How long do mood induction procedure (MIP) primes really last? Implications for cognitive vulnerability research

Negative emotional cues improve free recall of positive and neutral words in unmedicated patients with major depressive disorder

Individuals with major depressive disorder (MDD) exhibit attentional biases toward negative, mood-congruent stimuli while filtering out positive and neutral stimuli, resulting in memory biases to negative content. While attentional and memory biases in MDD have been extensively studied, the underlying mechanisms of these biases remain unclear. The current study investigates a novel model proposing that exposure to negative emotional cues triggers a transient "attentional window" in individuals with MDD, leading to heightened and deeper cognitive processing of any subsequent information, irrespective of its content. Forty-two unmedicated patients with MDD and no comorbid disorder and 41 healthy controls, completed six blocks of the emotional memory task, in which they were asked to watch a short video (negative, neutral, or positive valence) followed by a memory test on a list of neutral or positive valance words. Results indicated that participants with MDD, but not healthy controls, had better recall performance after a negative video compared to after neutral or positive videos, and that this effect occurred for both neutral and positive word-lists. These findings provide evidence that participants with MDD engage in deeper information processing following exposure to negative emotional stimuli. Potential clinical implications are discussed.

Do you feel up when you go up? A pilot study of a virtual reality manic-like mood induction paradigm

OBJECTIVES

In order to understand the working mechanisms of mania, it is necessary to perform studies during the onset of manic (-like) mood states. However, clinical mania is difficult to examine experimentally. A viable method to study manic mood like states is mood induction, but mood induction tasks thus far show variable effectiveness.

METHODS

In this pilot study, a new paradigm to induce mood through virtual reality (VR) is examined. Both state characteristics, namely changes in emotion, and trait characteristics, such as high and low scores on the hypomanic personality scale (HPS), were measured in 65 students. These students participated in either a neutral VR mood induction or an activating VR mood induction in which excitement, goal directedness, and tension (being aspects of mania) were induced. All participants performed a risk-taking behavioural task, Balloon Analogue Risk Task (BART).

RESULTS

The experimental VR task induced excitement and tension. In participants with higher sensitivity to hypomanic personality (HPS), irritation increased in response to activation whereas it decreased in the low HPS group, and excitement increased more steeply in the low HPS group. There were no effects on the behavioural task.

CONCLUSIONS

The VR task is effective in inducing relevant state aspects of hypomania and is suitable as a paradigm for future experimental studies. Activation of dual affective states (excitement and tension) is an essential aspect in manic-like mood induction paradigms.

Exploring the 'mood congruency' hypothesis of attention allocation - An eye-tracking study

BACKGROUND

The 'mood-congruency' hypothesis of attention allocation postulates that individuals' current emotional states affect their attention allocation, such that mood-congruent stimuli take precedence over non-congruent ones. This hypothesis has been further suggested as an underlying mechanism of biased attention allocation in depression.

METHODS

The present research explored the mood-congruency hypothesis using a novel video-based mood elicitation procedure (MEP) and an established eye-tracking attention allocation assessment task, elaborating prior research in the field. Specifically, in Study 1 (n = 91), a video-based MEP was developed and rigorously validated. In study 2 (n = 60), participants' attention allocation to sad and happy face stimuli, each presented separately alongside neutral faces, was assessed before and after the video-based MEP, with happiness induced in one group (n = 30) while inducing sadness in the other (n = 30).

RESULTS

In Study 1, the MEP yielded the intended modification of participants' current mood states (eliciting either sadness or happiness). Study 2 showed that while the MEP modified mood in the intended direction in both groups, replicating the results of Study 1, corresponding changes in attention allocation did not ensue in either group. A Bayesian analysis of pre-to-post mood elicitation changes in attention allocation supported this null finding. Moreover, results revealed an attention bias to happy faces across both groups and assessment points, suggestive of a trait-like positive bias in attention allocation among non-selected participants.

CONCLUSION

Current results provide no evidence supporting the mood-congruency hypothesis, which suggests that (biased) attention allocation may be better conceptualized as a depressive trait, rather than a mood-congruent state.

Mood induction through imitation of full-body movements with different affective intentions

Theories of human emotion, including some emotion embodiment theories, suggest that our moods and affective states are reflected in the movements of our bodies. We used the reverse process for mood regulation; modulate body movements to regulate mood. Dancing is a type of full-body movement characterized by affective expressivity and, hence, offers the possibility to express different affective states through the same movement sequences. We tested whether the repeated imitation of a dancer performing two simple full-body dance movement sequences with different affective expressivity (happy or sad) could change mood states. Computer-based systems, using avatars as dance models to imitate, offer a series of advantages such as independence from physical contact and location. Therefore, we compared mood induction effects in two conditions: participants were asked to imitate dance movements from one of the two avatars showing: (a) videos of a human dancer model or (b) videos of a robot dancer model. The mood induction was successful for both happy and sad imitations, regardless of condition (human vs. robot avatar dance model). Moreover, the magnitude of happy mood induction and how much participants liked the task predicted work-related motivation after the mood induction. We conclude that mood regulation through dance movements is possible and beneficial in the work context.

Effects of positive and negative affect inductions on interpretive and response bias

Affective states and interpretations of ambiguous stimuli are inherently related constructs, although effects of induced affective states on interpretive and response biases have not been comprehensively explored. The present study examined the relationship between induced affective states and interpretive and response bias in a sample of 189 undergraduates. Participants completed an online study in which they were randomized into one of two mood induction conditions and subsequently completed an interpretive bias task. Results demonstrated significant condition differences in affect after the mood induction; the positive induction condition demonstrated significantly more positive mood and the negative condition demonstrated more negative mood. A significant difference between conditions emerged with respect to positive interpretive bias for non-social scenarios, with the positive mood induction condition demonstrating more positive interpretive bias to non-social situations than the negative induction condition (p = .04). The negative induction condition demonstrated significantly greater negative response bias for social scenarios (p = .03) and, unexpectedly, a significantly higher positive response bias for non-social scenarios (p = .05). Findings offer some support for the notion that inducing positive affect may promote more positive interpretations of ambiguous scenarios.

Duration of mood effects following a Japanese version of the mood induction task

Researchers have employed a variety of methodologies to induce positive and negative mood states in study participants to investigate the influence that mood has on psychological, physiological, and cognitive processes both in health and illness. Here, we investigated the effectiveness and the duration of mood effects following the mood induction task (MIT), a protocol that combines mood-inducing sentences, auditory stimuli, and autobiographical memory recall in a cohort of healthy Japanese adult individuals. In Study 1, we translated and augmented the mood-inducing sentences originally proposed by Velten in 1968 and verified that people perceived the translations as being largely congruent with the valence of the original sentences. In Study 2, we developed a Japanese version of the mood induction task (J-MIT) and examined its effectiveness using an online implementation. Results based on data collected immediately after induction showed that the J-MIT was able to modulate the mood in the intended direction. However, mood effects were not observed during the subsequent performance of a cognitive task, the Tower of London task, suggesting that the effects did not persist long enough. Overall, the current results show that mood induction procedures such as the J-MIT can alter the mood of study participants in the short term; however, at the same time, they highlight the need to further examine how mood effects evolve and persist through time to better understand how mood induction protocols can be used to study affective processes more effectively.

A causal link between mental imagery and affect-laden perception of climate change related risks

Previous studies have shed light on the importance of affect in risk perception and the role of mental imagery in generating affect. In the current study, we explore the causal relationship between mental imagery, affect, and risk perception by systematically varying the level of mental imagery in three levels (i.e., enhanced, spontaneous, or prevented). In light of the increasing environmental risk of adverse events caused by climate change, we operationalize risk as participants' perceived risk of climate change. One-thousand-fifty-five participants were recruited online and randomized to one of three levels of mental imagery. As predicted, we found a causal link between the level of mental imagery, affective experience, and perceived risk of climate change, in that enhanced mental imagery caused a larger decrease in positive affective valence and a larger increase in perceived risk of climate change. We argue that mental imagery enhances the negative affect associated with the risk event by creating a perceptual experience that mimics seeing the environmental risk events.

Reduced positive affect alters reward learning via reduced information encoding in the Reward Positivity

Reward Positivity (RewP) is a feedback-locked event-related potential component that is specifically elicited by rewarding feedback and scales with positive reward prediction error, a hallmark of reinforcement learning models. The RewP is also diminished in depression, suggesting that it may be a novel marker of anhedonia. Here, we examined if a sad mood induction offered an opportunity to causally induce a mood-related alteration of the RewP and reward-related learning. In Experiment 1 (N = 50 total), participants were randomly assigned to previously established sad or neutral mood induction procedures before a probabilistic selection task. This manipulation failed to induce changes in affect, suggesting that standard methods are inadequate. In Experiment 2 (N = 50 total), participants were randomly assigned to newly developed happy versus sad mood manipulations, which successfully induced large changes in affect. While the RewP was unaffected by mood induction, positive mood moderated the relationship between prediction error encoding in the RewP and reward learning, such that low positive mood and low prediction error encoding resulted in poorer reward learning. These findings provide a mechanistic example of how reduced positive affect moderates reward learning via poorer information encoding in the RewP.

Deontological and Utilitarian Responses to Sacrificial Dilemmas Predict Disapproval of Sin Stocks

Abstract. Investors sometimes invest in the so-called “sin” stocks that cause social harm as a by-product of doing business (e.g., tobacco companies). Three studies examined whether people who reject harm and maximize outcomes in sacrificial dilemmas approve less of investing in sin (but not conventional) stocks. We employed process dissociation to assess harm-rejection (deontological) and outcome-maximization (utilitarian) response tendencies independently. Study 1 ( N = 337) assessed moral approval of stocks: People scoring higher on either deontological or utilitarian response tendencies disapproved of investing in sin, but not conventional, stocks. Study 2 ( N = 402) replicated this effect for willingness to invest in companies abandoning (vs. retaining) socially responsible policies. Study 3 ( N = 558) confirmed earlier findings using more conservative measures. These findings clarify the psychology of morally questionable investment decisions.