A pioneering therapy aimed at lowering anxiety by tuning into your own heartbeat is being put to the test in the first clinical trial of its kind.

The treatment, known as interoception-directed therapy, is being tested on 120 autistic people, for whom anxiety is a common problem.

The trial follows a decade’s research by Prof Sarah Garfinkel, a psychologist at the University of Sussex, into the intriguing ways that interactions between the heart and the brain influence emotions and behaviour. The latest work, funded by the mental health charity MQ: Transforming Mental Health, aims to turn these insights into a therapy.

“Anxiety is really high in the autistic population,” said Garfinkel. “Fifty percent of people with autism also potentially have anxiety, which is so high and really not known.”

The ability to tune into the activity of our internal organs is called interoception and there is emerging evidence that this ability is linked to how well a person is able to identify their own emotional state and to empathise with others.

Garfinkel believes that altered interoception may be a factor in why autistic people experience the world differently. Her work has shown that autistic people tend to find it far harder to detect their own heartbeats – and the worse they are at this task, the greater their anxiety tends to be.

Prof Sarah Garfinkel, whose research has helped lead to the trial of interoception-directed therapy. Photograph: Martin Godwin/The Guardian

The 120 trial participants are being asked to complete eight training sessions over several weeks. During training, their heartbeat is tracked using a pulse oximeter and they are asked to “listen in” to their heart and count how many beats occur in a set time period. They are then given the correct answer and the exercise is repeated.

A pilot study involving participants without autism showed the training improved people’s interoceptive awareness and significantly reduced anxiety levels.

Becka, a 41-year-old from Brighton, who was diagnosed as autistic as an adult, is one of the trial participants. “I don’t really remember a time I wasn’t anxious,” she said. “It seems [to be] always there in the background … and at times I have felt taken over by my anxiety.”

Becka struggles to manage sensory overload, saying the world sometimes feels “intense, loud, fast, painful”, which she said contributes to feelings of stress and anxiety. Focusing on her heart and breathing is something she has learned to do naturally as a coping strategy and she enjoyed the training. “It was good to tune in and focus on my heartbeat,” she said. “No matter how busy outside or inside is, I can still focus on that.”

Garfinkel’s interest was sparked after reading a scientific paper on autism and empathy.

“I found within this paper an almost buried graph showing that if you measure the bodily response of someone with autism to seeing someone in pain, it’s actually greater,” said Garfinkel. “They have a heightened bodily response to the pain of others.”

This finding runs counter to the idea that autistic people “lack empathy”, she said. “Early accounts of autism sometimes said they didn’t have empathy and for me that’s really not true at all,” she said.

However, autistic people can feel disconnected from their own emotions and struggle to assess what people around them are feeling.

“It made me wonder, if they’re having this very heightened bodily response, is there something altered about their interoception, their capacity to sense and use these signals?”

One hypothesis is that, in autistic people, empathetic responses are occurring at the brain’s fast, instinctive level, reflected by changes in heartbeat. However, the brain may be less adept at interpreting these signals and so having these constant unexplained increases in heart rate could potentially leave people feeling under threat, causing anxiety.

Garfinkel hopes the latest trial could provide further insights into whether the hypothesis, which is under active debate in the field, is correct. The participants will also have brain scans before and after training to look for any potential changes in a brain area called the insula, which picks up signals from the heart and is also involved in emotion.

Sophie Dix, director of research at MQ: Transforming Mental Health, said: “This project has so much potential to inform treatments and further understanding of anxiety in autistic people. Research like this provides hope for better treatments for mental health kindled by our increased understanding of the link between the mind and the body.”

How to test your own interoceptive awareness

1) Find a quiet place.

2) Set a timer for one minute.

3) Close your eyes and try to detect your heartbeat. When you’re ready, start the timer and try to count your heartbeats for a minute.

4) Repeat the exercise, but this time feeling your pulse to take an accurate reading of your heart rate.

Tip: if you’re struggling to tune into your heartbeat, try running up and down some stairs or doing star jumps until your heart pounds and then try to stick with it as it returns to normal.