Tracking Deceased-Related Thinking With Neural Pattern Decoding of a Cortical-Basal Ganglia Circuit

Abstract

Background Deceased-related thinking is central to grieving and potentially critical to processing of the loss. Self-report measurements might fail to capture important elements of deceased-related thinking and processing. Here, we used a machine learning approach applied to fMRI - known as neural decoding - to develop a measure of ongoing deceased-related processing. Methods 23 subjects grieving the loss of a first-degree relative, spouse or partner within 14 months underwent two fMRI tasks. They first viewed pictures and stories related to the deceased, a living control and a demographic control figure while providing ongoing valence and arousal ratings. Second, they performed a 10-minute Sustained Attention to Response Task (SART) with thought probes every 25–35 seconds to identify deceased, living and self-related thoughts. Results A conjunction analysis, controlling for valence/arousal, identified neural clusters in basal ganglia, orbital prefrontal cortex and insula associated with both types of deceased-related stimuli vs. the two control conditions in the first task. This pattern was applied to fMRI data collected during the SART, and discriminated deceased-related but not living or self-related thoughts, independently of grief-severity and time since loss. Deceased-related thoughts on the SART correlated with self-reported avoidance. The neural model predicted avoidance over and above deceased-related thoughts. Conclusions A neural pattern trained to identify mental representations of the deceased tracked deceased-related thinking during a sustained attention task and also predicted subject-level avoidance. This approach provides a new imaging tool to be used as an index of processing the deceased for future studies of complicated grief.

Ongoing monitoring of mindwandering in avoidant grief through cortico-basal-ganglia interactions

“…Thoughts of loss arising during mindwandering can be predicted by activation of a neural d-MR network. Moreover, avoidant grievers experience more intense activation of these representations and subsequently more frequent thoughts of loss (Schneck et al , 2017). These findings suggest that mental representations contribute to thoughts of loss and that avoidant grievers attempt to suppress these representations, ironically increasing their salience and frequency.…”

“…d-MR comprises the abstract symbol for the deceased that exists independently of a specific perceptual or cognitive modality (Schneck et al , 2017). We sought to delineate a neural model for d-MR incorporating across visual, memory and relational representations of the deceased.…”

Increased Amygdala Activations during the Emotional Experience of Death-Related Pictures in Complicated Grief: An fMRI Study

“…Individuals with perinatal grief also showed hyperactivation of frontal areas while viewing pictures of healthy infants [50]. Recently, their activation was recorded during the processing of affective stimuli related to the deceased [21], and activation in the putamen, caudate nucleus, insula, and orbitofrontal cortex was observed when grieving persons were thinking about the deceased [23]. These areas are thought to be involved in the processing of economic gains and losses and in the management of rewards and reinforcers, among other functions [51].…”

“…Limitations of fMRI studies of grieving individuals to date include the absence of a CG diagnosis in some investigations (e.g., [18,22,23]). Furthermore, the response to affective autobiographical stimuli related to the deceased person is frequently compared with the response to a neutral condition alone (e.g., [18,19,23]).…”

“…Limitations of fMRI studies of grieving individuals to date include the absence of a CG diagnosis in some investigations (e.g., [18,22,23]). Furthermore, the response to affective autobiographical stimuli related to the deceased person is frequently compared with the response to a neutral condition alone (e.g., [18,19,23]). Although exposure to this type of material appears to increase emotional reactivity [24], behavioral studies have also observed emotional alterations in response to other types of pleasant or unpleasant stimuli in individuals with CG [6,9,16].…”