Impairment of response inhibition to emotional face stimuli in individuals with subclinical depression

Pupillary response to cognitive control in depression-prone individuals

Revealing the pupillary correlates of depression-prone individuals is conducive to the early intervention and treatment of depression. This study recruited 31 depression-prone and 31 healthy individuals. They completed an emotional task-switching task combined with a go/no-go task, and task-evoked pupillary responses (TEPR) were recorded. Behavioral results showed no significant differences in behavioral performance in terms of cognitive flexibility and inhibition between the depression-prone group and the healthy control group. The pupillary results revealed that (1) the depression-prone group showed slightly lower TEPRs to positive stimuli than the healthy controls during cue presentation; (2) during target presentation, the depression-prone group did not show an effect of emotional valence on the pupillary response in the task-repeat trials; and (3) compared to the healthy controls, the depression-prone group showed significantly smaller TEPRs to negative no-go stimuli and had a longer latency of the second peak of pupil dilation in no-go trials. These results imply that depression-prone individuals may have slower neural responses in cognitive control tasks and emotion-specific weakened cognitive control than healthy individuals.

Enhancing response inhibition behavior through tDCS intervention in college students with smartphone addiction

Smartphone addiction, emerging from excessive use of smartphones, poses a challenge to inhibitory control functions within society. This research employed transcranial direct current stimulation (tDCS) as an intervention alongside the stop signal task (SST) to explore behavioral distinctions between individuals with smartphone addiction and a non-addicted control group, focusing on the efficacy of tDCS intervention. The participant cohort comprised 80 individuals, divided into an addiction group (39 participants, with 19 receiving active tDCS and 20 receiving sham tDCS) and a control group (41 participants, with 20 receiving active tDCS and 21 receiving sham tDCS), with anodal stimulation applied over the right dorsolateral prefrontal cortex (dlPFC) and cathodal placement over the left arm. The findings indicate that university students struggling with smartphone addiction exhibit reduced inhibitory control compared to their non-addicted peers, while maintaining similar levels of general cognitive control. Remarkably, tDCS interventions were observed to enhance inhibitory control in both groups. Although the improvement in the addiction group appeared more pronounced numerically than in the control group, no significant interaction with group was noted. However, a higher percentage of participants in the smartphone addiction (SA) group exhibited enhanced response inhibition under active tDCS. This study demonstrates the inhibitory control deficits in individuals addicted to smartphones and underscores the potential of tDCS in enhancing response inhibition. It provides a valuable reference for future tDCS research targeting smartphone addiction and highlights the importance of developing healthier smartphone usage habits.

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.

The impact of emotional stimuli on response inhibition in an inpatient and day-hospital patient psychosomatic cohort

Objectives

To correctly recognize and respond to your counterpart's emotion is essential for a successful get-together. To ensure this, emotional processes and inhibitory control are linked and interact with each other. However, this interaction can be altered in several mental disorders. In a group of psychosomatic patients, we investigated possible differences in the response inhibition between neutral and emotional stimuli and whether a psychosomatic inpatient and day-hospital patient treatment influences response inhibition profiles.

Methods

One hundred and one patients, diagnosed with different psychiatric diagnoses (77 women, 41.43 ± 13.13 years), completed an emotional stop-signal task (ESST) and an impulsive behavior scale upon admission in an inpatient and day-hospital patient treatment on a psychosomatic ward (T0) and at discharge (T1). Patients with depressive disorders completed the test again after 1 year (follow-up measurement T2, n = 22). Emotional stimuli were angry and neutral faces. Stop-signal reaction time (SSRT) and stop-signal delay (SSD) were calculated as the main behavioral parameters.

Results

We found a significantly higher SSRT for neutral than angry faces at both admission (8.538 ms, p < 0.001) and discharge (11.142 ms, p < 0.001), with a matching higher SSD for angry than neutral faces at both timepoints (T0: 8.360 ms, p < 0.001, T1: (6.950 ms, p < 0.001). The SSRT for angry faces significantly decreased after treatment (-8.485 ms, p = 0.0110). For neutral faces, the decrease failed to reach significance (-5.881 ms, p = 0.250). A significant decrease in SSRT for neutral faces in patients with depressive disorders was found 1 year after discharge compared with admission (-19.040 ms, p = 0.0380).

Conclusion

Our data demonstrate a decreased response inhibition for neutral compared with emotional stimuli and an improved response inhibition for angry faces after discharge in a psychosomatic inpatient and day-hospital patient cohort. Additionally, patients with depressive disorders displayed a significantly better response inhibition for neutral faces 1 year after discharge compared with the baseline measurement. With this study, we provide more evidence for altered emotional response inhibition in different mental disorders and a hint that psychosomatic inpatient and day-hospital patient treatment may help to normalize it, even if the effects remained small and it needs further research to prove causality.

Negative inhibition is poor in sub-threshold depression individuals: Evidence from ERP and a Go/No-go task

In this study, Go/No-go task combined with ERP technology were used to explore the characteristics of negative emotion inhibition in SD and healthy individuals and whether there are differences between negative emotion inhibition and neutral emotion inhibition in SD. The results showed that SD showed the same poor negative inhibition as depressive patients in behavior, but there was no significant difference between SD and CG in ERPs. Overall, compared with neutral emotional information, negative emotional information would reduce attention control in conflict processing, lead to faster conflict processing, attract attention, occupy more cognitive resources, and be more difficult to inhibit. It is concluded that the negative attention bias of SD individuals is only reflected in the bottom-up stimulation processing, but has not developed into the top-down cognitive control, which also suggests that the corresponding intervention measures at the early stage of depression may have better effects.