Summary: For the first time in Veterans, researchers have identified brain regions activated during subconscious associations between the self and suicide-related concepts using the Suicide Implicit Association Test (S-IAT). These brain areas are part of networks responsible for self-processing and identifying significant stimuli, offering potential targets for future treatment.
The study, conducted with fMRI scans, found distinct patterns of brain activation when participants linked “me” with “death” compared to other associations. This work advances our understanding of the neural mechanisms behind suicidality and could inform interventions like neurofeedback or brain stimulation.
Key Facts:
- Brain Activation Identified: fMRI revealed unique neural activation when Veterans made subconscious self-death associations.
- Suicide-Specific Cognition: The S-IAT uniquely measured implicit suicidal thoughts, offering a direct way to assess risk-related brain circuits.
- Clinical Implications: Findings open the door to targeting these brain areas with treatments like neurofeedback or pharmacotherapy to reduce suicide risk.
Source: Boston University
Implicit Association Tests (IATs) are computerized tests that can be used to assess the subconscious association between different concepts. A form of the IAT, the Suicide Implicit Association Test (S-IAT), can measure people’s associations between the “self” and concepts relating to death/dying/suicide.
While S-IAT is one of the few tests that uniquely predicts future suicide risk, there has been limited research investigating brain activation related to the S-IAT.
For the first time in a Veteran population, researchers have identified several brain regions that were sensitive to self-death associations. These brain regions are a part of brain networks that are involved in identifying important stimuli in our environment and processing information as it relates to our “self”.
The results from this study mark an important step towards characterizing neural mechanisms that contribute to suicidality.
“Currently, there is no consensus on what neural mechanisms contribute to suicide risk, so observing brain activation related to the S-IAT could lead to a breakthrough in our understanding the underlying neural mechanisms of suicide risk,” explains corresponding author Audreyana Jagger-Rickels, PhD, assistant professor of psychiatry at Boston University Chobanian & Avedisian School of Medicine.
Forty-two post-9/11 Veterans at low risk for suicide completed S-IAT concurrently with functional magnetic resonance imaging (fMRI) – a neuroimaging technique that measures brain activity by detecting changes in blood flow. The S-IAT included a total of 20 target words; five words from each of these four word categories: Death, Life, Me, Not Me.
For each trial, one of the 20 target words was presented in the center of the screen. Simultaneously, on the top left and top right of the screen were two choices for categorizing the target word.
The participant categorized the target word in the center of the screen into one of the two categories at the top of the screen. In certain trials, participants categorized “death” and “me” words to the same side of the screen. These trials measured implicit self-death associations.
To identify brain activation related to self-death associations, the researchers then contrasted a participant making a self-death association compared to the brain activation when someone was not making a self-death association.
“The brain circuit that we identified could be a novel treatment target for suicidality. For instance, changing the activity of this brain circuit with techniques like neuro-feedback, brain stimulation, or pharmacotherapies could reduce suicide risk by targeting the brain circuit that underlies this suicide-specific cognition (self-death implicit association),” adds Jagger-Rickels who also is principal investigator in the National Center for PTSD at the VA Boston Healthcare System.
According to the researchers, one of the challenges in identifying brain circuits related to suicide is that we are often indirectly relating some brain pattern to a patient’s history or reported symptoms related to suicide.
While this type of analysis is informative, it does not tell us how the brain activates to initiate or sustain suicidal thoughts and behaviors. As a result, identifying brain circuits related to suicide risk has been limited as we can identify brain regions associated with suicide risk but not how they are contributing to suicide risk.
“Using measures like the S-IAT, which measures a suicide-specific cognition, will not only help us identify brain mechanisms that underlie suicidality but also how they contribute to suicidality. In turn, this may also aid in the development of novel treatments targeting the brain mechanisms underlying suicidal thoughts and behaviors.”
About this neuroscience and mental health research news
Author: Gina DiGravio
Source: Boston University
Contact: Gina DiGravio – Boston University
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Brain Activation During Suicide-Specific Cognition in Trauma-Exposed Veterans” by Audreyana Jagger-Rickels et al. Suicide and Life-Threatening Behavior
Abstract
Brain Activation During Suicide-Specific Cognition in Trauma-Exposed Veterans
Introduction
The suicide Implicit Association Test (S-IAT) captures the strength of the implicit identification between self and death and is one of the few suicide-specific behavioral tasks that uniquely predicts future suicide risk. Thus, identifying brain regions associated with the S-IAT provides insights into the neural mechanisms underlying suicidality.
Methods
This study measured brain activation during the S-IAT with concurrent fMRI in a post-9/11 trauma-exposed veteran sample. In total, 37 post-9/11 veterans at low risk for suicide participated in this study as part of an ongoing longitudinal study.
Results
Behaviorally, participants were slower to categorize words during incongruent (death-me) contexts relative to congruent (life-me) contexts (p < 0.001). Whole-brain voxelwise fMRI contrasts revealed a brain network that was significantly more active during incongruent trials than congruent trials that included the bilateral occipital, posterior parietal, and cerebellum (corrected p < 0.05). This increased brain activation corresponded with task performance, suggesting that more brain resources are needed to complete death-me identifications.
Conclusions
These results suggest that death-me implicit identifications involve resolving conflict between self and death representations in the brain and mark an important step towards characterizing neural mechanisms contributing to suicidality.
