High-difficulty Group Research Articles

Electroencephalography Neurofeedback Training with Focus on the State of Attention: An Investigation Using Source Localization and Effective Connectivity.

Identifying brain activity and flow direction can help in monitoring the effectiveness of neurofeedback tasks that aim to treat cognitive deficits. The goal of this study was to compare the neuronal electrical activity of the cortex between individuals from two groups-low and high difficulty-based on a spatial analysis of electroencephalography (EEG) acquired through neurofeedback sessions. These sessions require the subjects to maintain their state of attention when executing a task. EEG data were collected during three neurofeedback sessions for each person, including theta and beta frequencies, followed by a comprehensive preprocessing. The inverse solution based on cortical current density was applied to identify brain regions related to the state of attention. Thereafter, effective connectivity between those regions was estimated using the Directed Transfer Function. The average cortical current density of the high-difficulty group demonstrated that the medial prefrontal, dorsolateral prefrontal, and temporal regions are related to the attentional state. In contrast, the low-difficulty group presented higher current density values in the central regions. Furthermore, for both theta and beta frequencies, for the high-difficulty group, flows left and entered several regions, unlike the low-difficulty group, which presented flows leaving a single region. In this study, we identified which brain regions are related to the state of attention in individuals who perform more demanding tasks (high-difficulty group).

A novel scoring system based on magnetic resonance imaging for the prediction of the difficulty of ultrasound-guided high-intensity focused ultrasound ablation for uterine fibroids

Objective To develop a novel scoring system based on magnetic resonance imaging (MRI) for predicting the difficulty of ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation for uterine fibroids. Materials and methods A total of 637 patients with uterine fibroids were enrolled. Sonication time, non-perfused volume ratio (NPVR), and ultrasound energy delivered for ablating 1 mm3 of fibroid tissue volume (E/V) were each classified as three levels and assigned scores from 0 to 2, respectively. Treatment difficulty level was then assessed by adding up the scores of sonication time, NPVR and E/V for each patient. The patients with score lower than 3 were categorized into low difficulty group, with score equal to or greater than 3 were categorized into high difficulty group. The potential predictors for treatment difficulty were compared between the two groups. Multifactorial logistic regression analysis model was created by analyzing the variables. The difficulty score system was developed using the beta coefficients of the logistic model. Results Signal intensity on T2WI, fibroid location index, largest diameter of fibroids, abdominal wall thickness, homogeneity of the signal of fibroids, and uterine position were independent influencing factors for the difficulty of USgHIFU for uterine fibroids. A prediction equation was obtained: difficulty score = 17 × uterine position (anteverted =0, retroverted =1)+71 × signal intensity (hypointense = 0, isointense/hyperintense = 1) +8 × enhancement (homogenous = 0, heterogeneous = 1)+25×(largest diameter of fibroids-20) +35 × (fibroid location index −0.2) +1×(abdominal wall thickness −5). Conclusions This scoring system established based on MRI findings can be used to reliably predict the difficulty level of USgHIFU treatment of uterine fibroids.

More challenging or more achievable? The impacts of difficulty and dominant goal orientation in leaderboards within educational gamification

AbstractBackgroundAs one of the gamification elements, leaderboard, especially absolute leaderboard, is widely used in educational gamification systems. However, empirical studies on the optimal use condition of the leaderboard and underlying influence mechanisms are deficient.ObjectivesThis study explored which difficulty was more conducive to learning performance in leaderboard context, and when and how it played a role.MethodsTo address these questions, this study conducted a 2 (dominant goal orientation: learning/performance) × 2 (difficulty: high/low) between‐subjects design. Seventy‐eight dominant learning‐oriented and 78 dominant performance‐oriented participants were recruited and randomly assigned to the high or low difficulty group respectively.Results and ConclusionsParticipants in the low difficulty group experienced more positive emotions, less negative emotions, and higher learning motivation than those in the high difficulty group, but the effect of difficulty on performance was not significant. Moreover, goal orientation did not moderate the effects of difficulty, dominant learning‐oriented and performance‐oriented learners were equally affected by difficulty. Further mediating analysis showed that negative emotions and learning motivation rather than positive emotions mediated the relationship between difficulty and learning performance.ImplicationsThese results confirmed the positive effect of low difficulty in leaderboard context, as well as the mediating roles of emotions and motivation involved in the relationship between difficulty and learning performance. These findings enlighten us that it is necessary to equip leaderboards in educational gamification with achievable difficulty.

Clinical application value of difficulty score systems before laparoscopic liver resection

Objective To investigate the accuracy of three laparoscopic liver resection (LLR) difficulty score systems (DSSs) in evaluating surgical difficulty and predicting short-term postoperative outcome. Methods The retrospective cohort study was conducted for 142 patients who underwent LLR in The First Hospital of Lanzhou University from June 2015 to May 2020, and their preoperative, intraoperative, and postoperative clinical data were collected. According to preoperative clinical data, DSS-B score, Hasegawa score, and Halls score were used to determine the difficulty score of surgery for each patient, and then the patients were divided into low, medium, and high difficulty groups. Intraoperative data were compared between the three groups to verify the accuracy of the three DSSs, and postoperative clinical data were used to evaluate the ability of DSSs to predict short-term postoperative outcome. An analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups; the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple or two groups. The chi-square test or the Fisher's exact test was used for comparison of categorical data between groups, and the Bonferroni method was used for correction of P values between two groups. The receiver operating characteristic (ROC) curve was plotted and the area under the ROC curve (AUC) was calculated to evaluate the efficiency of each DSS in predicting postoperative complications. Results Among the 142 patients, there were 37 patients in the low difficulty group, 56 in the medium difficulty group, and 49 in the high difficulty group based on DSS-B score; there were 70 patients in the low difficulty group, 47 in the medium difficulty group, and 25 in the high difficulty group based on Hasegawa score; there were 46 patients in the low difficulty group, 62 in the medium difficulty group, and 34 in the high difficulty group based on Halls score. For the low, medium, and high difficulty groups based on DSS-B score, Hasegawa score, or Halls score, time of operation, intraoperative blood loss, and rate of hepatic portal occlusion increased with the increase in difficulty score (all P Conclusion DSS-B score and Hasegawa score can better assess the difficulty of LLR, and Hasegawa score has an advantage in predicting short-term postoperative outcome.

Internalizing and externalizing symptoms in Spanish children aged 6-8: Results of a latent profile analysis

BackgroundInternalizing and externalizing problems are widely addressed in research. However, most studies use variable-centred approaches and ignore the possible co-occurrence of both types of symptoms. This study aimed to identify homogeneous groups of children with similar psychological difficulties and strengths, using latent profile analysis as a person-centred approach. MethodsThe parents of 107 Spanish children aged 6 to 8 years completed the Strengths and Difficulties Questionnaire (SDQ). ResultsThe results revealed the existence of four latent groups. The children who belonged to the high difficulties group showed the most severe symptoms in emotional problems, peer problems and hyperactivity. The children classified in the externalizing group showed high levels of hyperactivity, behavioral problems, and emotional problems. On another hand, the internalizing profile grouped children with emotional and peer problems. Finally, the well-adjusted group showed an adequate psychological adjustment in all evaluated variables. High difficulties were associated with lower educational attainment of their parents. LimitationsData were reported from a single source of information, father or mother. Also, the socio-demographic variables that were related to each one of the four profiles only considered the age and educational level of the main informant. ConclusionsThese data suggest that co-occurrence of symptoms is very high in young Spanish children. It is essential to carry out clinical assessments that include both types of symptoms. Considering externalization and internalization as independent and exclusive phenomena can compromise the effectiveness of psychological treatments and preventive programs.

A novel difficulty grading system for laparoscopic living donor nephrectomy

BackgroundSeveral difficulty grading systems have been developed as a useful tool for selecting patients and training surgeons in laparoscopic procedures. However, there is little information on predicting the difficulty of laparoscopic donor nephrectomy (LDN). The aim of this study was to develop a grading system to predict the difficulty of LDN.MethodsData of 1741 living donors, who underwent pure or hand-assisted LDN between 1994 and 2018 were analyzed. Multivariable analyses were performed to identify factors associated with prolonged operative time, defined as a difficulty index with 0 to 8. The difficulty of LDN was classified into three levels based on the difficulty index.ResultsMultivariable analyses identified that male (odds ratio [OR] 1.69, 95% CI 1.37–2.09, P < 0.001), BMI > 28 (OR 1.36, 95% CI 1.08–1.72, P = 0.009), pure LDN (OR 1.99, 95% CI 1.53–2.60, P < 0.001), multiple renal arteries (OR 2.38, 95% CI 1.83–3.10, P < 0.001) and multiple renal veins (OR 2.18, 95% CI 1.52–3.16, P < 0.001) were independent risk factors influencing prolonged operative time. The difficulty index based on these factors was calculated and categorized into three levels: low (0–2), intermediate (3–5), and high (6–8) difficulty. Operative time was significantly longer in the high difficulty group (225 min) than in the low (169 min, P < 0.001) and intermediate difficulty group (194 min, P < 0.001). The conversion rate was higher in the high difficulty group (4.4%) than in the low (2.1%, P = 0.04) and the intermediate difficulty group (3.0%, P = 0.27). No significant difference in major complications was found between the groups.ConclusionWe developed a novel grading system with simple preoperative donor factors to predict the difficulty of LDN. This grading system may help surgeons in patient selection to advance their experiences and/or teach fellows from simple to difficult LDN.

Ban- Iwate difficulty scoring system for laparoscopic liver resection- Validation in a Single centre UK cohort

Background: Evolution and wide-spreading of laparoscopic liver resection has been a drive to develop scoring systems to predict difficulty such as the Ban- Iwate scoring system. Our aim was to validate the 'Difficulty Scoring System' in a single centre UK cohort. Methods: The proposed 'difficulty scoring system' for laparoscopic liver resection (LLR) includes a three-level index of difficulty based on tumor parameters (location, size, proximity to major vessels), liver function and extend of planned liver resection. The system was validated in a single tertiary centre cohort of 123 patients who underwent LLR between 2015 and 2018. Perioperative parameters and short term outcomes were compared between the three levels of difficulty groups. Results: 123 patients who underwent LLR were classified as low (n=24), intermediate (n=68) and high (n=31) difficulty. Conversion rate was associated with the difficulty level (p=0.026). Overall complication rate was 16.7%, 18.5% and 29% in the low, intermediate and high difficulty group, respectively. Difficulty scoring system was associated with increased transfusion rate (p= 0.034). None in the low, 2 in the intermediate and 5 in the high difficulty group. Ban- Iwate classification was significantly correlated with the length of stay (p=0.027). Conclusion: Preoperative evaluation using the Ban- Iwate difficulty scoring system for laparoscopic liver resection predicted the difficulty of the operation and the postoperative outcomes. Implementing the difficulty scoring system could allow appropriate patients' selection, especially for surgeons in the beginning of their training.

Is laparoscopic hepatectomy suitable for giant hepatic hemangioma larger than 10cm in diameter?

Surgical treatment of giant hepatic hemangioma larger than 10cm in diameter often requires major laparoscopic liver resection (LLR), which is very difficult and has a high risk of bleeding. There is no consensus as to whether giant hepatic hemangioma is an indication or a contraindication for laparoscopic surgery. From 2011/09 to 2018/05, 58 patients with giant hepatic hemangioma larger than 10cm underwent laparoscopic surgery. They were divided into high-difficulty (HD) group and low-difficulty (LD) group according to the operation difficulty score. The perioperative data of the two groups were analyzed and compared. There were 30 patients in the LD group and 28 in the HD group. No differences were showed in sex, age, ASA grade, tumor size, operation time, conversion rate, intraoperative and post-operative blood transfusion rate, and post-operative complications between the two groups. The amount of bleeding in the HD group was significantly higher than that in the LD group (285.7 ± 224.0 vs 189.6 ± 157.6ml, p = 0.007). The time of hepatic hilar occlusion in the HD group was longer than that in the LD group (25.4 ± 8.8 vs 20.6 ± 7.3min, p = 0.001), and the rate of hepatic hilar occlusion in the HD group was also higher than that in the LD group (71.4% vs 33.3%, p = 0.004). The incidence of hospitalization days and discharge time in the LD group were shorter than those in the HD group (6.3 ± 1.6 vs 8.2 ± 1.4days, p = 0.000; 16.4 ± 5.5 vs 21.9 ± 4.6h, p = 0.019). There was no significant difference in enzymatic parameters between the two groups after operation. Although there are great difficulties and risks objectively, laparoscopic treatment of giant hepatic hemangioma is safe and feasible.

Trajectories and predictors of risk for mental health problems throughout childhood.

Children fluctuate in their risk for mental health-related problems. While children have demonstrated consistent trajectories for various types of mental health problems, the existence of developmental trajectories of overall risk of mental health problems has not been explored. This study aimed to identify distinct trajectories of overall mental health risk among children from ages 4-12years. A secondary objective was to identify predictors of the mental health risk trajectories. Data from the first five waves of the Longitudinal Study of Australian Children (LSAC) were used to assess mental health risk and potential predictors. The primary parent (n=3717) completed questionnaires, time-use diaries, and face-to-face interviews over the five waves. Growth mixture modeling was used to identify distinct latent trajectories of mental health risk. Multinomial logistic regression was used to identify predictors of the trajectories. Six distinct trajectories of mental health risk were identified: Low Difficulty (72.9%), Improvers (9.7%), Decliners (7.9%), Early Decliners/Late Improvers (4.7%), Early Improvers/Late Decliners (2.7%), and High Difficulty (2.2%). Child sex, sociability, parental warmth, sports participation, and household income were identified as significant predictors of mental health trajectories. There are distinct trajectories of overall risk for mental health problems during childhood. Research should focus on the High Difficulties group and the Early Improvers/Late Decliners group to address the predictors and improve access to early mental health services.

Validation of a Difficulty Scoring System for Laparoscopic Liver Resection: A Multicenter Analysis by the Endoscopic Liver Surgery Study Group in Japan

Laparoscopic liver resection (LLR) is widely used for hepatic disease treatment. Preoperative prediction of operative difficulty can be beneficial as a roadmap for surgeons advancing from simple to highly technical LLR. We performed a multicenter analysis to investigate a "difficulty scoring system" for predicting the difficulty of LLR. The proposed "difficulty scoring system" includes 3 difficulty levels based on 5 factors. The system was validated in a cohort of 2,199 patients who underwent LLR at 74 Japanese centersbetween 2010 and 2014; the difficulty level was rated as low (n= 965), intermediate (n= 891), and high (n= 343). Operative parameters, postoperative complications, and outcomes were compared according to the difficulty levels. The median operation time and blood loss were 258 minutes (range 30 to 1,275 minutes) and 75 mL (range 0 to 7,798 mL), respectively. The overall conversion rate was 5.0% (n= 110). The incidences of postoperative complications, liver failure, and in-hospital death were 5.3% (n= 116), 1.5% (n= 32), and 0.5% (n= 12), respectively. Median hospital stay was 9 days (range 1 to 189 days). Conversion rate, operation time, and blood loss showed a direct correlation with the difficulty level. A strong correlation was observed among the difficulty level, incidence of postoperative complications, and hospital stay. Incidence of postoperative liver failure and in-hospital death in the high difficulty group was higher than that in the low difficulty group. Preoperative evaluation with the "difficulty scoring system" predicted the difficulty of the operation and the postoperative outcomes of LLR. In the beginning of LLR training, surgeons should start with low difficulty-level operations.

Subtyping of Strengths and Difficulties in a Chinese Adolescent Sample: a Latent Class Analysis

The purpose of this study was to explore the subtyping of strengths and difficulties among normal Chinese adolescents using Latent Class Analysis (LCA). The Chinese version of the Strengths and Difficulties Questionnaire (SDQ-C) was administered to 4121adolescents, ages 11–18 years (M = 15.35, SD = 1.70) recruited from 12 Chinese middle schools. Obvious grouping features appeared, and the model of the three latent classes was supported. The three groups were defined as the “high difficulties group”, “uncooperative group”, and “well-adjusted group”, the three groups accounted for 34.8, 29.9, and 35.3 % of the total sample respectively. After extracting three latent classes from the data, a multivariate logistic regression model was employed to assess the relationship between the three latent classes and gender, age, parents’ marital status, and parents’ educational attainment. Further analyses revealed that compared to the well-adjusted group, the adolescents from the high difficulties group and uncooperative group were older, and had parents with unstable marriages and lower educational attainments. Significant heterogeneity in strengths and difficulties was revealed in this Chinese adolescent sample. The three- group cluster solution, based on the analyses of difficulties and strengths, provided further support for models of mental health that extend beyond the traditional medical model, revealing youth who might be missed in mental health screenings focusing only on difficulties. Further research, with different cultural samples, is needed to support these results.

Prediction of the Surgical Difficulty of Single-port Laparoscopic Cholecystectomy

The aim of this study was to use the difficulty score for a laparoscopic cholecystectomy procedure to predict the surgical difficulty of single-port laparoscopic cholecystectomy. From January 2009 to April 2011, single-port laparoscopic cholecystectomy was performed in 30 patients at our institution. The patients were evaluated using the difficulty score and classified into 3 groups: low, intermediate, and high difficulty. All surgeries were successfully completed without conversion to conventional laparoscopic surgery. A strong relationship was observed between the increasing score and longer surgical time. The mean surgical time was longer and the amount of blood loss was greater in the intermediate-difficulty and high-difficulty groups than in the low-difficulty group. Moreover, the high-difficulty group had a higher rate of insertion of an additional trocar than the low-difficulty group. Thus, the difficulty of single-port laparoscopic cholecystectomy is well predicted using the difficulty score.

Risk of Psychological Difficulties Among Children Raised by Custodial Grandparents

Although custodial grandchildren are believed to be at greater risk of emotional and behavioral problems than children in general, scant research has examined this important public health issue. This study involves data from 733 custodial grandmothers participating in a study funded by the National Institute of Mental Health on custodial grandparenting and 9,878 caregivers from the 2001 National Health Interview Survey (NHIS) who completed the Strengths and Difficulties Questionnaire (SDQ) in reference to target children between ages four and 17. These two data sets were used to determine if custodial grandmothers report greater emotional and behavioral difficulties, as measured by the SDQ, for custodial grandchildren than do caregivers of children from the NHIS normative sample. Custodial grandchildren fared worse than children from the NHIS sample across all domains measured by the SDQ subscales, regardless of the child's gender and whether reporters were recruited by population-based or convenience sampling methods. Comparisons within the sample of 733 custodial grandmothers showed that higher levels of difficulties were reported when grandmothers were caring for boys, were recruited by convenience versus population-based sampling, and were white. Comparisons of the banded scores computed for each SDQ subscale suggested that custodial grandchildren have different cutoff points than children in the general population for a likely diagnosis of a psychiatric disorder. Similar to other children in kinship care arrangements, custodial grandchildren are reported by their caregivers to have higher levels of behavioral and emotional disturbances than children in the overall U.S. population.

Discriminating Between Task-Relevant and Task-Irrelevant Stimuli

Abstract The effect that the difficulty of the discrimination between task-relevant and task-irrelevant stimuli has on the relationship between skin conductance orienting and secondary task reaction time (RT) was examined. Participants (N = 72) counted the number of longer-than-usual presentations of one shape (task-relevant) and ignored presentations of another shape (task-irrelevant). The difficulty of discriminating between the two shapes varied across three groups (low, medium, and high difficulty). Simultaneous with the primary counting task, participants performed a secondary RT task to acoustic probes presented 50, 150, and 2000 ms following shape onset. Skin conductance orienting was larger, and secondary RT at the 2000 ms probe position was slower during task-relevant shapes than during task-irrelevant shapes in the low-difficulty group. This difference declined as the discrimination difficulty was increased, such that there was no difference in the high-difficulty group. Secondary RT was slower during task-irrelevant shapes than during task-relevant shapes only in the medium-difficulty group - and only at the 150 ms probe position in the first half of the experiment. The close relationship between autonomic orienting and secondary RT at the 2000 ms probe position suggests that orienting reflects the resource allocation that results from the number of matching features between a stimulus input and a mental representation primed as significant.

Discriminating Between Task-Relevant and Task-Irrelevant Stimuli The Effects on Autonomic Orienting and Secondary Task Reaction Time

The effect that the difficulty of the discrimination between task-relevant and task-irrelevant stimuli has on the relationship between skin conductance orienting and secondary task reaction time (RT) was examined. Participants (N = 72) counted the number of longer-than-usual presentations of one shape (task-relevant) and ignored presentations of another shape (task-irrelevant). The difficulty of discriminating between the two shapes varied across three groups (low, medium, and high difficulty). Simultaneous with the primary counting task, participants performed a secondary RT task to acoustic probes presented 50, 150, and 2000 ms following shape onset. Skin conductance orienting was larger, and secondary RT at the 2000 ms probe position was slower during task-relevant shapes than during task-irrelevant shapes in the low-difficulty group. This difference declined as the discrimination difficulty was increased, such that there was no difference in the high-difficulty group. Secondary RT was slower during task-irrelevant shapes than during task-relevant shapes only in the medium-difficulty group - and only at the 150 ms probe position in the first half of the experiment. The close relationship between autonomic orienting and secondary RT at the 2000 ms probe position suggests that orienting reflects the resource allocation that results from the number of matching features between a stimulus input and a mental representation primed as significant.

The effect of problem difficulty, locus of control, and sex on task persistence.

The purpose of this study was to investigate the influence of problem difficulty, instructional set, locus of control, and sex of S on time expended by college students to solve a puzzle. Three groups of college students (N = 120), each equated for test scores on internal and external locus of control and for sex, were divided as follows: the members of one (n = 40) were told that the problem they were being asked to solve would be difficult; the members of a second were told the problem would be easy; and the members of a third were given no instructions on the difficulty of the problem. The task of the Ss was to form a pattern from a set of small plastic shapes; however, the problem was actually unsolvable. The response measure was the length of time the Ss chose to devote to solving the problem. The results revealed that the Ss in the high difficulty group devoted more time to the task than the Ss in the low difficulty (p less than .06) and control conditions (p less than .05). All other effects were nonsignificant. The results suggested that the Ss in the high-difficulty group perceived their failure to solve the problem to be less of a threat to their self-esteem than did the Ss in the other groups, and as a result devoted more time to the task.