Surreal illustration of a face subtly expressing fear, overlaid with neural network patterns, symbolizing heightened sensitivity to emotions in autism.

Decoding Fear: How Autism Affects Sensitivity to Facial Expressions

Samir D’Costa monogram
Samir D’Costa in Mind & Education October 2026 • 4 min read.

"New research reveals heightened sensitivity to subtle fear cues in autistic individuals, challenging common misconceptions and offering insights into social interaction."


For years, a common perception has painted individuals with Autism Spectrum Disorder (ASD) as being less engaged with others, even indifferent. This view suggested a lack of interest in social cues, including facial expressions. However, emerging research is beginning to challenge this traditional understanding, revealing a more nuanced picture of social-emotional processing in autism.

One critical aspect of understanding social interaction is the ability to read and interpret facial expressions accurately. Prior studies, however, haven't always accounted for the differences in how people with ASD attend to faces, particularly their tendency to avoid eye contact. This makes it difficult to determine whether observed differences in brain activity truly reflect an inability to perceive emotions or simply different patterns of attention.

A recent study delved deeper into this question by carefully controlling where participants focused their gaze while viewing emotional faces. The results shed light on a surprising reality: individuals with ASD may actually be more sensitive to subtle expressions of fear, offering a new perspective on the social challenges they experience.

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fMRI Study of Facial Emotion Processing

A study collected fMRI data from 48 participants, including 27 participants with autism spectrum disorder. Participants viewed neutral faces and faces expressing anger, happiness, and fear at low and high intensity. A fixation cross was positioned between the eyes during the task. The design directly examined neural responses to facial expressions across different emotional intensities.

Treatment and Sensory-Processing Limits

A systematic review describes five major categories of mainstream autism spectrum disorder treatment approaches and considers their theoretical bases, therapeutic effects, advantages, limitations, and future directions. A Comparative Effectiveness Review update examined interventions targeting sensory challenges in children with autism spectrum disorder using procedures based on Agency for Healthcare Research and Quality methods. However, a source on exposure therapy reports that sensory-processing issues, particularly hypersensitivity, can make exposure distressing or painful rather than reducing sensitivity. These limitations suggest that standardized approaches may not suit every autistic person's sensory profile.

Unmasking the Sensitivity: Key Findings

Surreal illustration of a face subtly expressing fear, overlaid with neural network patterns, symbolizing heightened sensitivity to emotions in autism.

The research, published in Human Brain Mapping, used fMRI to measure brain activity in adults with and without ASD while they viewed faces expressing anger, happiness, and fear at varying intensities. Crucially, participants were instructed to focus on a fixation cross positioned between the eyes of the faces, ensuring that everyone paid attention to the same area.

Here's what the researchers discovered:

  • Heightened Fear Response: Individuals with ASD showed increased activation in brain regions associated with social processing (the amygdala and ventromedial prefrontal cortex or vmPFC) when viewing faces expressing low-intensity fear compared to the control group.
  • Regulation Challenges: The study also found decreased functional coupling between the amygdala and the vmPFC in the ASD group. This suggests a potential difficulty in regulating the emotional response triggered by these subtle fear cues.
  • Intensity Matters: The differences were most pronounced for low-intensity fear. This nuance hadn't been fully explored in previous studies.
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Amygdala and Network Findings

Research reviewed in Cortex reports growing evidence of over-sensitivity in the subcortical system during face perception in autism. One study found stronger amygdala activation in autistic individuals than in non-autistic controls when they viewed subtle facial expressions of fear. A 2024 bibliometric analysis reported that autism spectrum disorder biomarker research had produced 4,348 documents by December 31, 2022. Separately, a meta-analysis reported decreased activation in the inferior frontal gyrus, middle temporal gyrus, fusiform gyrus, cerebellum, and insula during facial emotion processing at an uncorrected threshold of P < 0.005.

Criticism and Rejection Sensitivity

Several sources describe intense reactions to criticism, disappointment, exclusion, or perceived rejection among some autistic people, sometimes using the term rejection sensitive dysphoria. One source reports that co-occurring anxiety disorders can intensify sensitivity to criticism across social, academic, and workplace settings. A personal account describes how learning disabilities, ADHD, and autism contributed to heightened sensitivity to negative feedback. These sources frame disproportionate distress as a possible response pattern, not as a universal feature of autism.

HSP and Autism Are Not Identical

The comparison sources agree that high sensitivity and autism can overlap but are distinct constructs. Hypersensitivity generally refers to an intense response to sensory stimuli, whereas autism can affect social skills, communication, and behavior. High sensory and emotional sensitivity associated with highly sensitive person or sensory-processing sensitivity concepts may resemble some autistic traits without being equivalent to autism. Recognizing both overlap and difference can support more appropriate understanding and support.

These results suggest that people with ASD aren't necessarily indifferent to emotions. Instead, they may be oversensitive to subtle cues of fear, which can feel overwhelming. The decreased connectivity between brain regions involved in emotional regulation could make it harder to manage these intense feelings, potentially leading to social withdrawal or avoidance of eye contact as a coping mechanism.

Reframing Autism: A New Lens for Understanding

This research offers a valuable shift in perspective, moving away from the outdated notion of autistic individuals as being socially detached. Instead, it highlights the possibility of a heightened sensitivity to social-emotional information, particularly subtle cues of fear.

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Daily-Life Effects of Hypersensitivity

The sources describe hypersensitivity as a common trait associated with autism spectrum disorder that can affect how sensory stimuli are experienced and how people respond to them. Parents and caregivers may face ongoing challenges in understanding and managing these sensitivities in daily life. Unaddressed sensory challenges can contribute to behavior being misinterpreted, creating missed opportunities for connection and support. Another source emphasizes that autistic brains may process sensory input differently from those of neurotypical peers.

Understanding this oversensitivity and the challenges in emotional regulation can help us create more supportive and understanding environments for people with ASD. It reinforces the importance of considering sensory sensitivities and individual coping mechanisms.

Further research is needed to explore these findings using dynamic emotional stimuli and to investigate the potential link between anxiety and social brain abnormalities in ASD. However, these initial results offer a promising avenue for developing more effective interventions and promoting greater social inclusion.

How later studies place the eye-fixation finding

A separate paper likewise cited stronger amygdala activation for subtle fearful expressions, while a study of social scenes discussed the possibility that such cues may be perceived as threatening. These are later authors’ interpretations of related findings, not proof of what participants consciously felt.[1] [2]

Later work has also framed looking away from social cues as a possible way to manage high arousal, rather than evidence of indifference. This is a proposed explanation, not a direct measurement of why any participant avoided eye contact in the 2017 study.[3]

What the facial-expression fMRI study compared

Sample size48 participants, including 27 with ASD[4]
ComparisonExpressive faces at high and low intensity versus neutral faces[4]
Times cited46[4]

Questions a follow-up could resolve

  • Would neural responses still differ if participants could direct their gaze naturally, and would eye-tracking show how looking patterns relate to those responses?[4] [5]
  • Do participants’ reported experiences of eye contact correspond to the brain-response patterns observed during constrained fixation?[5]
  • Would the same pattern be found among autistic people with a wider range of intellectual abilities?[5]

Sources

  1. Overwhelmed by the man in the moon? Pareidolic objects provoke increased amygdala activation in autism. (2023)
  2. Social scene perception in autism spectrum disorder: An eye-tracking and pupillometric study (2019)
  3. Pupillary Contagion in Autism (2018)
  4. Hypersensitivity to low intensity fearful faces in autism when fixation is constrained to the eyes (Wiley, 2017)
  5. Look me in the eyes: constraining gaze in the eye-region provokes abnormally high subcortical activation in autism (pmc.ncbi.nlm.nih.gov)

About this Article -

Written with AI assistance from published research, and reviewed by the Mystum team. See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1002/hbm.23800, Alternate LINK

Title: Hypersensitivity To Low Intensity Fearful Faces In Autism When Fixation Is Constrained To The Eyes

Subject: Neurology (clinical)

Journal: Human Brain Mapping

Publisher: Wiley

Authors: Amandine Lassalle, Jakob Åsberg Johnels, Nicole R. Zürcher, Loyse Hippolyte, Eva Billstedt, Noreen Ward, Eric Lemonnier, Christopher Gillberg, Nouchine Hadjikhani

Published: 2017-09-07

Everything You Need To Know

1

What does the study reveal about how individuals with Autism Spectrum Disorder (ASD) perceive fear?

The study indicates that individuals with Autism Spectrum Disorder (ASD) may have a heightened sensitivity to subtle displays of fear. This heightened sensitivity manifests as increased activity in the amygdala and ventromedial prefrontal cortex (vmPFC), brain regions associated with social processing, specifically when viewing faces expressing low-intensity fear. This challenges the prior understanding that people with ASD are indifferent to social cues.

2

Why is this new understanding of Autism Spectrum Disorder (ASD) important?

The research is significant because it challenges the traditional understanding of Autism Spectrum Disorder (ASD). It moves away from the perception of individuals with ASD as being socially detached and reveals they may be hypersensitive to social-emotional information, particularly subtle cues of fear. This reframing is crucial for developing more effective support strategies and fostering better social understanding. The implications include a need for more nuanced approaches to social interaction and emotional regulation in individuals with ASD.

3

What is the role of the amygdala and ventromedial prefrontal cortex (vmPFC) in the context of this research?

The amygdala and ventromedial prefrontal cortex (vmPFC) are critical brain regions involved in social processing and emotional regulation. The amygdala is primarily responsible for processing emotions, especially fear, and the vmPFC helps regulate emotional responses. In this study, individuals with Autism Spectrum Disorder (ASD) showed increased activation in these regions when exposed to faces expressing low-intensity fear. However, decreased functional coupling between these two areas was also observed, suggesting difficulties in emotional regulation, making it harder to manage these intense feelings.

4

How does this research help explain the social challenges faced by individuals with Autism Spectrum Disorder (ASD)?

The findings suggest that the challenges experienced by individuals with Autism Spectrum Disorder (ASD) in social settings may not stem from a lack of emotional perception but rather from an *oversensitivity* to subtle fear cues. This oversensitivity, combined with potential difficulties in regulating their emotional responses, as indicated by the decreased functional coupling between the amygdala and the ventromedial prefrontal cortex (vmPFC), can lead to social withdrawal or avoidance of eye contact. These behaviors can be seen as coping mechanisms to manage the overwhelming feelings triggered by these cues.

5

Why is the focus on low-intensity fear significant in this study?

The study's focus on low-intensity fear is important because previous studies hadn't fully explored this aspect. The results revealed that individuals with Autism Spectrum Disorder (ASD) exhibited heightened responses to these subtle expressions of fear, which might be missed or misinterpreted in everyday social interactions. This finding is essential for understanding that individuals with ASD are not indifferent to social cues but rather are more attuned to them, especially subtle ones, and the difficulties they face could be related to the intensity and regulation of these perceived emotions.

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