Temperament Clusters in Patients With Panic Disorder in Relation to Character Maturity.

OBJECTIVE: This study explored whether temperament profiles are associated with psychological functioning and whether character maturity affects this association in patients with panic disorders (PD). METHODS: A total of 270 patients with PD were enrolled in this study. Measurements included the Temperament and Character Inventory-revised-short (TCI-RS), a self-report version of the Panic Disorder Severity Scale (PDSS-SR), Beck Depression Inventory-II (BDI-II), and Spielberger State-Trait Anxiety Inventory (STAI). Cluster analysis was used to define the patients' temperament profiles, and the differences in discrete variables among temperament clusters were calculated using a one-way analysis of variance. An analysis of covariance was conducted to control for the impact of character maturity on psychological functioning among clusters. RESULTS: We identified four temperament clusters of patients with PD. Significant differences in the PDSS-SR, BDI-II, STAI-state, and STAI-trait scores among the four clusters were detected [F(3, 262)=9.16, p<0.001; F(3, 266)=33.78, p<0.001; F(3, 266)=19.12, p<0.001; F(3, 266)=39.46, p<0.001]. However, after controlling for the effect of character maturity, the effect of cluster type was either eliminated or reduced ([STAI-state] cluster type: F(3, 262)=0.94, p>0.05; SD+CO: F(1, 262)=65.95, p<0.001, ηp2 =0.20). CONCLUSION: This study enabled a more comprehensive and integrated understanding of patients by exploring the configuration of all temperament dimensions together rather than each temperament separately. Furthermore, we revealed that depending on the degree of character maturity, the psychological functioning might differ even within the same temperament cluster. These results imply that character maturity can complement inherently vulnerable temperament expression.

Contribution of dysfunctional sleep-related cognitions on insomnia severity: a network perspective.

STUDY OBJECTIVES: Various models of insomnia stress the role of cognitive components, such as dysfunctional sleep-related beliefs, in maintenance and exacerbation of insomnia. This study aimed to use network analysis to identify the particular beliefs that are central and have strong associations with insomnia severity. In addition, we aimed to use a relative importance network to map out predictive pathways between types of dysfunctional beliefs and insomnia severity. METHODS: This study was a retrospective study, with data collected from 219 patients with insomnia. Patients' responses to the Dysfunctional Beliefs about Sleep Scale-16 (DBAS-16) and Insomnia Severity Index (ISI) were collected. All network analyses were performed using R Studio to produce 3 networks: (1) DBAS-16 network, (2) DBAS-16 and ISI network, and (3) relative importance network containing DBAS-16 subscales and ISI. RESULTS: Beliefs reflecting overestimation of negative consequences of sleep (eg, "insomnia is ruining life"), loss of ability (eg, "worry about losing abilities to sleep"), and unpredictability (eg, "can't predict sleep quality") were identified as most central and strongly associated with insomnia severity. Worry/helplessness about insomnia had the largest predictive value on insomnia severity, and also acted as a mediator between other subscales and insomnia severity. CONCLUSIONS: The results of our study suggest that overestimation of negative consequences, loss of ability, and unpredictability are key beliefs that exacerbate and maintain insomnia, thus supporting existing cognitive models of insomnia. CITATION: Cha EJ, Hong S, Kim S, Chung S, Jeon HJ. Contribution of dysfunctional sleep-related cognitions on insomnia severity: a network perspective. J Clin Sleep Med. 2024;20(5):743-751.

Prior expectation enhances sensorimotor behavior by modulating population tuning and subspace activity in sensory cortex.

Prior knowledge facilitates our perception and goal-directed behaviors, particularly when sensory input is lacking or noisy. However, the neural mechanisms underlying the improvement in sensorimotor behavior by prior expectations remain unknown. In this study, we examine the neural activity in the middle temporal (MT) area of visual cortex while monkeys perform a smooth pursuit eye movement task with prior expectation of the visual target's motion direction. Prior expectations discriminately reduce the MT neural responses depending on their preferred directions, when the sensory evidence is weak. This response reduction effectively sharpens neural population direction tuning. Simulations with a realistic MT population demonstrate that sharpening the tuning can explain the biases and variabilities in smooth pursuit, suggesting that neural computations in the sensory area alone can underpin the integration of prior knowledge and sensory evidence. State-space analysis further supports this by revealing neural signals of prior expectations in the MT population activity that correlate with behavioral changes.

Multivariate EEG activity reflects the Bayesian integration and the integrated Galilean relative velocity of sensory motion during sensorimotor behavior.

Humans integrate multiple sources of information for action-taking, using the reliability of each source to allocate weight to the data. This reliability-weighted information integration is a crucial property of Bayesian inference. In this study, participants were asked to perform a smooth pursuit eye movement task in which we independently manipulated the reliability of pursuit target motion and the direction-of-motion cue. Through an analysis of pursuit initiation and multivariate electroencephalography activity, we found neural and behavioral evidence of Bayesian information integration: more attraction toward the cue direction was generated when the target motion was weak and unreliable. Furthermore, using mathematical modeling, we found that the neural signature of Bayesian information integration had extra-retinal origins, although most of the multivariate electroencephalography activity patterns during pursuit were best correlated with the retinal velocity errors accumulated over time. Our results demonstrated neural implementation of Bayesian inference in human oculomotor behavior.

The Mediating Effect of Insomnia on the Relationship between Panic Symptoms and Depression in Patients with Panic Disorder.

BACKGROUND: This study aimed to determine if sleep disturbances may mediate the relationship between panic symptoms and depression in patients with panic disorder (PD). METHODS: Electronic medical records were retrospectively reviewed for 110 consecutive patients with diagnosed PD in an outpatient clinic between October 2018 and December 2019. Measurements include the PD Severity Scale, Beck Depression Inventory-II (BDI-II) and Insomnia Severity Index (ISI). Statistical analyses were performed to assess any potential relationship between PD, insomnia and depression. RESULTS: Of the PD patients, 88 (80%) and 89 (80.9%) had comorbid depression (BDI-II ≥ 14) and insomnia (Korean version of the ISI ≥ 8), respectively. In a mediation model using insomnia as the mediating variable, the total effect of panic symptom severity on depression was significant (t = 7.23, P < 0.001). There were significant effects of panic symptoms on insomnia (t = 4.62, P < 0.001) and of insomnia on depression (t = 6.69, P < 0.001). The main effect of panic symptom severity on depression was also significant, after controlling for the effect of insomnia (t = 5.10, P < 0.001), suggesting partial mediation. CONCLUSION: Both depressive symptoms and insomnia are common in patients with PD and depression was partially mediated by insomnia in these patients. These results suggest that an intervention for insomnia in patients with PD might help prevent the development of depression.

Motion direction representation in multivariate electroencephalography activity for smooth pursuit eye movements.

Visually-guided smooth pursuit eye movements are composed of initial open-loop and later steady-state periods. Feedforward sensory information dominates the motor behavior during the open-loop pursuit, and a more complex feedback loop regulates the steady-state pursuit. To understand the neural representations of motion direction during open-loop and steady-state smooth pursuits, we recorded electroencephalography (EEG) responses from human observers while they tracked random-dot kinematograms as pursuit targets. We estimated population direction tuning curves from multivariate EEG activity using an inverted encoding model. We found significant direction tuning curves as early as about 60 ms from stimulus onset. Direction tuning responses were generalized to later times during the open-loop smooth pursuit, but they became more dynamic during the later steady-state pursuit. The encoding quality of retinal motion direction information estimated from the early direction tuning curves was predictive of trial-by-trial variation in initial pursuit directions. These results suggest that the movement directions of open-loop smooth pursuit are guided by the representation of the retinal motion present in the multivariate EEG activity.

Brain structural changes after multi-strategic metamemory training in older adults with subjective memory complaints: A randomized controlled trial.

BACKGROUND: Metamemory is the process of monitoring and controlling one's memory. Improving metamemory may reduce the memory problem in old age. We hypothesized that metamemory training (MMT) would improve cognition in older adults with subjective memory complaints and change the brain region related to metacognition. METHOD: We recruited and randomized older adults to the multi-strategic memory training of 10 weekly 90-min sessions, based on the metamemory concept or usual care. Cognitive tests including the Elderly Verbal Learning Test, Simple Rey Figure Test, Digit Span, Spatial Span, Categorical Fluency, and the Boston Naming Test were done in 201 participants, together with magnetic resonance imaging (MRI) in 49 participants before and after training. RESULTS: A total of 112 in the training group and 89 in the control group participated. The training group had a significant increase in long-term delayed free recall, categorical fluency, and the Boston Naming test. In MRI, the mean diffusivity of the bundles of axon tracts passing from the frontal lobe to the posterior end of the lateral sulcus decreased in the training group. CONCLUSION: These results indicate that the MMT program has a positive impact on enhancing older people' cognitive performance. Improved white matter integrity in the anterior and posterior cerebrum and increased cortical thickness of prefrontal regions, which related to metacognition, possibly suggest that the effects of the MMT would be induced via the enhancement of cognitive control.

Effect of Prior Direction Expectation on the Accuracy and Precision of Smooth Pursuit Eye Movements.

The integration of sensory with top-down cognitive signals for generating appropriate sensory-motor behaviors is an important issue in understanding the brain's information processes. Recent studies have demonstrated that the interplay between sensory and high-level signals in oculomotor behavior could be explained by Bayesian inference. Specifically, prior knowledge for motion speed introduces a bias in the speed of smooth pursuit eye movements. The other important prediction of Bayesian inference is variability reduction by prior expectation; however, there is insufficient evidence in oculomotor behaviors to support this prediction. In the present study, we trained monkeys to switch the prior expectation about motion direction and independently controlled the strength of the motion stimulus. Under identical sensory stimulus conditions, we tested if prior knowledge about the motion direction reduced the variability of open-loop smooth pursuit eye movements. We observed a significant reduction when the prior expectation was strong; this was consistent with the prediction of Bayesian inference. Taking advantage of the open-loop smooth pursuit, we investigated the temporal dynamics of the effect of the prior to the pursuit direction bias and variability. This analysis demonstrated that the strength of the sensory evidence depended not only on the strength of the sensory stimulus but also on the time required for the pursuit system to form a neural sensory representation. Finally, we demonstrated that the variability and directional bias change by prior knowledge were quantitatively explained by the Bayesian observer model.

Is Internet overuse associated with impaired empathic ability in Korean college students?

The purpose of the present study was to determine whether Internet overuse was associated with empathic ability in college students.A total 261 participants (145 males and 116 females; mean age of 21.93 years) completed Empathy Quotient (EQ), Young's Internet Addiction Test (IAT), and questionnaires about demographic data and internet using patterns.Of these 261 subjects, 85 (32.5%) were categorized as over-users. There was no significant difference in EQ total score between the over-user group and the average user group. The over-user group had lower scores of Social Skills than the average user group in subscale profiles. The over-user group stayed longer in cyberspace than the average user group. EQ score was found to have positive correlation with time spent in Internet use and the number of close friends.Results of the present study suggest that conventional Internet use is positively associated with empathic ability in interpersonal relationships. Therefore, such positive association between Internet use and empathic ability should be considered when evaluating possible problematic internet use.

A Systematic Analysis of Drosophila Regulatory Peptide Expression in Enteroendocrine Cells.

The digestive system is gaining interest as a major regulator of various functions including immune defense, nutrient accumulation, and regulation of feeding behavior, aside from its conventional function as a digestive organ. The Drosophila midgut epithelium is completely renewed every 1-2 weeks due to differentiation of pluripotent intestinal stem cells in the midgut. Intestinal stem cells constantly divide and differentiate into enterocytes that secrete digestive enzymes and absorb nutrients, or enteroendocrine cells that secrete regulatory peptides. Regulatory peptides have important roles in development and metabolism, but study has mainly focused on expression and functions in the nervous system, and not much is known about the roles in endocrine functions of enteroendocrine cells. We systemically examined the expression of 45 regulatory peptide genes in the Drosophila midgut, and verified that at least 10 genes are expressed in the midgut enteroendocrine cells through RT-PCR, in situ hybridization, antisera, and 25 regulatory peptide-GAL transgenes. The Drosophila midgut is highly compartmentalized, and individual peptides in enteroendocrine cells were observed to express in specific regions of the midgut. We also confirmed that some peptides expressed in the same region of the midgut are expressed in mutually exclusive enteroendocrine cells. These results indicate that the midgut enteroendocrine cells are functionally differentiated into different subgroups. Through this study, we have established a basis to study regulatory peptide functions in enteroendocrine cells as well as the complex organization of enteroendocrine cells in the Drosophila midgut.

Path analysis of suicide ideation in older people.

BACKGROUND: Suicide among older people is one of the most rapidly emerging healthcare issues. The objective of this study was to identify the factors associated with suicide ideation in the aged population in South Korea. METHODS: The study recruited 684 subjects older than 65 years old (males = 147, females = 537, mean age = 78.20±7.02 years), and trained interviewers performed the interviews. The study was performed as part of a community mental health suicide prevention program. The subjects' socio-demographic data, physical health, alcohol problems, social relationships, psychological well-being, and depression severity were all considered. The Korean version of the Beck Scale for Suicide Ideation (K-BSI) was used to evaluate the intensity of suicide ideation. Correlation and hierarchical multiple regression analyses were performed to identify the factors associated with the K-BSI. The study results were tested using a path analysis. RESULTS: Depression severity was positively correlated with suicide ideation, and economic status, psychological well-being, and social relationships were negatively correlated with suicide ideation. Depression severity had the largest direct impact, and economic status and social relationships had indirect impacts on suicide ideation. Psychological well-being exerted both direct and indirect influences. CONCLUSION: Depression severity was the most important predictor of suicide ideation among older people. Other direct and indirect factors played secondary roles. Effective suicide prevention strategies should focus on early detection and active intervention for depression. Socio-economic programs may also indirectly reduce suicide ideation among the aged population.

Normative study of the category fluency test (CFT) from nationwide data on community-dwelling elderly in Korea.

OBJECTIVES: We determined the influence of demographic characteristics on the categorical verbal fluency and to provided its' normative data for the community-dwelling elderly with diverse educational attainment. METHODS: We administered the CFT using the animal category to 3025 (1420 men and 1605 women) non-demented community-dwelling Koreans aged 60-96 years who had educational levels ranging from 0 to 22 years. RESULTS: Age and education were associated significantly with performance of CFT, with education showing the stronger association. Education accounted for 14.0% of CFT score variance and age accounted for 3.2%. However, gender did not influence performance of the test. We present normative data for CFT stratified by age (60-64, 65-69, 70-74, 75-79, 80-84, and ≥85 years) and education (0, 1-3, 4-6, 7-9, 10-12, and ≥13 years). CONCLUSIONS: The CFT norms should provide clinically useful data for evaluating elderly people and help improve the interpretation of verbal fluency tasks and allow for greater diagnostic accuracy for cognitive disorders such as Alzheimer's disease (AD).

Multistrategic memory training with the metamemory concept in healthy older adults.

OBJECTIVE: According to the increase of older people, the need for effective methods to maintain or improve cognitive functions in the elderly has increased. These cognitive enhancing methods may contribute to the prevention of elderly cognitive decline by aging and dementing illness as well. This study aimed to examine the effectiveness of multistrategic memory training with the metamemory concept on cognitive functions in the normal health elderly in Korea. METHODS: The program used in this study was developed by psychiatrists and psychologists in accordance with Korean situations. We applied the training program to the community-dwelling elderly with subjective memory complaints. Twenty participants were randomly received the intervention with 20 non-treatment controls. This program consisted of 10 sessions and was administered once a week. We examined the effects of this memory training for verbal memory, visuospatial memory, working memory, and verbal fluency ability by repeated ANOVA. RESULTS: There were significant improvements in Word List Short-term Delayed Free and Cued Recall, Word list Long-term Delayed Free and Cued Recall and visuospatial recognition memory. Performance improvements in visuospatial span forwards and the Categorical Fluency Test were also significant. These improvements were still significant after adjusting for depression improvement exact categorical fluency. CONCLUSION: This study shows that multistrategic memory training with the metamemory concept may improve memory ability and other cognitive functions which are not trained and that these improvements may be achieved by pure cognitive training effects.