In the first pilot study asking adults on the autism spectrum about their experiences with driving, researchers at Drexel University found significant differences in self-reported driving behaviors and perceptions of driving ability in comparison to non-autistic adults. As the population of adults with autism continues growing rapidly, the survey provides a first step toward identifying whether this population has unmet needs for educational supports to empower safe driving – a key element of independent functioning in many people’s lives.

“Previous research in my lab has included extensive research in driving capacity with people who have a variety of conditions such as multiple sclerosis or who had experienced traumatic brain injury,” said study co-author Maria Schultheis, PhD, an associate professor of psychology at Drexel. “When we investigate whether and under what circumstances a condition or neurological difference might affect driving ability, as a standard starting point we want to go to individuals and find out from their perspective what problems they are having on the road, in their real-world experience. That question is pivotal to shape and inform the goals of long-term research – and is especially important when we turn to look at a developmental difference like autism, where there has been too little research to establish yet whether widespread driving difficulties exist.”

Only a few previous studies have examined driving ability in individuals with autism, and those studies focused on adolescents and new drivers rather than experienced adult drivers. These studies relied on parent surveys and evaluations of discrete aspects of driving performance. The new Drexel study, published early online this month in the Journal of Autism and Developmental Disorders, used a validated survey that has been extensively used in driving research, and asked adult licensed drivers on the autism spectrum to describe their first-hand, real-world driving experiences.

“We were beginning to see discussion in the research literature that aspects of autism spectrum disorders, such as neurocognitive challenges and social recognition difficulties, could make it likely that members of this population would experience significant challenges with driving,” said the study’s lead author Brian Daly, PhD, an assistant professor of psychology in Drexel’s College of Arts and Sciences. “But that assumption hadn’t been studied in adult drivers, or based on the experiences of the drivers themselves – so these were the questions we explored.”

In this survey, adults with autism spectrum disorders reported earning their drivers’ licenses at a later age, driving less frequently and putting more restrictions on their own driving behaviors (such as avoiding driving on highways or at night), on average compared to non-autistic adults. The respondents with autism spectrum disorders also reported more traffic violations.

Because this pilot study was relatively small and based on self-reports of 78 ASD respondents and 94 non-ASD comparison participants, Schultheis and Daly noted that the differences they found were open to several possible interpretations. Autistic adults may have reported driving less often and restricting their behaviors out of self-awareness of actual difficulties or deficiencies in their driving. These difficulties and/or reduced driving exposure could also explain the higher rate of reported violations.

Alternatively, it is possible that the respondents on the autism spectrum were more honest in their answers, but no worse at driving than everyone else.

“In driving research, it’s well established that people have a positive bias when reporting their own driving skills,” said Schultheis. “Because the study relied on self-reported answers, we can’t rule out whether the respondents with autism were simply being more descriptive and honest about their difficulties than the control group.”

One intriguing finding that Daly and Schultheis noted was that the difficulties adults with autism reported were not clustered in any specific areas, such as problems related to social processing of other drivers’ or pedestrians’ expected behaviors, or difficulties with neurocognitive aspects of driving such as motion perception and reaction time.

“It suggests that the challenges these individuals are facing are more global than specific,” Daly said.

“This is such an important study,” said Paul Shattuck, PhD, an associate professor and director of the research program area in life course outcomes at the A.J. Drexel Autism Institute, who was not involved in conducting the study. “Cognitively-able adults on the autism spectrum face many barriers to full participation in society. Facilitating access to transportation options will increase the capacity for these adults to contribute to their communities.”

Three-dimensional reconstruction of electron microscopic images showing a synaptic spine (blue) of a new neuron (pink), which forms a synapse with another neuron (light blue), engulfed by microglia (green) in the adult mouse olfactory bulb CREDIT © 2022 Kurematsu et al. Originally published in Journal of Experimental Medicine.

A research group led by Kazunobu Sawamoto, a professor at Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences and National Institute for Physiological Sciences, and Chihiro Kurematsu, a fourth-year student at Nagoya City University School of Medicine, has elucidated the mechanism that controls synaptic pruning of new neurons in the adult brain.

In the mammalian brain, neural stem cells exist even after birth, and new neurons are produced. As these new neurons mature, they form connections called synapses with existing neurons to create functional neural circuits. For the brain to develop and function normally, it is important to maintain an appropriate number of synapses, but the mechanism to regulate the number of synapses has not been fully understood. Cells called microglia, which exist near nerve cells, play an important role in this process. Microglia can “eat” (phagocytose) dead cells and are also known to digest extra synapses during development. However, it was unknown how new neurons in the adult brain eliminate extra synapses during maturation.

Sawamoto’s group focused on phosphatidylserine (PS), a molecule that usually resides inside the cell membrane, but is found on the external surface of dead cells or developing synapses, where it is recognized by microglia. First, the researchers used an electron microscope to examine the microglia in detail and observed that microglia actually engulf synapses. Next, they examined the localization of PS and found that PS is exposed outside the cell membrane at synapses in the adult mouse brain, especially at less active synapses.

“To study whether microglial PS detection is important for synaptic pruning and normal neuron maturation in the adult brain, we needed to see what happens when PS is masked in living adult mice,” Sawamoto said.

Finally, they generated genetically modified mice in which PS outside the cell membrane was masked by a protein, and observed microglia and synapses. As a result, they found that in these mice, microglia could not eat synapses properly, resulting in extra synapses left behind.  Furthermore, neurons in these mice showed electrophysiological abnormalities. These results indicate that the synaptic pruning of newborn neurons by microglia is PS-dependent in the adult brain, and that this mechanism is important for the correct maturation of newborn neurons.

Recent studies have shown that new neurons are also produced in the human brain during the neonatal period, and microglial synaptic pruning is believed to be important for postnatal brain development.

“We hope that investigating PS-dependent synaptic elimination in mouse models of brain diseases will lead to the development of new therapeutic strategies for human pathological conditions such as autism, where abnormalities in microglia and synaptic density have been observed,” said Kurematsu.

This is Dr. Gnanathusharan Rajendran of University of Strathclyde. CREDIT University of Strathclyde

Young autistic people may find it difficult to multitask because they stick rigidly to tasks in the order they are given to them, according to research led by an academic at the University of Strathclyde.

The study also found that difficulty with ‘prospective memory’- remembering to carry out their intentions- may contribute to the challenges they face.

The researchers presented the pupils with a series of tasks, such as collecting and delivering a book and making a cup of hot chocolate, to be carried out within a time limit of eight minutes. These activities were carried out in a computer-generated virtual environment.

They found that the pupils did not appear to deviate from the order in which the tasks were listed, although doing so could have saved them time. They also broke several rules for the tasks, notably only being allowed to go up one staircase and down another.

An equal number of pupils with and without autism) took part in the study. The researchers will be exploring further the causes of the pupils’ problems with multitasking, in areas such as planning, memory, time pressure and inhibitory control.

Dr Gnanathusharan Rajendran, a lecturer in Psychology at Strathclyde, led the research, which also involved the University of Edinburgh and Liverpool John Moores University. He said: “Our research offers a real insight into the problems young people with autism have with multitasking and points the way to further investigation for possible solutions. By using, for the first time, a virtual environment, we have been able to examine what may lie behind these problems more closely than might be possible in a real-world setting.

“The pupils with autism achieved tasks when they were given to them singly but difficulties emerged when they were asked to interleave the tasks with each other. There was no difference in the time taken by the groups but the pupils with autism completed fewer tasks.

“The exercise could help to deal with these multitasking problems. The tasks or their environment could be changed to see if there is any influence on the outcomes and they could also be a tool for teaching and training.”###

New research in mice has identified neurons in the brain that influence competitive interactions between individuals and that play a critical role in shaping the social behaviour of groups. Published in Nature by a team led by investigators at Massachusetts General Hospital (MGH), the findings will be useful not only for scientists interested in human interactions but also for those who study neurocognitive conditions such as autism athat are characterized by altered social behaviour.

“Social interactions in humans and animals occur most commonly in large groups, and these group interactions play a prominent role in sociology, ecology, psychology, economics and political science,” says lead author S. William Li, an MD/PhD student at MGH. “What processes in the brain drive the complex dynamic behaviour of social groups remains poorly understood, in part because most neuroscience research thus far has focused on the behaviours of pairs of individuals interacting alone. Here, we were able to study the behaviour of groups by developing a paradigm in which large cohorts of mice were wirelessly tracked across thousands of unique competitive group interactions.”

Li and his colleagues found that the animals’ social ranking in the group was closely linked to the results of the competition, and by examining recordings from neurons in the brains of mice in real-time, the team discovered that neurons in the anterior cingulate region of the brain store this social ranking information to inform upcoming decisions.

“Collectively, these neurons held remarkably detailed representations of the group’s behaviour and their dynamics as the animals competed together for food, in addition to information about the resources available and the outcome of their past interactions,” explains senior author Ziv M. Williams, MD, a neurosurgical oncologist at MGH. “Together, these neurons could even predict the animal’s own future success well before competition onset, meaning that they likely drove the animals’ competitive behaviour based on whom they interacted with.”

Manipulating the activity of these neurons, on the other hand, could artificially increase or decrease an animal’s competitive effort and therefore control its ability to successfully compete against others. “In other words, we could tune up and down the animal’s competitive drive and do so selectively without affecting other aspects of their behaviour such as simple speed or motivation,” says Williams.

The findings indicate that competitive success is not simply a product of an animal’s physical fitness or strength, but rather, is strongly influenced by signals in the brain that affect the competitive drive. “These unique neurons are able to integrate information about the individual’s environment, social group settings, and reward resources to calculate how to best behave under specific conditions,” says Li.

In addition to providing insights into group behaviour and competition in different sociologic or economic situations and other settings, identifying the neurons that control these characteristics may help scientists design experiments to better understand scenarios in which the brain is wired differently. “Many conditions manifest in aberrant social behaviour that spans many dimensions, including one’s ability to understand social norms and to display actions that may fit the dynamical structure of social groups,” says Williams. “Developing an understanding of group behaviour and competition holds relevance to these neurocognitive disorders, but until now, how this happens in the brain has largely remained unexplored.”