I, robot: depression plays different roles in human-human and human-robot interactions

Aberrant social reward dynamics in individuals with melancholic major depressive disorder: An ERP study

BACKGROUND

Compared to monetary rewards, depressive symptoms are specifically associated with abnormal social reward processing. In addition, individuals with melancholic depression may exhibit more significant reward-related impairments. However, there is still limited understanding of the specific alterations in social reward processing in individuals with melancholic depression.

METHODS

Forty patients with melancholic major depressive disorder (MDD), forty patients with non-melancholic MDD, and fifty healthy controls participated in the social incentive delay (SID) tasks with event-related potential (ERP) recording. We measured one anticipatory ERP(cue-N2) and two consummatory ERPs (FRN, fb-P3). Furthermore, we examined correlation between FRN and consummatory anhedonia.

RESULTS

Melancholic MDD patients showed less anticipation of social rewards (cue-N2). Concurrently, melancholic individuals demonstrated diminished reception of social rewards, as evidenced by reduced amplitudes of FRN. Notably, the group x condition interaction effect on FRN was significant (F (2, 127) = 4.15, p = 0.018, η2ρ = 0.061). Melancholic MDD patients had similar neural responses to both gain and neutral feedback (blunted reward positivity), whereas non-melancholic MDD patients (t (39) = 3.09, p = 0.004) and healthy participants (t (49) = 5.25, p < 0.001) had smaller FRN amplitudes when receiving gain feedback relative to neutral feedback. In addition, there was a significant correlation between FRN and consummatory anhedonia in MDD patients.

CONCLUSIONS

Our findings indicated that individuals with melancholic MDD exhibit attenuated neural responses to both anticipated and consumed social rewards. This suggests that aberrant processing of social rewards could serve as a potential biomarker for melancholic MDD.

Aberrant high-beta band functional connectivity during reward processing in melancholic major depressive disorder: An MEG study

OBJECTIVE

To identify the spatial-temporal pattern variation of whole-brain functional connectivity (FC) during reward processing in melancholic major depressive disorder (MDD) patients, and to determine the clinical correlates of connectomic differences.

METHODS

61 MDD patients and 32 healthy controls were enrolled into the study. During magnetoencephalography (MEG) scanning, all participants completed the facial emotion recognition task. The MDD patients were further divided into two groups: melancholic (n = 31) and non-melancholic (n = 30), based on the Mini International Neuropsychiatric Interview (M.I.N.I.) assessment. Melancholic symptoms were examined by using the 6-item melancholia subscale from the Hamilton Depression Rating Scale (HAM-D6). The whole-brain orthogonalized power envelope connections in the high-beta band (20-35 Hz) were constructed in each period after the happy emotional stimuli (0-200 ms, 100-300 ms, 200-400 ms, 300-500 ms, and 400-600 ms). Then, the network-based statistic (NBS) was used to determine the specific abnormal connection patterns in melancholic MDD patients.

RESULTS

The NBS identified a sub-network difference at the mid-late period (300-500 ms) in response to happy faces among the three groups (corrected P = 0.035). Then, the post hoc and correlation analyses found five FCs were decreased in melancholic MDD patients and were related to HAM-D6 score, including FCs of left fusiform gyrus-right orbital inferior frontal gyrus (r = -0.52, P < 0.001), left fusiform gyrus-left amygdala (r = -0.26, P = 0.049), left posterior cingulate gyrus-right precuneus (r = -0.32, P = 0.025), left precuneus-right precuneus (r = -0.27, P = 0.049), and left precuneus-left inferior occipital gyrus (r = -0.32, P = 0.025).

CONCLUSION

In response to happy faces, melancholic MDD patients demonstrated a disrupted functional connective pattern (20-35 Hz, 300-500 ms), which involved brain regions in visual information processing and the limbic system. The aberrant functional connective pattern in reward processing might be a biomarker of melancholic MDD.

Psychological and Brain Responses to Artificial Intelligence's Violation of Community Ethics

Human moral reactions to artificial intelligence (AI) agents' behavior constitute an important aspect of modern-day human-AI relationships. Although previous studies have mainly focused on autonomy ethics, this study investigates how individuals judge AI agents' violations of community ethics (including betrayals and subversions) compared with human violations. Participants' behavioral responses, event-related potentials (ERPs), and individual differences were assessed. Behavioral findings reveal that participants rated AI agents' community-violating actions less morally negative than human transgressions, possibly because AI agents are commonly perceived as having less agency than human adults. The ERP N1 component showed the same pattern with moral rating scores, indicating the modulation effect of human-AI differences on initial moral intuitions. Moreover, the level of social withdrawal correlated with a smaller N1 in the human condition but not in the AI condition. The N2 and P2 components were sensitive to the difference between the loyalty/betrayal and authority/subversion domains but not human/AI differences. Individual levels of moral sense and autistic traits also influenced behavioral data, especially on the loyalty/betrayal domain. In our opinion, these findings offer insights for predicting moral responses to AI agents and guiding ethical AI development aligned with human moral values.

Fear of negative evaluation modulates the processing of social evaluative feedback with different valence and contexts

Fear of negative evaluation (FNE) is a susceptible and maintaining factor of social anxiety disorders. However, the question, how people process negative evaluation is influenced by individual differences in FNE, is poorly understood. To clarify the habitual processing characteristics of individuals with different levels of FNE, electroencephalography was recorded when two groups of participants with high FNE (hFNE) and low FNE (lFNE) performed a social evaluation perception task in which the feedback context/source (human vs. a computer) and valence (thumb-up/like vs. thumb-down/dislike) were manipulated. We found effects of feedback source and valence on N1, P2, and P3, which reflect early attention, integrated perception, and elaborative processing, respectively, as well as general reward effects on reward positivity (RewP) across contexts. Importantly, compared to the lFNE group, the hFNE group showed larger midfrontal N1 and theta oscillation in response to negative feedback indicating dislike (vs. like), and also showed larger P3. These findings suggest that individuals with hFNE are more attentional vigilance to negative (vs. positive) social feedback, implying that individuals with different levels of FNE assign different implicit threat values to social-evaluation threat stimuli.