Boosting interpersonal emotion regulation through facial imitation: functional neuroimaging foundations.

Empathic function, which is primarily manifested by facial imitation, is believed to play a pivotal role in interpersonal emotion regulation for mood reinstatement. To explore this association and its neural substrates, we performed a questionnaire survey (study l) to identify the relationship between empathy and interpersonal emotion regulation; and a task-mode fMRI study (study 2) to explore how facial imitation, as a fundamental component of empathic processes, promotes the interpersonal emotion regulation effect. Study 1 showed that affective empathy was positively correlated with interpersonal emotion regulation. Study 2 showed smaller negative emotions in facial imitation interpersonal emotion regulation (subjects imitated experimenter's smile while followed the interpersonal emotion regulation guidance) than in normal interpersonal emotion regulation (subjects followed the interpersonal emotion regulation guidance) and Watch conditions. Mirror neural system (e.g. inferior frontal gyrus and inferior parietal lobe) and empathy network exhibited greater activations in facial imitation interpersonal emotion regulation compared with normal interpersonal emotion regulation condition. Moreover, facial imitation interpersonal emotion regulation compared with normal interpersonal emotion regulation exhibited increased functional coupling from mirror neural system to empathic and affective networks during interpersonal emotion regulation. Furthermore, the connectivity of the right orbital inferior frontal gyrus-rolandic operculum lobe mediated the association between the accuracy of facial imitation and the interpersonal emotion regulation effect. These results show that the interpersonal emotion regulation effect can be enhanced by the target's facial imitation through increased functional coupling from mirror neural system to empathic and affective neural networks.

Relationship Between Age and Cerebral Hemodynamic Response to Breath Holding: A Functional Near-Infrared Spectroscopy Study.

Cerebrovascular reactivity (CVR) is routinely measured as a predictor of stroke in people with a high risk of ischemic attack. Neuroimaging techniques such as emission tomography, magnetic resonance imaging, and transcranial doppler are frequently used to measure CVR even though each technique has its limitations. Functional near-infrared spectroscopy (fNIRS), also based on the principle of neurovascular coupling, is relatively inexpensive, portable, and allows for the quantification of oxy- and deoxy-hemoglobin concentration changes at a high temporal resolution. This study examines the relationship between age and CVR using fNIRS in 45 young healthy adult participants aged 18-41 years (6 females, 26.64 ± 5.49 years) performing a simple breath holding task. Eighteen of the 45 participants were scanned again after a week to evaluate the feasibility of fNIRS in reliably measuring CVR. Results indicate (a) a negative relationship between age and hemodynamic measures of breath holding task in the sensorimotor cortex of 45 individuals and (b) widespread positive coactivation within medial sensorimotor regions and between medial sensorimotor regions with supplementary motor area and prefrontal cortex during breath holding with increasing age. The intraclass correlation coefficient (ICC) indicated only a low to fair/good reliability of the breath hold hemodynamic measures from sensorimotor and prefrontal cortices. However, the average hemodynamic response to breath holding from the two sessions were found to be temporally and spatially in correspondence. Future improvements in the sensitivity and reliability of fNIRS metrics could facilitate fNIRS-based assessment of cerebrovascular function as a potential clinical tool.

Task-Based and Resting-State Cortical Functional Differences After Spinal Cord Injury: A Pilot Functional Near-Infrared Spectroscopy Study.

Brain reorganization following spinal cord injury (SCI) has been well-established using animal and human studies. Yet, much is unknown regarding functional recovery and adverse secondary outcomes after SCI. Functional near-infrared spectroscopy (fNIRS) is a neuroimaging technique that offers methodological flexibility in a real-world setting. We used fNIRS to examine the cortical functional differences between 12 males with thoracolumbar SCI (46.41 ± 11.09 years of age) and 12 healthy males (47.61 ± 11.94 years of age) during resting state and task conditions-bilateral finger tapping (FT), mental imagery of bilateral FT with action observation (FTI+AO), and bilateral ankle tapping (AT). We found an overall decrease in hemodynamic response of the SCI group during all three task conditions. Task modulated functional connectivity (FC) computed using beta series correlation technique was compared using independent sample t-tests at α = 0.05. Connectivity between the right mediolateral sensorimotor network (SMN) and the right medial SMN was reduced during the FT task in SCI. A mixed analysis of variance revealed that the FC within the right mediolateral SMN was reduced during FT but preserved during FTI+AO (i.e., comparable to controls) in the SCI group. Lower FC of these regions was associated with longer injury durations. Additionally, we found a general decrease in resting state FC of the SCI group, specifically in the Slow-3 frequency range (0.073 to 0.1 Hz). These results, though preliminary, are consistent with past studies and highlight the potential of fNIRS in SCI and rehabilitative research.