Improving Brain Flexibility in Adults with Autism
Post by Soumilee Chaudhuri
The takeaway
Individuals with autism often exhibit rigid patterns of thinking and perception, which may stem from reduced flexibility in how their brain transitions between different activity states. Previous research has shown that the severity of core autistic traits is linked to this kind of neural rigidity. This study used brain stimulation to temporarily increase brain flexibility in adults with autism.
What's the science?
Autism spectrum disorder (ASD) is widely characterized by differences in how the brain integrates and processes information across multiple systems. One emerging theory suggests that a core feature of autism may be reduced flexibility in the brain's global dynamics—that is, the ease with which the brain transitions between different activity states. These state transitions are essential for adapting to new tasks, shifting attention, interpreting sensory input, and understanding social signals. Previous studies have shown that individuals with autism often have more rigid brain dynamics and fewer state transitions and that this rigidity is associated with key traits of autism, such as repetitive behaviors, heightened sensory perception, and difficulties with nonverbal communication. However, it remains unclear whether this rigidity is simply a byproduct of autism or if it contributes to these traits. This study aimed to determine whether increasing the flexibility of global brain dynamics can causally reduce core traits associated with ASD.
How did they do it?
Using a new brain stimulation technique called brain-state-dependent transcranial magnetic stimulation (TMS), the researchers delivered brief pulses of energy to the brain only when it entered a rigid or inflexible state. To identify these states, the team first recorded resting brain activity from 50 autistic and 50 non-autistic adults using functional MRI (fMRI) and electroencephalography (EEG). They employed a method called energy landscape analysis to identify patterns that indicated brain rigidity. Based on this, they created a tailored stimulation protocol targeting the right superior parietal lobule (SPL)—an area involved in attention, flexibility, and sensory integration.. Forty autistic participants received this personalized TMS during multiple sessions. To evaluate changes, participants completed three tasks before and after the intervention: one measuring task-switching (cognitive flexibility), one assessing visual perception (sensory stability), and one evaluating social understanding (reading facial expressions and vocal tones).
What did they find?
Following the brain-state-dependent stimulation sessions, participants receiving personalized TMS (versus a control group) demonstrated an apparent increase in the brain's ability to shift between different patterns of activity. Immediate improvements in cognitive flexibility accompanied this enhancement in neural flexibility and fluidity. Specifically, autistic participants were more capable of switching between tasks without needing external cues. Improvements in other areas—such as reduced sensory sensitivity and enhanced nonverbal communication—emerged more gradually, becoming noticeable only after multiple sessions. Brain imaging data supported these behavioral improvements. The researchers observed a) stronger communication between brain regions responsible for attention and visual processing (the frontoparietal and visual cortex) and b) improved nonverbal social understanding marked by enhanced connections among the frontoparietal network, the default mode network (involved in self-referential thinking), and the salience network (which helps prioritize social and emotional information). In addition to assessing pre- and post- stimulation sessions, the authors also identified progressive changes throughout the 12-week stimulation period, indicating that the effects last longer than a single session. Changes were noted earlier in cognitive and neural flexibility (at the one-week mark) and later in other areas.
What's the impact?
This study provides strong evidence that targeting brain rigidity in real time using brain-state-dependent stimulation can lead to meaningful changes in the core traits of autism. Findings suggest that there may be a direct connection between brain dynamics and behavior, as shown by increased cognitive flexibility post-stimulation, while the slower improvements in sensory and social functioning point to broader changes across brain networks over time. Taken together, these results are promising and could craft personalized intervention strategies for individuals with autism.
