultrasound across one week, he started showing signs of being able to communicate.

He could grasp and drop a ball and nod and shake his head in response to simple questions.

The case builds on a 2016 report of a 15-year-old who recovered from a coma after ultrasound treatment.

Comas are deeper states than being minimally conscious.

Professor Martin Monti, study co-author, said:

“I consider this new result much more significant because these chronic patients were much less likely to recover spontaneously than the acute patient we treated in 2016 — and any recovery typically occurs slowly over several months and more typically years, not over days and weeks, as we show.

It’s very unlikely that our findings are simply due to spontaneous recovery.”

The other patient was a 50-year-old woman who had been in a minimally conscious state for 2.5 years after a heart attack.

Following treatment, though, she was able to communicate and recognise her family for the first time in years.

Professor Monti said:

“What is remarkable is that both exhibited meaningful responses within just a few days of the intervention.

This is what we hoped for, but it is stunning to see it with your own eyes.

Seeing two of our three patients who had been in a chronic condition improve very significantly within days of the treatment is an extremely promising result.”

Although the improvements of the patients are small, they are still significant.

The 56-year-old was able to recognise photos he was shown, which gave hope to his wife.

Professor Monti said:

“She said to us, ‘This is the first conversation I had with him since the accident.

For these patients, the smallest step can be very meaningful — for them and their families.

To them it means the world.”

Professor Monti hopes a smaller, reasonably-priced ultrasound device can be developed so it can be used in people’s homes.

The study was published in the journal Brain Stimulation (Cain et al., 2021).