Neural correlates of empathy for babies in postpartum women: A longitudinal study.

This study investigated the empathic response of postpartum women to babies in pain and the underlying neural mechanism. Postpartum women responded with more empathy and speed to babies over other stimuli compared to controls. Brain scans taken 3 months after birth showed more elevated activation in the Middle cingulate cortex/middle frontal gyrus (MCC/MFG) than the controls regardless of the task condition. When compared to the adult and neutral conditions, the posterior cingulate cortex (PCC) region was consistently more activated when postpartum women saw babies than controls. In addition, higher activation levels in the PCC region for the baby condition significantly correlated with faster and more empathic responses to babies. Considering that PCC is a core region for the theory of mind or mentalizing which requires cognitive reasoning to understand others, these results suggest that PCC might be a pivotal neural locus facilitating cognitive efforts to empathize with babies during the postpartum period. In a follow-up experiment at 12 months after birth, we were still able to observe higher activity in the MCC/MFG of postpartum women. However, previously observed PCC activation patterns disappeared 12 months after birth, despite the women's response patterns to babies still being maintained. These results suggest that the mentalizing process activated to empathize with babies in the early postpartum period becomes less cognitively demanding over time.

Altered task-dependent functional connectivity patterns during subjective recollection experiences of episodic retrieval in postpartum women.

Numerous studies have suggested that postpartum women show a decline in cognitive abilities. However, to date, no study has investigated the presence of qualitative alterations in recognition memory processes in postpartum women that may lead to a decline in cognitive ability. To address this issue, we employed the Remember/Know procedure and functional magnetic resonance imaging (fMRI). Behavioral results demonstrated that compared with the matched control (CTRL) group, the postpartum (PP) group endorsed "Remember" less and "Know" more to old items. A univariate analysis of fMRI data indicated lower neural activity of the subjective recollection network in the PP group than in the CTRL group. We also performed a large-scale functional connectivity multivariate pattern analysis (fcMVPA) using task-dependent time-series to detect differences in functional connectivity patterns and neural interactivity between the PP and CTRL groups. The fcMVPA results revealed that the PP group exhibited altered functional connectivity patterns from which machine learning algorithms could discriminate group membership with 94% accuracy. Collectively, these findings demonstrated that altered subjective recollection processes in the PP group during episodic memory decisions are associated with diminished neural activity and abnormal interactivity across the subjective recollection network. We believe that this is one of the first studies demonstrating qualitative alterations in recognition memory processes in postpartum women.

Prefrontal cortical activation in Internet Gaming Disorder Scale high scorers during actual real-time internet gaming: A preliminary study using fNIRS.

Background: Observation of real-time neural characteristics during gameplay would provide distinct evidence for discriminating the currently controversial diagnosis of internet gaming disorder (IGD), and elucidate neural mechanisms that may be involved in addiction. We aimed to provide preliminary findings on possible neural features of IGD during real-time internet gaming using functional near-infrared spectroscopy (fNIRS). Methods: Prefrontal cortical activations accompanying positive and negative in-game events were investigated. Positive events: (1) participant's champion slays or assists in slaying an opponent without being slain. (2) the opposing team's nexus is destroyed. Negative events: (1) participant's champion is slain without slaying or assisting in slaying any opponent. (2) the team's nexus is destroyed. Collected data were compared between the IGD group and control group, each with 15 participants. Results: The IGD group scored significantly higher than the CTRL group on the craving scale. Following positive events, the IGD group displayed significantly stronger activation in the DLPFC. Following negative events, the IGD group displayed significantly weaker activation in the lateral OFC. Discussion and Conclusions: Individuals scoring high on the IGD scale may crave for more internet gaming after encountering desired events during the game. Such observations are supported by the correlation between the craving scale and DLPFC activation. The IGD group may also show diminished punishment sensitivity to negative in-game experiences rendering them to continue playing the game. The present study provides preliminary evidence that IGD may demonstrate neural characteristics observed in other addictive disorders and suggests the use of fNIRS in behavioral addiction studies.

Altered neural substrates within cognitive networks of postpartum women during working memory process and resting-state.

Postpartum working memory decline has been investigated mostly with neuropsychological tests, but neural evidence is almost unknown. Here we investigated task-related neural alterations during working memory task (n-back) and intrinsic alterations during resting-state (rs) in postpartum women using functional MRI (fMRI). Behaviorally, postpartum women showed comparable working memory performances to the controls although there was a tendency of prolonged response time. fMRI analysis results showed hyper-activation in regions belong to the task positive network (TPN) during the task and hypo-rsfMRI values in the default mode network (DMN) regions during rest in postpartum women. Based on these results, we performed network connectivity analysis using nodes of the TPN and DMN. As a result, the DMN showed a tendency of decreased connectivity in postpartum women during the working memory process compared to the controls. Our results suggest that postpartum women might have functional alterations in the DMN, and that hyper-activation in the TPN during a task might be a compensatory mechanism to maintain working memory performance in postpartum women.

Data on subjective recollection effects reflected in large-scale functional connectivity patterns in postpartum women.

Functional neuroimaging data was collected while postpartum women and age-matched control women performed the Remember/Know judgment task in the functional magnetic resonance imaging scanner. This data provides information about functional connectivity patterns across the subjective recollection networks that were informative in differentiating the postpartum women from control women. Classification performances based on machine learning algorithms and descriptions of functional connectivity patterns that derived the peak classification accuracy are reported in this article. All other results from our study have been reported in Nah et al. (2018) [1].

Author Correction: Disturbed retrieval network and prospective memory decline in postpartum women.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

Disturbed retrieval network and prospective memory decline in postpartum women.

Prospective memory (PM) refers to the ability to remember to execute an intended action in the future. For successful PM performance, both top-down strategic monitoring and bottom-up spontaneous retrieval processes need to be appropriately recruited. We assessed PM performance and used fMRI to discover relevant neural correlates and possible predictors for PM performance in 25 postpartum and 26 nulliparous age- and education-matched women. Postpartum women showed decreased PM performance, a higher number of nocturnal awakenings, and lower estradiol level. The postpartum women had decreased functional connectivity (FC) in the right hippocampus and ventral frontoparietal networks (FPN) during retrieval-dominant PM trials relative to maintenance-dominant ongoing trials in the PM block. On multivariate analyses, decreased FC between the right hippocampus and ventral FPN and a higher number of nocturnal awakenings were independent predictors for poor PM performance after adjusting for age, education, estradiol level, and depressive symptoms. On mediation analyses, the estradiol level was found to have an indirect effect on PM accuracy via altered FC as a mediator. This suggests that decreased FC within the spontaneous retrieval-related regions including the right hippocampus and ventral FPN, disrupted sleep rhythms, and decreased estradiol level may contribute to poor PM performance in postpartum women.