Dr Justin O'Brien
Senior Lecturer in Psychology

 

• Face and Expression Recognition: Examining how facial expressions are processed across the lifespan and how high-level concepts influence emotion recognition.
• Neuroimaging and Facial Motion: Understanding the neural correlates of facial motion perception, particularly in individuals with Autism Spectrum Disorder (ASD).
• Developmental Studies: Investigating early perceptual abilities in infants and how these abilities relate to social cognition.
• Replication Studies: Re-examining the reliability of previous findings in the context of moral judgment and gustatory experiences.
• Visual Processing in Neurodevelopmental Disorders: Comparing visual processing challenges between individuals with ASD, dyslexia, and Asperger syndrome.
• Fractal Rotation and Motion Perception: Exploring the neural mechanisms involved in processing complex motion patterns.

Face and Expression Recognition

Changes in Functional Connectivity and Facial Expression Processing

Murray, O'Brien & Kumari (2022) investigated how aging influences the brain's functional connectivity during facial expression processing across the adult lifespan. The study, involving participants aged 20 to 65, utilized functional magnetic resonance imaging (fMRI) to measure changes in connectivity between regions like the amygdala, medial prefrontal cortex, and right posterior superior temporal sulcus. The results indicated a decline in connectivity, particularly when processing negative emotions such as anger and fear, suggesting an age-related decline in emotional recognition.

Role of Stimulus-Based Cues and Conceptual Information

Murray, O'Brien, Sagiv & Garrido (2021) explored the interplay between physical facial cues and conceptual emotion information in emotion perception. Through two studies, the research highlighted that while shape cues influence perceptual tasks, conceptual information plays a dominant role in both behavioral categorization and neural representation of facial expressions. The findings underscore the importance of high-level emotion concepts in understanding facial expressions beyond physical cues.

Neuroimaging and Dynamic Facial Expressions

Neural Correlates of Facial Motion Perception

Girges, O'Brien, & Spencer (2015b) examined how the brain processes natural facial movements using fMRI. The study found significant activation in regions such as the posterior superior temporal sulcus (pSTS), fusiform gyrus, and cerebellum when participants viewed upright facial motion. These results emphasize the importance of using ecologically valid stimuli in studying facial motion perception.

Categorizing Identity from Facial Motion

Girges, Spencer, & O'Brien (2015a) investigated how individuals recognize identities based solely on facial motion cues. The study demonstrated that participants could accurately categorize identities without relying on static facial features, highlighting the significant role of dynamic facial cues in identity recognition.

Developmental Studies

Sensory Processing as a Diagnostic Indicator of Autism

O'Brien et al (2009) investigated the ability to differentiate children with autism from those with learning difficulties and typically developing children by analyzing their responses to sensory stimuli using an adapted version of the Short Sensory Profile (SSP). The research found that children with autism exhibited significantly higher levels of sensory impairments, particularly in auditory hyper-sensitivity and visual stimulus-seeking behaviors, compared to the other groups. These results highlight the importance of sensory processing in the diagnosis of autism, suggesting that sensory profiles can serve as valuable tools in distinguishing autism from other developmental conditions.

This research underscores the evolving understanding of autism, particularly in relation to sensory processing abnormalities. Such findings are significant as they contribute to the refinement of diagnostic criteria for autism, potentially influencing updates to the Diagnostic and Statistical Manual of Mental Disorders (DSM). The study’s results emphasize the need for incorporating sensory processing abnormalities into the diagnostic criteria for autism, as these factors provide critical insights into the distinct sensory challenges faced by individuals with autism.

Perception of Facial Motion in Infants

Spencer, O'Brien, Johnston & Hill (2006) explored infants' ability to discriminate faces using biological motion cues. The study found that infants aged 4 to 8 months could distinguish between different facial motion sequences and recognize individual actors based on unique motion patterns. This early ability suggests that facial motion plays a crucial role in social cognition from a young age.

Visual Motion Form-Processing Deficits in Autism

Spencer & O'Brien (2000) focused on the visual processing challenges in children with high-functioning autism (HFA). The research found significant deficits in global visual processing, particularly in integrating visual form and motion. This study contributes to understanding the distinct visual processing profiles in autism compared to Asperger syndrome.

Spencer & O'Brien (2006) Explored the visual processing deficits in children with high-functioning autism (HFA) and Asperger syndrome. Through experiments measuring form and motion coherence thresholds, the study found that children with HFA exhibited significant deficits in both form and motion coherence, while children with Asperger syndrome did not show such deficits. These findings suggest that while both conditions share core social impairments, there are distinct differences in low-level visual processing, which could indicate different underlying neurobiologies between autism and Asperger syndrome.

Research like this contributes to our evolving understanding of autism and related disorders, leading to refinements in diagnostic criteria, such as those found in the DSM. Studies highlighting specific cognitive and sensory processing deficits play a crucial role in differentiating between various conditions within the autism spectrum, prompting revisions to diagnostic manuals to more accurately reflect these distinctions.

O'Brien et al (2002) Explored the differences in global spatial and motion processing abilities in children with dyspraxia compared to typically developing peers. The findings revealed that children with dyspraxia have significant deficits in global form processing, evidenced by higher thresholds in form coherence tasks. However, they did not show the same level of impairment in motion coherence tasks, indicating that their difficulties may be specifically related to the ventral stream, which is involved in processing visual form information.

These results highlight the unique perceptual challenges faced by children with dyspraxia, distinguishing them from other developmental disorders such as autism, Williams syndrome, and dyslexia, where deficits are more commonly observed in motion processing rather than form processing. This research enhances our understanding of the distinct neural mechanisms underlying dyspraxia and underscores the importance of tailored diagnostic approaches that consider these specific sensory processing differences.

Replication Studies

Reexamining Gustatory Disgust and Moral Judgment

Ghelfi, ... de Haan, ... O'Brien ..., et al. (2019) conducted a large-scale replication study to verify the findings of a previous experiment on gustatory disgust and moral judgment. The replication revealed weaker effects than originally reported, with limited evidence supporting the hypothesis that tasting something bitter intensifies moral judgments. The findings highlight the need for further research into the sensory experiences and moral decision-making relationship.

Visual Processing in Neurodevelopmental Disorders

Volumetric Changes in Dyslexia and Autism

Tsermentseli, O'Brien & Spencer (2012) compared structural brain differences between adults with dyslexia and autism using voxel-based morphometry. The study found higher global gray matter volume in individuals with autism but no significant differences in regional brain volumes. These results suggest that the neuroanatomical abnormalities may require more sensitive techniques to detect.

Form and Motion Coherence in ASD and Dyslexia

Tsermentseli, O'Brien & Spencer (2008) explored visual processing in individuals with Autism Spectrum Disorders (ASD) and dyslexia. The study revealed that those with high-functioning autism exhibited significant impairments in both form and motion coherence tasks, whereas individuals with Asperger syndrome and dyslexia did not. This research highlights the distinct visual processing challenges associated with each condition.

Fractal Rotation and Motion Perception

Isolating Mechanisms for Form-Dependent Motion

Benton, O'Brien & Curran (2007) investigated the neural processes underlying motion perception using a fractal rotation stimulus. The study found that after exposure to this complex motion, participants experienced reduced after-effects, suggesting distinct neural mechanisms at play. This research offers insights into how the brain interprets complex visual forms.