Neurofunctional underpinnings of individual differences in visual episodic memory performance.

Episodic memory, the ability to consciously recollect information and its context, varies substantially among individuals. While prior fMRI studies have identified certain brain regions linked to successful memory encoding at a group level, their role in explaining individual memory differences remains largely unexplored. Here, we analyze fMRI data of 1,498 adults participating in a picture encoding task in a single MRI scanner. We find that individual differences in responsivity of the hippocampus, orbitofrontal cortex, and posterior cingulate cortex account for individual variability in episodic memory performance. While these regions also emerge in our group-level analysis, other regions, predominantly within the lateral occipital cortex, are related to successful memory encoding but not to individual memory variation. Furthermore, our network-based approach reveals a link between the responsivity of nine functional connectivity networks and individual memory variability. Our work provides insights into the neurofunctional correlates of individual differences in visual episodic memory performance.

Human cerebellum and corticocerebellar connections involved in emotional memory enhancement.

Emotional information is better remembered than neutral information. Extensive evidence indicates that the amygdala and its interactions with other cerebral regions play an important role in the memory-enhancing effect of emotional arousal. While the cerebellum has been found to be involved in fear conditioning, its role in emotional enhancement of episodic memory is less clear. To address this issue, we used a whole-brain functional MRI approach in 1,418 healthy participants. First, we identified clusters significantly activated during enhanced memory encoding of negative and positive emotional pictures. In addition to the well-known emotional memory-related cerebral regions, we identified a cluster in the cerebellum. We then used dynamic causal modeling and identified several cerebellar connections with increased connection strength corresponding to enhanced emotional memory, including one to a cluster covering the amygdala and hippocampus, and bidirectional connections with a cluster covering the anterior cingulate cortex. The present findings indicate that the cerebellum is an integral part of a network involved in emotional enhancement of episodic memory.

Sexual Dysfunctions in Patients Receiving Opioid Agonist Treatment and Heroin-Assisted Treatment Compared to Patients in Private Practice-Identifying Group Differences and Predictors.

Background and Aims: Sexual dysfunctions (SDs) show a marked impact on a person's general wellbeing. Several risk-factors like physical and mental illnesses as well as alcohol and tobacco use have to date been identified to contribute to the occurrence of SDs. The impact of opioid-agonist treatment (OAT) on SDs remains unclear, with some studies demonstrating an improvement after methadone maintenance treatment (MMT) initiation. However, no studies on the prevalence and predictors of SDs in heroin-assisted treatment (HAT) exist to date. Methods: A cross-sectional study was conducted with patients from a MMT center (n = 57) and a center specializing in HAT (n = 47). A control group of patients with mild transient illnesses (n = 67) was recruited from a general practitioner (GP). The International Index of Erectile Function, the Female Sexual Function Index, as well as measurements for psychological distress, depressive state, nicotine dependence, and high-risk alcohol use were employed. Patients also completed a self-designed questionnaire on help-seeking behavior regarding sexual health. Mann-Whitney-U tests and chi-square tests were performed for group comparisons and binary logistic regression models were calculated. Results: Twenty-five percent of the GP sample (n = 17), 70.2% (n = 40) of the MMT sample, and 57.4% (n = 27) of the HAT sample suffered from SDs at the time of study conduction. OAT patients differed significantly from GP patients in depressive state, high-risk alcohol use, nicotine dependence, and psychological distress. Age, depressive state, and opioid dependence predicted the occurrence of SDs in the total sample. No differences between OAT and GP patients were found regarding help-seeking behavior. Discussion: Age, depressive state, and opioid dependence predicted the occurrence of SDs in the total sample. It remains unclear whether SDs are caused by opioid intake itself or result from other substance-use related lifestyle factors, that were not controlled for in this study. A lack of help-seeking behavior was observed in our sample, underlining the importance of clinicians proactively inquiring about the sexual health of their patients. Conclusion: The high prevalence of SDs observed in MMT does not differ from the prevalence in HAT. Clinicians should actively inquire about their patients' sexual health in GP and OAT centers alike.

Resting-state functional connectivity remains unaffected by preceding exposure to aversive visual stimuli.

While much is known about immediate brain activity changes induced by the confrontation with emotional stimuli, the subsequent temporal unfolding of emotions has yet to be explored. To investigate whether exposure to emotionally aversive pictures affects subsequent resting-state networks differently from exposure to neutral pictures, a resting-state fMRI study implementing a two-group repeated-measures design in healthy young adults (N = 34) was conducted. We focused on investigating (i) patterns of amygdala whole-brain and hippocampus connectivity in both a seed-to-voxel and seed-to-seed approach, (ii) whole-brain resting-state networks with an independent component analysis coupled with dual regression, and (iii) the amygdala's fractional amplitude of low frequency fluctuations, all while EEG recording potential fluctuations in vigilance. In spite of the successful emotion induction, as demonstrated by stimuli rating and a memory-facilitating effect of negative emotionality, none of the resting-state measures was differentially affected by picture valence. In conclusion, resting-state networks connectivity as well as the amygdala's low frequency oscillations appear to be unaffected by preceding exposure to widely used emotionally aversive visual stimuli in healthy young adults.