Instability of hierarchical cluster analysis due to input order of the data: the PermuCLUSTER solution

Hierarchical agglomerative cluster analysis (HACA) may yield different solutions under permutations of the input order of the data. This instability is caused by ties, either in the initial proximity matrix or arising during agglomeration. The authors recommend to repeat the analysis on a large number of random permutations of the rows and columns of the proximity matrix and select a solution with the highest goodness-of-fit. This approach was implemented in an SPSS add-in, PermuCLUSTER, which can perform all HACA methods of SPSS. Analyses of 2 data sets show that (a) results are affected by input order, (b) instability in one method co-occurs with instability in other methods, and (c) some instability effects are more dramatic because they occur at higher agglomeration levels.     

Clamped Corticosterone (B) Reveals the Effect of Endogenous B on Both Facilitated Responsivity to Acute Restraint and Metabolic Responses to Chronic Stress

To determine the effects of both corticosterone (B) and chronic stressors on acute ACTH responses to restraint, young male rats were exposed to streptozotocin-induced diabetes, cold (5-7 degreesC) or intracerebroventricular (icv) neuropeptide Y (NPY) for 5 d and then exposed to restraint within 2 h after lights on. Two groups of rats were studied: intact and adrenalectomized replaced with B pellets that maintained plasma B in the normal mean 24-h range of intact rats. In addition to ACTH and B responses to restraint on d 5, body weight, food intake, fat depots, glucose and other hormones were measured to determine the role of stress-induced elevations in B on energy balance. ACTH responses to restraint were normal in intact rats subjected to diabetes or cold. By contrast, there was no ACTH or B response to restraint in NPY-infused intact rats. All 3 groups of chronically stimulated adrenalectomized rats with clamped B had facilitated ACTH responses to restraint compared to their treatment controls. Overall food intake increased in all groups of stressed rats; however, augmented intake occurred only during the light in intact rats and equally in the light and dark in B-clamped rats. White adipose depot weights were decreased by both diabetes and cold and increased by NPY in intact rats; the decreases with cold and increases with NPY were both blunted and changes in fat stores were not significant in adrenalectomized, B-clamped rats. We conclude that: 1. diabetes- and cold-induced facilitation of restraint-induced afferent input to hypothalamic control of the hypothalamo-pituitary-adrenal (HPA) axis is opposed in intact rats by the elevated feedback signal of B secretion; 2. NPY does not induce facilitation of afferent stress pathways; 3. chronic stimulation of the HPA axis induces acute hyperresponsiveness of hypothalamic neurons to restraint provided that the afferent input of this acute stimulus is not prevented by B feedback; 4. stimulus-induced elevations in B secretion result in day-time feeding; 5. insensitivity of both caloric efficiency and white fat stores to chronic stress in adrenalectomized, B-clamped rats results from loss of normally variable B levels.     

The DAPP–SF as a Screener for Personality Disorder in a Forensic Setting

Studies on the Dimensional Assessment of Personality Pathology–Short Form (DAPP–SF) have shown its ability to identify treatment-seeking patients with personality disorders. This study focuses on its screening potential for personality disorder in 89 criminal suspects (77 men, 12 women; M age = 37.0 years) undergoing residential pretrial psychological assessments in a high-security setting. It was expected that Structured Interview for DSM–IV Personality (SIDP–IV) criteria met for personality disorder(s) would be associated with higher DAPP–SF scores. A floor effect was found in DAPP–SF scores: The forensic population reported less personality pathology than the general population. Only moderate associations between DAPP–SF and SIDP–IV outcome were found. Receiver operating characteristic analysis showed that some DAPP–SF subscales did not exceed chance level in their ability to screen for personality disorders. It is concluded that the DAPP–SF has limited usefulness as a screener for personality disorders in a forensic pretrial setting. Alternative forensic screening instruments are presented.     

Sad and happy emotion discrimination in music by children with cochlear implants

Children using cochlear implants (CIs) develop speech perception but have difficulty perceiving complex acoustic signals. Mode and tempo are the two components used to recognize emotion in music. Based on CI limitations, we hypothesized children using CIs would have impaired perception of mode cues relative to their normal hearing peers and would rely more heavily on tempo cues to distinguish happy from sad music. Study participants were children with 13 right CIs and 3 left CIs (M = 12.7, SD = 2.6 years) and 16 normal hearing peers. Participants judged 96 brief piano excerpts from the classical genre as happy or sad in a forced-choice task. Music was randomly presented with alterations of transposed mode, tempo, or both. When music was presented in original form, children using CIs discriminated between happy and sad music with accuracy well above chance levels (87.5%) but significantly below those with normal hearing (98%). The CI group primarily used tempo cues, whereas normal hearing children relied more on mode cues. Transposing both mode and tempo cues in the same musical excerpt obliterated cues to emotion for both groups. Children using CIs showed significantly slower response times across all conditions. Children using CIs use tempo cues to discriminate happy versus sad music reflecting a very different hearing strategy than their normal hearing peers. Slower reaction times by children using CIs indicate that they found the task more difficult and support the possibility that they require different strategies to process emotion in music than normal.     

阅读预期对快速阅读理解的影响的实验研究

探讨阅读预期对快速阅读的理解水平与进程的影响。实验１探讨阅读预期对快速阅读理解水平的影响。阅读文章前分别给予被试正确、中性与误导的标题提示,结果表明,不同类型的标题提示对快速阅读的理解成绩有显著的影响,而对正常速度阅读的理解成绩影响效果不显著。实验２探讨阅读预期对快速阅读过程的词句加工程度的影响。结果表明,对优生来说,正确标题提示组发现文章中锗字的成绩显著低于误导标题提示组,差生的不同标题提示组发现错字的成绩差异不显著。两个实验的结果初步表明,快速阅读文章过程会更多地利用概念推动,较少地需要材料信息。     

Development of Time Concepts: Differentiating Clock and Calendar from Apparent Durations

To investigate the role of perception and stress on time concepts, the real-time and apparent durations of common events varying in length from 30 s to 4 years were rated by kindergarten through 12th-grade pupils, college students, professors, and stress-impaired adults (N = 1,788). The events were pleasant, neutral or unpleasant; either directly perceptible and of specific duration or perceptually vague; and happened either to oneself or to someone else. Second graders differentiated apparent from real-time durations and, therefore, already had an abstract concept of time. As predicted from differentiation theory (Gibson, E. J., 1969; Gibson, J. J., 1966, 1983), longer durations were acquired later than shorter ones; perceptually-vague durations were acquired later than clearly perceptible ones of similar length; and, as Neisser (1976) also suggested, stress did not lead to regression, nor did the personal-impersonal dimension make a difference during childhood.     

Mental Disorders,Comorbidity, and Pre‐enlistment Suicidal Behavior Among New Soldiers in the U.S. Army: Results from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS)

We examined the associations between mental disorders and suicidal behavior (ideation, plans, and attempts) among new soldiers using data from the New Soldier Study (NSS) component of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS; N = 38,507). Most new soldiers with a pre‐enlistment history of suicide attempt reported a prior mental disorder (59.0%). Each disorder examined was associated with increased odds of suicidal behavior (ORs = 2.6–8.6). Only PTSD and disorders characterized by irritability and impulsive/aggressive behavior (i.e., bipolar disorder, conduct disorder, oppositional defiant disorder, and attention‐deficit/hyperactivity disorder) predicted unplanned attempts among ideators. Mental disorders are important predictors of pre‐enlistment suicidal behavior among new soldiers and should figure prominently in suicide screening and prevention efforts.