Immediate and Differential Response to Emotional Stimuli Associated With Transcranial Direct Current Stimulation for Depression: A Visual-Search Task Pilot Study

OBJECTIVES

When administered in repeated daily doses, transcranial direct current stimulation (tDCS) directed to the prefrontal cortex has cumulative efficacy for the treatment of depression. Depression can be marked by altered processing of emotionally salient information. An acute marker of response to tDCS may be measured as an immediate change in emotional information processing. Using an easily administered web-based task, we tested immediate changes in emotional information processing in acute response to tDCS in participants with and without depression.

MATERIALS AND METHODS

We enrolled n = 21 women with mild-to-moderate depression and n = 20 controls without depression to complete a web-based visual search task before and after 30 minutes of tDCS directed to the prefrontal cortex. The timed task required participants to identify a target face among arrays showing sad, neutral, or mixed (distractor) expressions.

RESULTS

At baseline, as predicted, the participants with depression differed from those without in emotional processing speed (mean z score difference -0.66 ± 0.27, p = 0.022) and accuracy in identifying sad stimuli (error rate: 4.4% vs 1.8%, p = 0.039). In response to tDCS, the participants with depression became significantly faster on the distractor condition (pre- vs post-tDCS z scores: -0.45 ± 0.65 vs -0.85 ± 0.65, p = 0.009), suggesting a specific reduction in bias toward negative emotional information. In response to tDCS, the depressed group also had significant improvements in self-reported mood (increased happy, decreased sad and anxious mood).

CONCLUSIONS

Participants with depression vs those without were differentiated by their performance of the visual search task at baseline and in response to tDCS. Given that measurable effects on depression scales may require weeks of tDCS treatments, acute change in emotional information processing can serve as an easily obtainable marker of depression and its response to tDCS.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT05188248.

Age Differences in the Tradeoff between Proactive and Reactive Cognitive Control in Emotional Information Processing

Greater well-being in older adults stems from more effective emotion regulation strategies, highlighting the role of cognitive control. However, cognitive control involves different subsystems, and it is still unclear whether different subsystems have different effects on different emotional information processing. The Dual Mechanisms of Control (DMC) theory postulates that cognitive control can operate in two distinct modes, namely proactive control (a "proactive" preparatory mode) and reactive control (a "reactive" wait-and-see mode). This study created an emotional AX-CPT task to explore differences in cognitive control tradeoff between youth and older adults when processing emotional information. The results found that youth had significantly higher error rates on the emotional-neutral sequence than older adults regardless of the valence of emotional information; only in the negative condition did older adults have higher error rates on both the sad-sad and neutral-sad sequences than youth; this phenomenon was not found in the positive condition. The study showed that, in emotional information processing, youth preferred proactive control over older adults; in negative information processing, older adults preferred reactive control strategies over youth; in positive information processing, older adults showed a similar cognitive control pattern to youth, and proactive control was enhanced.

Emotional Intelligence Not Only Can Make Us Feel Negative, but Can Provide Cognitive Resources to Regulate It Effectively: An fMRI Study

Neuroscientists have formulated the model of emotional intelligence (EI) based on brain imaging findings of individual differences in EI. The main objective of our study was to operationalize the advantage of high EI individuals in emotional information processing and regulation both at behavioral and neural levels of investigation. We used a self-report measure and a cognitive reappraisal task to demonstrate the role of EI in emotional perception and regulation. Participants saw pictures with negative or neutral captions and shifted (reappraised) from negative context to neutral while we registered brain activation. Behavioral results showed that higher EI participants reported more unpleasant emotions. The Utilization of emotions scores negatively correlated with the valence ratings and the subjective difficulty of reappraisal. In the negative condition, we found activation in hippocampus (HC), parahippocampal gyrus, cingulate cortex, insula and superior temporal lobe. In the neutral context, we found elevated activation in vision-related areas and HC. During reappraisal (negative-neutral) condition, we found activation in the medial frontal gyrus, temporal areas, vision-related regions and in cingulate gyrus. We conclude that higher EI is associated with intensive affective experiences even if emotions are unpleasant. Strong skills in utilizing emotions enable one not to repress negative feelings but to use them as source of information. High EI individuals use effective cognitive processes such as directing attention to relevant details; have advantages in allocation of cognitive resources, in conceptualization of emotional scenes and in building emotional memories; they use visual cues, imagination and executive functions to regulate negative emotions effectively.

An Experimental Medicine Investigation of the Effects of Subacute Pramipexole Treatment on Emotional Information Processing in Healthy Volunteers

Treatment with the dopamine D2/D3 receptor agonist pramipexole has demonstrated promising clinical effects in patients with depression. However, the mechanisms through which pramipexole might alleviate depressive symptoms are currently not well understood. Conventional antidepressant drugs are thought to work by biasing the processing of emotional information in favour of positive relative to negative appraisal. In this study, we used an established experimental medicine assay to explore whether pramipexole treatment might have a similar effect. Employing a double-blind, parallel-group design, 40 healthy volunteers (aged 18 to 43 years, 50% female) were randomly allocated to 12 to 15 days of treatment with either pramipexole (at a peak daily dose of 1.0 mg pramipexole salt) or placebo. After treatment was established, emotional information processing was assessed on the neural level by measuring amygdala activity in response to positive and negative facial emotional expressions, using functional magnetic resonance imaging (MRI). In addition, behavioural measures of emotional information processing were collected at baseline and on drug, using an established computerized task battery, tapping into different cognitive domains. As predicted, pramipexole-treated participants, compared to those receiving placebo, showed decreased neural activity in response to negative (fearful) vs. positive (happy) facial expressions in bilateral amygdala. Contrary to our predictions, however, pramipexole treatment had no significant antidepressant-like effect on behavioural measures of emotional processing. This study provides the first experimental evidence that subacute pramipexole treatment in healthy volunteers modifies neural responses to emotional information in a manner that resembles the effects of conventional antidepressant drugs.

Processing of affective words in adolescent PTSD-Attentional bias toward social threat

Post-traumatic stress disorder (PTSD) is associated with a hypersensitivity to potential threat. This hypersensitivity manifests through differential patterns of emotional information processing and has been demonstrated in behavioral and neurophysiological experimental paradigms. However, the majority of research has been focused on adult patients with PTSD. To examine possible differences in underlying neurophysiological patterns for adolescent patients with PTSD after childhood sexual and/or physical abuse (CSA/CPA), ERP correlates of emotional word processing in 38 healthy participants and 40 adolescent participants with PTSD after experiencing CSA/CPA were studied. The experimental paradigm consisted of a passive reading task with neutral, positive (e.g., paradise), physically threatening (e.g., torment), and socially threatening (i.e., swearing, e.g., son of a bitch) words. A modulation of P3 amplitudes by emotional valence was found, with positive words inducing less elevated amplitudes over both groups. Interestingly, in later processing, the PTSD group showed augmented early late positive potential (LPP) amplitudes for socially threatening stimuli, while there were no modulations within the healthy control group. Also, region-specific emotional modulations for anterior and posterior electrode clusters were found. For the anterior LPP, highest activations have been found for positive words, while socially and physically threatening words led to strongest modulations in the posterior LPP cluster. There were no modulations by group or emotional valence at the P1 and EPN stage. The findings suggest an enhanced conscious processing of socially threatening words in adolescent patients with PTSD after CSA/CPA, pointing to the importance of a disjoined examination of threat words in emotional processing research.

Mineralocorticoid receptor haplotype moderates the effects of oral contraceptives and menstrual cycle on emotional information processing

RATIONALE

The processing of emotional information is affected by menstrual cycle phase and by the use of oral contraceptives (OCs). The stress hormone cortisol is known to affect emotional information processing via the limbic mineralocorticoid receptor (MR).

OBJECTIVES

We investigated in an exploratory study whether the MR-genotype moderates the effect of both OC-use and menstrual cycle phase on emotional cognition.

METHODS

Healthy premenopausal volunteers (n=93) of West-European descent completed a battery of emotional cognition tests. Forty-nine participants were OC users and 44 naturally cycling, 21 of whom were tested in the early follicular (EF) and 23 in the mid-luteal (ML) phase of the menstrual cycle.

RESULTS

In MR-haplotype 1/3 carriers, ML women gambled more than EF women when their risk to lose was relatively small. In MR-haplotype 2, ML women gambled more than EF women, regardless of their odds of winning. OC-users with MR-haplotype 1/3 recognised fewer facial expressions than ML women with MR-haplotype 1/3.

CONCLUSION

MR-haplotype 1/3 carriers may be more sensitive to the influence of their female hormonal status. MR-haplotype 2 carriers showed more risky decision-making. As this may reflect optimistic expectations, this finding may support previous observations in female carriers of MR-haplotype 2 in a naturalistic cohort study.

Mineralocorticoid receptor haplotype, oral contraceptives and emotional information processing

BACKGROUND

Oral contraceptives (OCs) affect mood in some women and may have more subtle effects on emotional information processing in many more users. Female carriers of mineralocorticoid receptor (MR) haplotype 2 have been shown to be more optimistic and less vulnerable to depression.

AIM

To investigate the effects of oral contraceptives on emotional information processing and a possible moderating effect of MR haplotype.

METHODS

Cross-sectional study in 85 healthy premenopausal women of West-European descent.

RESULTS

We found significant main effects of oral contraceptives on facial expression recognition, emotional memory and decision-making. Furthermore, carriers of MR haplotype 1 or 3 were sensitive to the impact of OCs on the recognition of sad and fearful faces and on emotional memory, whereas MR haplotype 2 carriers were not.

LIMITATIONS

Different compounds of OCs were included. No hormonal measures were taken. Most naturally cycling participants were assessed in the luteal phase of their menstrual cycle.

CONCLUSIONS

Carriers of MR haplotype 2 may be less sensitive to depressogenic side-effects of OCs.

Mindfulness training alters emotional memory recall compared to active controls: support for an emotional information processing model of mindfulness

Objectives: While mindfulness-based interventions have received widespread application in both clinical and non-clinical populations, the mechanism by which mindfulness meditation improves well-being remains elusive. One possibility is that mindfulness training alters the processing of emotional information, similar to prevailing cognitive models of depression and anxiety. The aim of this study was to investigate the effects of mindfulness training on emotional information processing (i.e., memory) biases in relation to both clinical symptomatology and well-being in comparison to active control conditions. Methods: Fifty-eight university students (28 female, age = 20.1 ± 2.7 years) participated in either a 12-week course containing a “meditation laboratory” or an active control course with similar content or experiential practice laboratory format (music). Participants completed an emotional word recall task and self-report questionnaires of well-being and clinical symptoms before and after the 12-week course. Results: Meditators showed greater increases in positive word recall compared to controls [F(1, 56) = 6.6, p = 0.02]. The meditation group increased significantly more on measures of well-being [F(1, 56) = 6.6, p = 0.01], with a marginal decrease in depression and anxiety [F(1, 56) = 3.0, p = 0.09] compared to controls. Increased positive word recall was associated with increased psychological well-being (r = 0.31, p = 0.02) and decreased clinical symptoms (r = −0.29, p = 0.03). Conclusion: Mindfulness training was associated with greater improvements in processing efficiency for positively valenced stimuli than active control conditions. This change in emotional information processing was associated with improvements in psychological well-being and less depression and anxiety. These data suggest that mindfulness training may improve well-being via changes in emotional information processing. Future research with a fully randomized design will be needed to clarify the possible influence of self-selection.