Results from recent functional neuroimaging studies suggest that facial expressions of pain trigger empathic mimicry responses in the observer, in the sense of an activation in the pain matrix. However, pain itself also signals a potential threat in the environment and urges individuals to escape or avoid its source. This evolutionarily primitive aspect of pain processing, i.e., avoidance from the threat value of pain, seems to conflict with the emergence of empathic concern, i.e., a motivation to approach toward the other. The present study explored whether the affective values of targets influence the detection of pain at the unconscious level. We found that the detection of pain was facilitated by unconscious negative affective processing rather than by positive affective processing. This suggests that detection of pain is primarily influenced by its inherent threat value, and that empathy and empathic concern may not rely on a simple reflexive resonance as generally thought. The results of this study provide a deeper understanding of how fundamental the unconscious detection of pain is to the processes involved in the experience of empathy and sympathy.

Background: The putative neural bases of affected episodic memory and emotional recognition in early Alzheimer’s disease are suspected to be limbic and paralimbic pathological processes. The uncinate fasciculus (UF) is especially considered to be a critical structure. In the present study, we investigated microstructural UF pathology by diffusion tensor imaging in the subjects with amnestic mild cognitive impairment (aMCI), and its association with memory and emotional processing impairment. Methods: Subjects included 16 patients with aMCI and 16 healthy individuals. Diffusion tensor images were acquired and the fractional anisotropy (FA) of the UF was calculated. In addition, its association with verbal memory and emotional facial recognition was investigated. Results: The FA values of the left UF were significantly lower in aMCI, and strongly correlated with episodic memory performance in aMCI. For the emotional recognition task, the aMCI subjects performed worse in negative emotion recognitions. The FA values of the left UF were correlated with the performance of fearful facial expression recognition in aMCI. Conclusion: These results indicated that microstructural alterations of the UF had already occurred in aMCI. In addition, these alterations could be one of the causes of memory and emotional processing impairment in aMCI.

The limited efficacy of available antidepressant therapies may be due to how they affect the underlying brain network. The purpose of this study was to develop a melancholic MDD biomarker to identify critically important functional connections (FCs), and explore their association to treatments. Resting state fMRI data of 130 individuals (65 melancholic major depressive disorder (MDD) patients, 65 healthy controls) were included to build a melancholic MDD classifier, and 10 FCs were selected by our sparse machine learning algorithm. This biomarker generalized to a drug-free independent cohort of melancholic MDD, and did not generalize to other MDD subtypes or other psychiatric disorders. Moreover, we found that antidepressants had a heterogeneous effect on the identified FCs of 25 melancholic MDDs. In particular, it did impact the FC between left dorsolateral prefrontal cortex (DLPFC)/inferior frontal gyrus (IFG) and posterior cingulate cortex (PCC)/precuneus, ranked as the second ‘most important’ FC based on the biomarker weights, whilst other eight FCs were normalized. Given that left DLPFC has been proposed as an explicit target of depression treatments, this suggest that the limited efficacy of antidepressants might be compensated by combining therapies with targeted treatment as an optimized approach in the future.

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This study revealed that prefrontal Aβ deposition correlates with apathy.