Neural correlates of effective and ineffective mood induction

Abstract

Emotional reactivity and the ability to modulate an emotional state, which are important factors for psychological well-being, are often dysregulated in psychiatric disorders. Neural correlates of emotional states have mostly been studied at the group level, thereby neglecting individual differences in the intensity of emotional experience. This study investigates the relationship between brain activity and interindividual variation in subjective affect ratings. A standardized mood induction (MI) procedure, using positive facial expression and autobiographical memories, was applied to 54 healthy participants (28 female), who rated their subjective affective state before and after the MI. We performed a regression analysis with brain activation during MI and changes in subjective affect ratings. An increase in positive affective ratings correlated with activity in the amygdala, hippocampus and the fusiform gyrus (FFG), whereas reduced positive affect correlated with activity of the subgenual anterior cingulate cortex. Activations in the amygdala, hippocampus and FFG are possibly linked to strategies adopted by the participants to achieve mood changes. Subgenual cingulate cortex activation has been previously shown to relate to rumination. This finding is in line with previous observations of the subgenual cingulate's role in emotion regulation and its clinical relevance to therapy and prognosis of mood disorders.

Keywords: MACM; amygdale; fMRI; mood induction; subgenual ACC.

Fig. 1

In the upper half of the figure two sample images of the facial stimuli used for support in the mood induction are displayed. The lower half illustrates one mood induction run. Before the mood induction subjects had to rate their subjective affective state using PANAS and ESR (Emotional self rating, Schneider et al., 1994a), followed by mood induction blocks (60s) and baseline (mean: 54.4s).

Fig. 2

Displayed are PANAS difference score. The score reflects the change in subjective affect ratings. The positive and negative PANAS scores before and after the positive mood induction are substracted (and multiplied by −1 for ease of understanding). The blue bar displays change of positive PANAS and the red bar displays change in negative PANAS scores.

Fig. 3

Displayed are sections of significant clusters from the positive correlation of brain activation with subjective affect ratings on the left side, for the fusiform gyrus (a) and the amygdale and hippocampus cluster (b). Illustrated on the right side of the image is the correlation index of mean beta values from the respective cluster with subjective rating, the scatter plot of these values and colour coding of beta values in the image. All Correlations are significant (p < 0.01).

Fig. 4

Displayed are sections of significant clusters from the negative correlation of brain activation with subjective affect ratings on the left side for the subgenual anterior cortex. Illustrated on the right side of the image is the correlation index of mean beta values from the cluster with subjective rating (p<0.01), the scatter plot of these values and colour coding of beta values in the image.