Summary: A new multi-site brain imaging study finds that people recruit different neural strategies when imitating emotional facial expressions. Rather than revealing a single, categorical difference between those with schizophrenia and people without mental illness, the research identifies distinct sub-groups with different brain activity patterns that could benefit from tailored treatment approaches.
Source: CAMH
A new multi-site functional MRI study published in The American Journal of Psychiatry reports that people fall into distinct neural activation profiles when performing a facial imitation task that reflects social interaction skills. While individuals diagnosed with schizophrenia show, on average, greater social difficulties, their brain responses during this social task are not uniformly different from those of people without mental illness. Instead, the sample organizes into replicable sub-groups with differing patterns of brain activity that may respond differently to interventions.
“Although people with schizophrenia tend to have greater social impairment overall, we took a data-driven approach to let the brain and behaviour patterns emerge without imposing diagnostic categories,” says senior author Dr. Aristotle Voineskos of the Campbell Family Mental Health Research Institute at the Centre for Addiction and Mental Health (CAMH) in Toronto. “The relationship between brain function and social behaviour did not align with conventional DSM-5 diagnostic labels.”
Traditionally, psychiatric neuroimaging compares a clinical group to a healthy control group to search for biomarkers—objective biological measures linked to symptoms. This biomarker search has produced few consistent findings. The current study, which enrolled 179 participants across three sites (CAMH in Toronto; Zucker Hillside Hospital in New York; and the Maryland Psychiatric Research Center in Baltimore), challenges that case-control paradigm by showing that people with the same clinical diagnosis do not necessarily share the same neural profile.
Participants completed a facial imitation task while undergoing functional MRI. Using hierarchical clustering on task-related brain activity, the research team identified three distinct “activation profiles,” according to first author Dr. Colin Hawco of CAMH. These profiles can be summarized as typical activators, over-activated (hyperactivating) participants, and de-activating (hypoactivating) participants.
“The over-activated group appears to be less efficient: they likely exert more neural effort to perform the same task as others,” explains Dr. Hawco. “By contrast, the de-activating group showed patterns consistent with efficient neural processing and also achieved higher scores on behavioural measures of social cognition.” Crucially, all three profiles included participants both with and without schizophrenia.
Dr. Anil Malhotra, Director of Research at Zucker Hillside Hospital, emphasizes the clinical importance: “We currently lack effective treatments specifically targeting social impairments. By identifying brain-network-based subgroups, we can shift toward testing interventions that change neural function directly, rather than relying only on symptom reports.”
Social impairments can make it hard for people to interpret and respond to emotions such as fear, sadness, or happiness in others. As these impairments worsen, affected individuals are more likely to experience social isolation, reduced daily functioning, and a lower quality of life, notes Dr. Robert Buchanan, Director of the Maryland Psychiatric Research Center, who has pursued new treatments to improve social function for decades.
To validate their findings, the authors repeated the clustering analysis in an independent replication sample of 108 participants. The replication reproduced the same three neural activation patterns, strengthening confidence that these profiles are reliable and not tied to a single research site or diagnostic label.
Funding: The study is part of the Social Processes Initiative in Neurobiology of the Schizophrenia(s) (SPINS) and was funded by the National Institute of Mental Health under its Research Domain Criteria (RDoC) initiative.
Source: CAMH
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Original Research: Abstract for “Separable and Replicable Neural Strategies During Social Brain Function in People With and Without Severe Mental Illness” by Colin Hawco et al., American Journal of Psychiatry. Published January 4, 2019.
doi: 10.1176/appi.ajp.2018.17091020
MLA: CAMH. “Brains of People With Schizophrenia Related Disorders Aren’t All the Same.” NeuroscienceNews, 4 January 2019.
APA: CAMH (2019, January 4). Brains of People With Schizophrenia Related Disorders Aren’t All the Same. NeuroscienceNews.
Chicago: CAMH. “Brains of People With Schizophrenia Related Disorders Aren’t All the Same.” NeuroscienceNews. (accessed January 4, 2019).
Abstract
Separable and Replicable Neural Strategies During Social Brain Function in People With and Without Severe Mental Illness
Objective:
Conventional case-control designs and clinical heterogeneity can hinder biomarker discovery in brain disorders. The authors applied hierarchical clustering to task-evoked neural activity during a facial imitation/observation fMRI task to identify biologically or behaviourally defined subgroups, independent of diagnostic categories.
Methods:
The Social Processes Initiative in Neurobiology of the Schizophrenia(s) (SPINS) study included 179 participants (109 with a schizophrenia spectrum disorder and 70 healthy controls) across three sites. Hierarchical clustering identified data-driven participant groups based on neural activation patterns. The groups were compared on social and neurocognitive measures administered outside the scanner.
Results:
Three clusters with distinct neural activation patterns emerged. Cluster membership did not depend on diagnostic category or scan site. The largest cluster showed canonical activation in the simulation network (“typical activators”); the other clusters were characterized by hyperactivation and deactivation. Within-cluster distances were smaller than distances defined by diagnosis or site. The deactivating cluster showed the highest social cognitive and general neurocognitive scores. A replication sample (N=108; including schizophrenia spectrum disorder, euthymic bipolar disorder, and healthy control participants) reproduced the three-cluster pattern.
Conclusions:
These results demonstrate reproducible, distinct neural strategies during a socio-emotional task that are independent of DSM diagnosis or scan location. The identified subgroups may serve as objective neuroimaging endpoints for target-engagement studies aiming to enhance cognitive and social functioning regardless of diagnostic category.