New research uncovers how behavioral variant frontotemporal dementia (bvFTD) alters empathy processing, with advanced imaging revealing profound disruptions in the brain regions responsible for understanding and responding to others’ pain.
Study: Altered Empathy Processing in Frontotemporal Dementia. Image Credit: Chinnapong / Shutterstock.com
A recent study published in JAMA Network Open utilizes advanced imaging technologies to measure alterations in empathy to pain in patients with behavioral variant frontotemporal dementia (bvFTD).
The neurology of empathy
Empathy refers to the ability of an individual to perceive, be sensitive to, and care about the emotional well-being of others. Various regions within the brain are involved in empathy, including mirror neurons, the anterior insular and medial prefrontal cortices, the amygdala, the basal ganglia, the anterior cingulate cortex, and the orbitofrontal cortex.
Loss of empathy is a characteristic feature of bvFTD, which can cause affected individuals to lack consideration for others and the ability to respond to the concerns of loved ones. In severe cases, bvFTD can lead to questionable moral behaviors that can negatively affect their ability to form and sustain relationships.
Previous research suggests that the lack of empathy in bvFTD arises due to the impaired functioning of frontoinsular and temporal neuronal structures that are essential for processing social information. Furthermore, bvFTD has been shown to directly affect the ventromedial prefrontal cortex, which is primarily responsible for regulating complex emotions, controlling impulsive behaviors, and making moral judgments.
About the study
In the current study, 28 patients with bvFTD were compared with an equal number of controls with normal cognitive function in a classical case-control study. Patients and controls were similar in their median ages at 66.7 and 67.6 years, respectively, as well as their educational attainment distribution.
The current study was conducted across three centers in Stockholm, Sweden. The Interpersonal Reactivity Index (IRI) was used to assess empathy by measuring its cognitive and affective aspects.
Task-based functional magnetic resonance imaging (fMRI) was used to monitor any changes in brain activity in controls and cases.
Subtraction techniques were used to eliminate the blood oxygen level-dependent (BOLD) signal at baseline from the signal in the pain condition. This allowed the researchers to isolate the brain responses related to empathy for pain (EFP).
Two regions of interest (ROIs) were selected: one based on a meta-analysis of areas frequently reported to be activated during EFP and the other based on the activation pattern observed in controls during EFP (CA-ROI). CA-ROI was used to examine associations with empathy-related responses, as this region exhibited normal activation patterns in this task.
Reduced empathy signal in bvFTD
The BOLD signal during EFP was increased in only two areas in bvFTD patients compared to 12 areas in controls. The BOLD signal was reduced under the ROI related to affective empathy, with the average change during EFP about 21% for controls as compared to -1.3% for cases. However, no reduction in the BOLD signal was observed under the cognitive empathy ROI.
The EPF-BOLD signal in the CA-ROI was increased in control participants who reported a higher self-perception of empathic feelings in the IRI. Among bvFTD patients, the signal for EPF was positively correlated with the informants’ ratings of the patients’ empathic concerns. Thus, according to others, the higher this signal, the more likely the patient was to have empathic feelings.
Conclusions
The fMRI findings in the current task-based study of empathy for pain among fvFTD cases showed reduced responses in brain regions key to processing empathic feelings. This change reflects an early impact of the various changes in neuronal structure and function that occur in bvFTD.
The magnitude of empathy-related neural activity was correlated with the patients’ ability to experience empathy, as judged by the individuals living with the patients affected by bvFTD.”
The current study used multiple devices for fMRI, which may have introduced variability in the outcomes. An additional limitation of the current study involved the inclusion of patients with both sporadic and genetic bvFTD. Furthermore, bvFTD diagnoses were clinical, without neuropathological confirmation.
Journal references:
- Mendez, M. F., Akhlaghipour, G., Jiminez, E. E. (2021). Empathy and Impaired Socioemotional Self-Perception in Frontotemporal Dementia. The Journal of Neuropsychiatry and Clinical Neurosciences 34(2). doi:10.1176/appi.neuropsych.21040099.
- Lindbergh, O., Li, T., Vestberg, S., et al. (2024). Altered Empathy Processing in Frontotemporal Dementia. JAMA Network Open. doi:10.1001/jamanetworkopen.2024.48601.
