Impairments of Implicit Emotional Neurocognitive Processing in College Students With Subthreshold Depression: An ERP Study

State-dependent alterations of implicit emotional dominance during binocular rivalry in subthreshold depression

Binocular rivalry, a visual perception phenomenon where two or more percepts alternate every few seconds when distinct stimuli are presented to the two eyes, has been reported as a biomarker in several psychiatric disorders. It is unclear whether abnormalities of binocular rivalry in depression could occur when emotional rivaling stimuli are used, and if so, whether an emotional binocular rivalry test could provide a trait-dependent or state-dependent biomarker. In the current study, 34 individuals with subthreshold depression and 31 non-depressed individuals performed a binocular rivalry task associated with implicit emotional processing. Participants were required to report their perceived orientations of the rival gratings in the foreground and to neglect emotional face stimuli in the background. The participants were retested after an approximately 4-month time interval. Compared to the non-depressed group, the subthreshold depression group showed significantly longer perceptual dominance durations of the grating with emotional faces as the background (i.e., implicit emotional dominance) at the initial assessment. However, the abnormality was not found at the follow-up assessment. More importantly, we found smaller changes in depressive severity at the follow-up assessment for individuals displaying longer emotional dominance at the initial assessment than for individuals with weaker emotional dominance. The current emotional binocular rivalry test may provide an objective, state-dependent biomarker for distinguishing individuals with subthreshold depression from non-depressed individuals.

Differences in cognitive processing between snakes and guns: Evidence from electroencephalography

The aim of the study is to explore differences in cognitive processing of phylogenetic and ontogenetic stimulus using the electroencephalography (EEG) technology. The researcher chose snakes and guns as representatives of phylogenetic stimulus and ontogenetic stimulus, respectively, and used the Oddball paradigm to present the experimental stimuli and explore the cognitive processing differences between them through time-domain analysis and time-frequency analysis. The results of time-domain analysis showed that snakes elicited larger N1, P2, and P3 amplitudes and a shorter P3 latency than guns and neutral stimuli, and that guns elicited greater P2 and P3 amplitudes than neutral stimuli. The findings of time-frequency analysis showed that the beta-band (320 - 420 ms, 25 - 35 Hz) power elicited by snakes was significantly greater than by guns and neutral stimuli, and that the beta-band power elicited by guns was significantly greater than by neutral stimuli. The results indicated that the brain has a cognitive processing advantage for both snakes and guns, which is more obvious for snakes than for guns, and that the brain is more sensitive to snakes.

Utilization of passive visual perception task indetecting patients with major depressive disorder for active health

Depression is a common emotional and mental disease. At present, doctors' diagnosis mainly depends on the existing evaluation scales and their accumulated experience, lack of objective electrophysiological quantitative evaluation indicators. This study explores the difference in event-related potential (ERP) between patients with depression and healthy controls under the stimulation of multi-dimensional tasks, extracts the characteristic data, and uses a t-test for statistical analysis to provide an objective evaluation index for the clinical diagnosis of depression. Ninety-nine patients in the major depression group (MDD) and thirty patients in the healthy control group (HC) were used to compare the responses to positive, negative, and neutral stimulation, the results showed that there were significant differences between the left and right occipital lobes and one frontal lobe, and the frontal lobe showed lateralization; There were significant differences between the depression group and the healthy control group under multi-dimensional stimulation (P < 0.01), and the depression patients were significantly lower than the healthy patients. The results showed that emotional information was processed differently in patients with depression in the early stages of visual face processing. Therefore, EEG indices could be used as an objective index for the early detection of depression. Moreover, according to the instructions before the test, the subject is only asked to recognize visual pictures instead report emotional feelings. Stigma about psychiatric disorders could thus be reduced in this way. The explorations above facilitate designing more accurate and implicit active mental health techniques.

The Neural Correlates of the Abnormal Implicit Self-Esteem in Major Depressive Disorder: An Event-Related Potential Study

Implicit self-esteem (ISE) has been considered a critical factor in the development and maintenance of major depressive disorder (MDD). Further investigating the event-related potential (ERP) characteristics underlying abnormal ISE in MDD would be helpful for understanding the neural mechanism of MDD. For this purpose, 32 MDD patients and 31 age- and sex-matched healthy controls (HCs) were enrolled in this study. The Rosenberg Self-Esteem Scale (RSES) was used to evaluate explicit self-esteem (ESE), and a self-esteem go/no-go association task (GNAT) was used to assess ISE. Electroencephalograms were synchronously recorded when performing the self-esteem GNAT. Behavioral data and ERP characteristics under different conditions were analyzed and compared within and across groups. The results showed that compared to HCs, MDD patients had significantly lower RSES scores and self-D scores of GNAT, which reflected lower levels of ESE and ISE, respectively. No significant correlation was found between RESE and self-D scores, and only RESE scores were significantly negatively correlated with the Hamilton Depression Rating Scale (HAMD) score. The averaged centroparietal go-P3 amplitude under the self-positive condition was significantly smaller in MDD than in HCs. Moreover, HCs had a significantly larger average centroparietal go-P3 amplitude in self-positive than in self-negative conditions, while this pattern was opposite in the MDD group. The neural activity patterns for other conditions were similar between MDD and HCs. Our results suggested that patients with MDD have a decreased level of both ESE and ISE, and ISE might be more independent of clinical symptoms. Decreased neural processing that implicitly associate self with positive conditions (and relatively increased implicit association between self and negative conditions) might be important neural correlates for abnormal ISE in MDD.