Measuring and modeling distraction by self-referential processing in a complexworking memory span task

Two experiments using novel complex working memory spantasks were performed, both requiring the participants toremember a span of letters whilst being distracted by theprocessing of words. Word processing could either be self-referential (SRP) or not. In the first experiment recallperformance was compared between SRP and non-SRPconditions using the same words. In the second experiment,we compared SRP and non-SRP in two tasks equalized insemantic processing but using different words. In bothexperiments recall performance was significantly lower afterSRP compared to non-SRP, indicating that SRP has adisruptive effect on the recall task. A cognitive modelimplemented in PRIMs, using goal competition during SRP,interfering with rehearsal of letters, could account for theobserved experimental results. If SRP interferes withsubsequent tasks in this manner it should also interfere withtasks other than recall, such as SRP occurring in daily life

Ambulatory Monitoring of Activities and Motor Symptoms in Parkinson's Disease

Ambulatory monitoring of motor symptoms in Parkinson's disease (PD) can improve our therapeutic strategies, especially in patients with motor fluctuations. Previously published monitors usually assess only one or a few basic aspects of the cardinal motor symptoms in a laboratory setting. We developed a novel ambulatory monitoring system that provides a complete motor assessment by simultaneously analyzing current motor activity of the patient (e.g., sitting, walking, etc.) and the severity of many aspects related to tremor, bradykinesia, and hypokinesia. The monitor consists of a set of four inertial sensors. Validity of our monitor was established in seven healthy controls and six PD patients treated with deep brain stimulation (DBS) of the subthalamic nucleus. The patients were tested at three different levels of DBS treatment. Subjects were monitored while performing different tasks, including motor tests of the Unified PD Rating Scale (UPDRS). Output of the monitor was compared to simultaneously recorded videos. The monitor proved very accurate in discriminating between several motor activities. Monitor output correlated well with blinded UPDRS ratings during different DBS levels. The combined analysis of motor activity and symptom severity by our PD monitor brings true ambulatory monitoring of a wide variety of motor symptoms one step close

The impact of low skeletal muscle mass in abdominal surgery

Although perioperative outcome in transplant and surgical oncology patients has greatly improved during the last decades, preoperative risk assessment remains of utmost importance to further improve outcomes and adapt patient-tailored treatment strategies. Low skeletal muscle mass is associated with increased age and disease, such as cancer and liver disease. Considering the increasing age of the population, the increasing incidence of cancer, the remaining shortage of donor livers, and the increased surgical and medical treatment options, skeletal muscle mass could be an important addition used for risk assessment. Moreover, it may be a therapeutic target to improve treatment outcomes. Therefore, the aim of this thesis was to investigate the applicability of skeletal muscle mass measurements and to define the relevance of decreased skeletal muscle mass in surgical oncology and liver transplant patients

Intrahepatic cholangiocarcinoma: Current perspectives

Intrahepatic cholangiocarcinoma (ICC) is the second most common malignancy arising from the liver. ICC makes up about 10% of all cholangiocarcinomas. It arises from the peripheral bile ducts within the liver parenchyma, proximal to the secondary biliary radicals. Histologically, the majority of ICCs are adenocarcinomas. Only a minority of patients (15%) present with resectable disease, with a median survival of less than 3 years. Multidisciplinary management of ICC is complicated by large differences in disease course for individual patients both across and within tumor stages. Risk models and nomograms have been developed to more accurately predict survival of individual patients based on clinical parameters. Predictive risk factors are necessary to improve patient selection for systemic treatments. Molecular differences between tumors, such as in the epidermal growth factor receptor status, are promising, but their clinical applicability should be validated. For patients with locally advanced disease, several treatment strategies are being evaluated. Both hepatic arterial infusion chemotherapy with floxuridine and yttrium-90 embolization aim to downstage locally advanced ICC. Selected patients have resectable disease after downstaging, and other patients might benefit because of postponing widespread dissemination and biliary obstruction

The resource-availability model of distraction and mind-wandering

This article presents a cognitive model of distraction and mind-wandering that combines and formalizes several existing theories. It assumes that task-related goals and opportunities for distraction are continuously in competition for mental resources. If the task-related goal does not need a particular resource at a particular moment, the likelihood that it is captured by a distraction is high. We applied this model to explain the results of three distraction experiments that differ from each other in a number of ways. The first experiment is a slow-paced mind-wandering study; the main result is that less mind-wandering occurs if subjects have to maintain an item in working memory. The second experiment is a working memory task in which mind-wandering is triggered by the presence of self-referential words in a secondary task; these words increase mental elaboration and reduce memory performance. The third experiment is a mental arithmetic/ memory/visual attention task, in which subjects became more distracted by a flanking (irrelevant) video as the task increased in complexity: as subjects need more time to think, they leave the visual resource vulnerable to distraction. Although these phenomena have been treated separately in the literature, we show that these phenomena can be explained by a single comprehensive model that is based on the assumption that distractions target unused cognitive resources

Impact of sarcopenia on clinical outcomes for patients with resected hepatocellular carcinoma:a retrospective comparison of Eastern and Western cohorts

BACKGROUND: Patient fitness is important for guiding treatment. Muscle mass, as a reflection thereof, can be objectively measured. However, the role of East-West differences remains unclear. Therefore, we compared the impact of muscle mass on clinical outcomes after liver resection for hepatocellular carcinoma (HCC) in a Dutch [the Netherlands (NL)] and Japanese [Japan (JP)] setting and evaluated the predictive performance of different cutoff values for sarcopenia. METHOD: In this multicenter retrospective cohort study, patients with HCC undergoing liver resection were included. The skeletal muscle mass index (SMI) was determined on computed tomography scans obtained within 3 months before surgery. The primary outcome measure was overall survival (OS). Secondary outcome measures were: 90-day mortality, severe complications, length of stay, and recurrence-free survival. The predictive performance of several sarcopenia cutoff values was studied using the concordance index (C-index) and area under the curve. Interaction terms were used to study the geographic effect modification of muscle mass. RESULTS: Demographics differed between NL and JP. Gender, age, and body mass index were associated with SMI. Significant effect modification between NL and JP was found for BMI. The predictive performance of sarcopenia for both short-term and long-term outcomes was higher in JP compared to NL (maximum C-index: 0.58 vs. 0.55, respectively). However, differences between cutoff values were small. For the association between sarcopenia and OS, a strong association was found in JP [hazard ratio (HR) 2.00, 95% CI [1.230-3.08], P =0.002], where this was not found in NL (0.76 [0.42-1.36], P =0.351). The interaction term confirmed that this difference was significant (HR 0.37, 95% CI [0.19-0.73], P =0.005). CONCLUSIONS: The impact of sarcopenia on survival differs between the East and West. Clinical trials and treatment guidelines using sarcopenia for risk stratification should be validated in race-dependent populations prior to clinical adoption.</p