Pratik Raul, University of Canberra; Jeroen van Boxtel, University of Canberra, and Jovana Acevska, University of Canberra

Autism is a neurodevelopmental difference associated with specific experiences and characteristics.

For decades, autism research has focused on behavioural, cognitive, social and communication difficulties. These studies highlighted how autistic people face issues with everyday tasks that allistic (meaning non-autistic) people do not. Some difficulties may include recognising emotions or social cues.

But some research, including our own study, has explored specific advantages in autism. Studies have shown that in some cognitive tasks, autistic people perform better than allistic people. Autistic people may have greater success in identifying a simple shape embedded within a more complex design, arranging blocks of different shapes and colours, or spotting an object within a cluttered visual environment (similar to Where’s Wally?). Such enhanced performance has been recorded in babies as young as nine months who show emerging signs of autism.

How and why do autistic individuals do so well on these tasks? The answer may be surprising: more “neural noise”.

What is neural noise?

Generally, when you think of noise, you probably think of auditory noise, the ups and downs in the amplitude of sound frequencies we hear.

A similar thing happens in the brain with random fluctuations in neural activity. This is called neural noise.

This noise is always present, and comes on top of any brain activity caused by things we see, hear, smell and touch. This means that in the brain, an identical stimulus that is presented multiple times won’t cause exactly the same activity. Sometimes the brain is more active, sometimes less. In fact, even the response to a single stimulus or event will fluctuate continuously.

Neural noise in autism

There are many sources of neural noise in the brain. These include how the neurons become excited and calm again, changes in attention and arousal levels, and biochemical processes at the cellular level, among others. An allistic brain has mechanisms to manage and use this noise. For instance, cells in the hippocampus (the brain’s memory system) can make use of neural noise to enhance memory encoding and recall.

Evidence for high neural noise in autism can be seen in electroencephalography (EEG) recordings, where increased levels of neural fluctuations were observed in autistic children. This means their neural activity is less predictable, showing a wider range of activity (higher ups and downs) in response to the same stimulus.

In simple terms, if we imagine the EEG responses like a sound wave, we would expect to see small ups and downs (amplitude) in allistic brains each time they encounter a stimulus. But autistic brains seem to show bigger ups and downs, demonstrating greater amplitude of neural noise.

Many studies have linked this noisy autistic brain with cognitive, social and behavioural difficulties.

But could noise be a bonus?

The diagnosis of autism has a long clinical history. A shift from the medical to a more social model has also seen advocacy for it to be reframed as a difference, rather than a disorder or deficit. This change has also entered autism research. Neuroaffirming research can examine the uniqueness and strengths of neurodivergence.

Psychology and perception researcher David Simmons and colleagues at the University of Glasgow were the first to suggest that while high neural noise is generally a disadvantage in autism, it can sometimes provide benefits due to a phenomenon called stochastic resonance. This is where optimal amounts of noise can enhance performance. In line with this theory, high neural noise in the autistic brain might enhance performance for some cognitive tasks.

Our 2023 research explores this idea. We recruited participants from the general population and investigated their performance on letter-detection tasks. At the same time, we measured their level of autistic traits.

We performed two letter-detection experiments (one in a lab and one online) where participants had to identify a letter when displayed among background visual static of various intensities.

By using the static, we added additional visual noise to the neural noise already present in our participants’ brains. We hypothesised the visual noise would push participants with low internal brain noise (or low autistic traits) to perform better (as suggested by previous research on stochastic resonance). The more interesting prediction was that noise would not help individuals who already had a lot of brain noise (that is, those with high autistic traits), because their own neural noise already ensured optimal performance.

Indeed, one of our experiments showed people with high neural noise (high autistic traits) did not benefit from additional noise. Moreover, they showed superior performance (greater accuracy) relative to people with low neural noise when the added visual static was low. This suggests their own neural noise already caused a natural stochastic resonance effect, resulting in better performance.

It is important to note we did not include clinically diagnosed autistic participants, but overall, we showed the theory of enhanced performance due to stochastic resonance in autism has merits.

Why this is important?

Autistic people face ignorance, prejudice and discrimination that can harm wellbeing. Poor mental and physical health, reduced social connections and increased “camouflaging” of autistic traits are some of the negative impacts that autistic people face.

So, research underlining and investigating the strengths inherent in autism can help reduce stigma, allow autistic people to be themselves and acknowledge autistic people do not require “fixing”.

The autistic brain is different. It comes with limitations, but it also has its strengths.

Pratik Raul, PhD candidiate, University of Canberra; Jeroen van Boxtel, Associate professor, University of Canberra, and Jovana Acevska, Honours Graduate Student, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We know vaccines have been a miracle for public health. Now, new research led by the World Health Organization has found vaccines have saved an estimated 154 million lives in the past 50 years from 14 different diseases. Most of these have been children under five, and around two-thirds children under one year old.

In 1974 the World Health Assembly launched the Expanded Programme on Immunization with the goal to vaccinate all children against diphtheria, tetanus, pertussis (whooping cough), measles, polio, tuberculosis and smallpox by 1990. The program was subsequently expanded to include several other diseases.

The modelling, marking 50 years since this program was established, shows a child aged under ten has about a 40% greater chance of living until their next birthday, compared to if we didn’t have vaccines. And these positive effects can be seen well into adult life. A 50-year-old has a 16% greater chance of celebrating their next birthday thanks to vaccines.

What the study did

The researchers developed mathematical and statistical models which took in vaccine coverage data and population numbers from 194 countries for the years 1974–2024. Not all diseases were included (for example smallpox, which was eradicated in 1980, was left out).

The analysis includes vaccines for 14 diseases, with 11 of these included in the Expanded Programme on Immunization. For some countries, additional vaccines such as Japanese encephalitis, meningitis A and yellow fever were included, as these diseases contribute to major disease burden in certain settings.

The models were used to simulate how diseases would have spread from 1974 to now, as vaccines were introduced, for each country and age group, incorporating data on increasing vaccine coverage over time.

Children are the greatest beneficiaries of vaccines

Since 1974, the rates of deaths in children before their first birthday has more than halved. The researchers calculated almost 40% of this reduction is due to vaccines.

The effects have been greatest for children born in the 1980s because of the intensive efforts made globally to reduce the burden of diseases like measles, polio and whooping cough.

Some 60% of the 154 million lives saved would have been lives lost to measles. This is likely due to its ability to spread rapidly. One person with measles can spread the infection to 12–18 people.

The study also found some variation across different parts of the world. For example, vaccination programs have had a much greater impact on the probability of children living longer across low- and middle-income countries and settings with weaker health systems such as the eastern Mediterranean and African regions. These results highlight the important role vaccines play in promoting health equity.

Vaccine success is not assured

Low or declining vaccine coverage can lead to epidemics which can devastate communities and overwhelm health systems.

Notably, the COVID pandemic saw an overall decline in measles vaccine coverage, with 86% of children having received their first dose in 2019 to 83% in 2022. This is concerning because very high levels of vaccination coverage (more than 95%) are required to achieve herd immunity against measles.

In Australia, the coverage for childhood vaccines, including measles, mumps and rubella, has declined compared to before the pandemic.

This study is a reminder of why we need to continue to vaccinate – not just against measles, but against all diseases we have safe and effective vaccines for.

The results of this research don’t tell us the full story about the impact of vaccines. For example, the authors didn’t include data for some vaccines such as COVID and HPV (human papillomavirus). Also, like with all modelling studies, there are some uncertainties, as data was not available for all time periods and countries.

Nonetheless, the results show the success of global vaccination programs over time. If we want to continue to see lives saved, we need to keep investing in vaccination locally, regionally and globally.

Meru Sheel, Associate Professor and Epidemiologist, Infectious Diseases, Immunisation and Emergencies Group, Sydney School of Public Health, University of Sydney and Alexandra Hogan, Mathematical epidemiologist, UNSW Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.