Data-driven methodology illustrating mechanisms underlying word list recall: Applications to clinical research.

Objective: Word list learning tasks such as the California Verbal Learning Test (CVLT; Delis, Kramer, Kaplan, & Ober, 1987) are widely used to investigate recall strategies. Participants who recall the most words generally employ semantic techniques, whereas those with poor recall (e.g., patients with schizophrenia) rely on serial techniques. However, these conclusions are based on formulas that assume that categories reflect semantic associations, bind strategy to overall performance, and neglect strategy changes over 5 trials. Therefore, we derived novel measures—independent of recall performance—to compute strategies across trials and identify whether diagnosis predicts recall strategy. Method: Participants were included on the basis of performance on the CVLT (i.e., total words recalled over 5 trials). The 50 highest and 50 lowest performers among healthy volunteers (n = 100) and patients with schizophrenia (n = 100) were selected. Novel measures of recall and transition probability were calculated and analyzed by permutation tests. Results: Recall patterns and strategies of patients resembled those of controls with similar performance levels: Regardless of diagnosis, low performers were more likely to recall the first 2 and last 4 items from the list; high performers increased engagement of semantically based transitions across the 5 trials, whereas low performers did not. Conclusions: Cognitive strategy must be considered independent of overall performance before attributing poor performance to degraded learning processes. Our results demonstrate the importance of departing from global scoring techniques, especially when working with clinical populations such as patients with schizophrenia for whom episodic memory deficits are a hallmark feature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

氧化环境对金属化金刚石热稳定性能的影响

采用化学气液相处理（CVLT）技术在SMD35金刚石表面制备Cr、Ni等金属膜,经X－射线衍射分析,金刚石表面生成了Cr3C2碳化物,实现了金刚石与镀层金属的化学键结合;对经CVLT技术金属化的金刚石和未镀膜金刚石进行了高温下表面形貌观察、组织结构、热失重和抗压强度测试分析,结果表明：经1000℃高温加热后,表面金属化金刚石比未镀膜金刚石失重率低近1／4,抗压强度提高约1／3。     

Early patterns of verbal memory impairment in children treated for medulloblastoma.

Children treated for medulloblastoma demonstrate a variety of cognitive deficits in addition to white matter and hippocampal neuropathology. This study examined 40 children treated for medulloblastoma as compared with 40 demographically matched controls on the California Verbal Learning Test-Children's Version (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1994). Results revealed significantly poorer performance on indices of word recall in the patient group as compared with the controls in addition to milder but still significantly poorer recognition memory. These findings suggest that children treated for medulloblastoma demonstrate a mixed profile of memory impairment consisting of both retrieval and recognition deficits. Implications of these findings for understanding neurobehavioral sequelae within pediatric medulloblastoma populations and for designing educational and remediation strategies to be used with these children are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)