Emotions and the Right Hemisphere: Editorial

Negative bias in early and late cognitive processing of coronary heart disease patients with depressive symptoms: an EPR study

BACKGROUND

The purpose of this research was to explore the underlying mechanisms of cognitive impairments in patients with coronary heart disease (CHD) who exhibit depressive symptoms. This was accomplished by recording Event-related potentials (ERPs) during the emotional Stroop task, with a specific focus on the temporal dynamics of attentional bias towards various emotional words.

METHODS

We selected 17 CHD patients with depressive symptoms and 23 CHD patients without depression using a convenience sampling method from the Affiliated Hospital of Weifang Medical University. Each participant completed an emotional Stroop color-word task, and ERPs were recorded during the task to examine cognitive processing.

RESULTS

CHD patients with depressive symptoms exhibited generally smaller amplitudes of N1, N2, P3 and longer latency of P3 compared to CHD patients without depression. Specifically, the N1 amplitude of negative words was smaller and the P3 amplitude of negative words was larger in the CHD with depressive group compared to the CHD group. Furthermore, within the group of CHD patients with depressive symptoms, negative words elicited a smaller N1 amplitude and larger P3 amplitude compared to positive and neutral words.

CONCLUSIONS

CHD patients with depressive symptoms demonstrate decreased attentional resources, leading to cognitive impairments. Notably, significant attentional bias occurs during both early and later stages of cognitive processing. This bias is primarily characterized by an enhanced automatic processing of negative information at the early stage and difficulty disengaging from such information at the later stage. These findings contribute to the existing literature on the cognitive neural mechanisms underlying depression in CHD patients.

Incidence of post-stroke depression symptoms and potential risk factors in adults with aphasia in a comprehensive stroke center

INTRODUCTION

Depression may be a frequent sequela after stroke, however, its incidence has rarely been reported. The likelihood of post-stroke depression (PSD) may relate to individual factors including the presence of aphasia, which also complicates PSD diagnosis. The current study's purpose was to investigate the incidence of PSD symptoms in adults with aphasia, compare it to the incidence of PSD symptoms in adults without aphasia, and to identify potential risk factors for developing PSD in adults with aphasia.

METHOD

Incidence proportions and relative risk were calculated using data compiled from 970 patient records at an urban tertiary care academic institution and comprehensive stroke center throughout the year of 2019. Focusing exclusively on adults with aphasia, the selected variables of age, gender, race, and aphasia severity were used to conduct logistic regression analyses to explore potential risk factors contributing to the development of PSD.

RESULTS

Adults with aphasia were 7.408 times more likely to exhibit PSD symptoms than adults without aphasia. Logistic regression controlling for the presence of aphasia showed a significant relationship between aphasia severity and post-stroke depression symptoms. Adults with aphasia were 2.06 times more likely to experience post-stroke depression symptoms with every 1-point increase in aphasia severity.

CONCLUSIONS

These findings align with earlier evidence identifying aphasia as a risk factor for experiencing PSD symptoms and also suggest aphasia severity is proportionate to the risk. This highlights the need for early identification of PSD symptoms in persons with aphasia in order to provide timely interventions.

Ewww-Investigating the neural basis of disgust in response to naturalistic and pictorial nauseating stimuli

Emotion induction in psychological and neuroscientific research has been mostly done by presenting participants with picture or film material. However, it is debatable whether this passive approach to emotion induction results in an affective state comparable to real-life emotions, and if the neural correlates of emotion processing are ecologically valid. To investigate the appropriateness of pictures for the induction of emotions, we presented 56 participants in a within-subjects design with naturalistic disgusting and neutral stimuli as well as with pictures of said stimulus material while recording continuous EEG data. We calculated asymmetry indices (AIs) for alpha power as an index of emotion processing and emotion regulation at the F3/4, F5/6, F7/8, and O1/2 electrode pairs. Participants reported higher disgust ratings for disgusting naturalistic compared to disgusting pictorial stimuli. Investigating changes in the EEG signal in participants with a pronounced disgust response (n = 38), we found smaller AIs for naturalistic stimuli compared to pictures. Moreover, in this disgusted sub-sample, there were smaller AIs in response to naturalistic disgusting stimuli compared to pictorial disgusting and neutral stimuli at the O1/2 electrode pair indicating stronger activation of the right relative to the left hemisphere by naturalistic stimuli. As the right hemisphere has been shown to display dominance in processing negative and withdrawal-associated emotions, this might indicate that naturalistic stimuli are more appropriate for the induction of emotions than picture stimuli. To improve the validity of results from emotion induction, future research should incorporate stimulus material that is as naturalistic as possible.

Investigating form and content of emotional and non-emotional laughing

As cold actions (i.e. actions devoid of an emotional content), also emotions are expressed with different vitality forms. For example, when an individual experiences a positive emotion, such as laughing as expression of happiness, this emotion can be conveyed to others by different intensities of face expressions and body postures. In the present study, we investigated whether the observation of emotions, expressed with different vitality forms, activates the same neural structures as those involved in cold action vitality forms processing. To this purpose, we carried out a functional magnetic resonance imaging study in which participants were tested in 2 conditions: emotional and non-emotional laughing both conveying different vitality forms. There are 3 main results. First, the observation of emotional and non-emotional laughing conveying different vitality forms activates the insula. Second, the observation of emotional laughing activates a series of subcortical structures known to be related to emotions. Furthermore, a region of interest analysis carried out in these structures reveals a significant modulation of the blood-oxygen-leveldependent (BOLD) signal during the processing of different vitality forms exclusively in the right amygdala, right anterior thalamus/hypothalamus, and periaqueductal gray. Third, in a subsequent electromyography study, we found a correlation between the zygomatic muscles activity and BOLD signal in the right amygdala only.