Support vector machines categorize the scaling of human grip configurations

In previous work (Cesari & Newell, 2002), we used a graphical dimensional analysis to show that grip transitions obey the body-scaled relation K = lnL(o) + InM(o)h/(a + bM(h) + cL(h)), where L. and Mo are the object's length and mass, and Lh and Mh the length and mass of the grasper's hand. However, the generality of the equation was limited by the ad hoc graphical method that defined the lines for grip separation and by the assumption that these lines be negatively sloped and parallel to one another. This article reports an independent test of this relation by the geometrical and statistical categorization of body-scaled invariants for the transition of human grip configurations through support vector machines (SVMs). The SVM analysis confirmed the fit of linear, negatively sloped, and approximately parallel transition boundaries in the scaling of human grip configuration within a single hand. The SVM analysis has provided a theoretical refinement to the scaling model of human grip configurations.     

THE MEANING OF DREAMS IN THE PSYCHOTIC STATE: THEORETICAL CONSIDERATIONS AND CLINICAL APPLICATIONS

The authors consider that the Freudian theory of dreams is not directly applicable to psychotic and borderline patients with their constantly varying states of mental integration. Because these patients' dreams lack associations, the usual psychoanalytic approach cannot be used to ascertain their meaning. After reviewing the literature on the specific quality of dreams in the psychotic state, the authors point out that such dreams have nothing to do with the metaphorical language of the dream work but instead express the concreteness of the hallucinatory construction. For this reason, a dream's meaning may fail to be understood by the patient even if it seems clear to an observer. Yet the analyst's reception of a 'psychotic dream' is a unique and essential source of valuable information on the manner of construction of the delusional system, allowing analytic work on the psychotic nucleus. In the authors'view, such dreams may help the analyst and the patient— while still lucid—to acquire insight, thus affording a stable foundation for emergence from psychosis. The paper includes some case histories, in one of which a psychotic female patient is enabled by work on dreams to reconstruct a psychotic episode and thereby to ward off an imminent fresh lapse into psychosis.     

Two Studies Examining the Error Theory Underlying the Measurement Model of the Verbal Aggressiveness Scale

Meta‐analysis indicates moderate correlations between the Verbal Aggressiveness Scale (VAS) and other self‐report measures but near‐zero correlations with behavioral measures. Accurately interpreting correlations between the VAS and other variables, however, requires an examination of the untested error theory underlying the measurement model for the VAS. In two separate studies, the results of single‐factor correlated uniqueness confirmatory factor analytic models revealed a pattern of significant error covariances indicating that VAS item scores are confounded by systematic error attributable to multiple unspecified latent effects. After pruning the item sets, we identified 4 items that were free of latent variable influences other than trait verbal aggressiveness. Implications for interpreting the verbal aggressiveness literature are discussed along with recommendations for revising the VAS.     

The impact of perceived effort–reward imbalance on workplace bullying: also a matter of organizational identification

Work environments characterized by inadequate work conditions have been widely recognized as being particularly prone to the occurrence and exacerbation of bullying behavior. Accordingly, this longitudinal study aimed to explore whether the impact of effort–reward imbalance (ERI) on workplace bullying was mediated by a lower perception of organizational justice, and whether the association between ERI and perceptions of justice was moderated by organizational identification. In the current study, a sample of N = 195 Spanish employees from different occupational sectors filled in an online questionnaire at two different times with a time lag of 8 months. In line with the hypothesized moderated mediation model, results showed that organizational justice mediated the impact of ERI on workplace bullying. Moreover, the effect of perceived ERI on organizational justice was stronger for employees with low organizational identification. Overall, this study can contribute to better understanding how and when ERI boosts the risk of workplace bullying. Accordingly, early intervention designed to buffer the negative effects of ERI should focus on increasing individual levels of organizational identification.     

Use of the ten-point clock test to compare executive functioning across 24 months in patients with subcortical vascular dementia

The Ten-point Clock Test can be used to identify early forms of Alzheimer's disease because it is reliable, well accepted, and easily administered at the bedside. Nevertheless, its clinical role in the detection of early dementia and its correlations with other cognitive processes is still under investigation. Vascular dementia is an uncertain nosological entity, in which unevenly distributed patterns of cognitive deficits comprising slowing of cognitive processing and impairment of executive function occur. The present study assessed how the Clock Test scores correlated with a number of other neuropsychological and functional tests in a sample of 144 patients with vascular dementia, who were followed for a period of 24 mo. At baseline, at 12 mo. and at 24 mo. subjects were administered a battery of tests, including the Mini-Mental State Examination, word fluency, visuospatial skills, an evaluation of hetero- and autotopognosia (knowledge of self), the Proverbs Test, and the Ten-point Clock Test. For these patients scores on the Clock Test correlated significantly with semantic abilities, with abstract reasoning capacities, visuospatial perception, and with right and left recognition.     

Analyzing aphasia data in a multidimensional symptom space

The utility of single-case vs. group studies has been debated in neuropsychology for many years. The purpose of the present study is to illustrate an alternative approach to group studies of aphasia, in which the same symptom dimensions that are commonly used to assign patients to classical taxonomies (fluency, naming, repetition, and comprehension) are used as independent and continuous predictors in a multivariate design, without assigning patients to syndromes. One hundred twenty-six Italian-speaking patients with aphasia were first classified into seven classic aphasia categories, based on fluency, naming, auditory comprehension, and repetition scales. There were two goals: (1) compare group analyses based on aphasia types with multivariate analyses that sidestep classification and treat aphasic symptoms as continuous variables; (2) present correlation-based outlier analyses that can be used to identify individuals who occupy unusual positions in the multivariate "symptom space." In the service of the first goal, group performance on an external validation measure (the Token Test) was assessed in three steps: analyses of variance based on aphasia type, regressions using the same cut-offs for fluency, naming, comprehension and repetition as independent but dichotomous predictors, and regressions using the same subscales as continuous predictors (with no cut-offs). More variance in Token Test performance was accounted for when symptoms were treated as continuous predictors than with the other two methods, though use of independent but dichotomous predictors accounted for more variance than aphasia taxonomies. Thus, if we by-pass classical taxonomies and treat patients as points in a multidimensional symptom space, better predictions are obtained. Outlier analyses show that group results depend on heterogeneity among patients, which can be used as a search tool to identify potentially interesting dissociations. Hence this multivariate group approach is complementary to and compatible with single-case methods.     

Coordinate high-frequency pattern of stimulation and calcium levels control the induction of LTP in striatal cholinergic interneurons

Current evidence appoints a central role to cholinergic interneurons in modulating striatal function. Recently, a long-term potentiation (LTP) of synaptic transmission has been reported to occur in these neurons. The relationship between the pattern of cortico/thalamostriatal fibers stimulation, the consequent changes in the intracellular calcium concentration ([Ca2+]i), and the induction of synaptic plasticity was investigated in striatal cholinergic interneurons from a rat corticostriatal slice preparation by means of combined electrophysiological intracellular recordings and microfluorometric techniques. Different protocols of stimulation were considered, varying both the frequency and the duration of the train of stimuli. High-frequency stimulation (HFS) (three trains at 100 Hz for 3 sec, 20-sec interval) induced a rise in [Ca2+]i, exceeding by fivefold the resting level, and caused a LTP of synaptic transmission. Tetanic stimulation delivered at lower frequencies (5-30 Hz) failed to induce long-term changes of synaptic efficacy. The observed elevation in [Ca2+]i during HFS was primarily mediated by L-type high-voltage activated (HVA)-Ca2+ channels, as it was fully prevented by nifedipine. Conversely, blockade of NMDA and AMPA glutamate receptor did not affect either LTP or the magnitude of the [Ca2+]i rise. Interestingly, the pharmacological analysis of the post-tetanic depolarizing postsynaptic potential (DPSP) revealed that LTP was attributable, to a large extent, to the potentiation of the GABA(A)-mediated component. In conclusion, the expression of LTP in striatal cholinergic interneurons is a selective response to a precise stimulation pattern of induction requiring a critical rise in [Ca2+]i.     

Discrimination of voice versus place contrasts in aphasia

A phoneme discrimination test based upon CCVC (consonant-consonant-vowel-consonant) syllables was administered to 36 aphasics, 91 brain-damaged subjects, and 42 normal controls, in normal listening conditions. Errors in the discrimination of voice and place contrasts were determined, and the scores (voice-minus-place errors) obtained by the four experimental groups were compared statistically. Aphasic patients, when compared with the other groups, show a greater difficulty in discriminating place than voice contrasts. Some implications of these findings are discussed.     

Social cognition and real-life functioning in patient samples with 22q11.2 deletion syndrome with or without psychosis,compared to a large sample of patients with schizophrenia only and healthy controls

Patients with the 22q11.2 deletion syndrome (DS) show an increased risk of developing a psychotic illness lifetime. 22q11.2DS may represent a reliable model for studying the neurobiological underpinnings of schizophrenia. The study of social inference abilities in a genetic condition at high risk for psychosis, like 22q11.2DS, may shed light on the relationships between neurocognitive processes and patients' daily general functioning. The study sample consisted of 1736 participants, divided into four groups: 22q11.2DS patients with diagnosis of psychotic disorder (DEL SCZ, N = 20); 22q11.2DS subjects with no diagnosis of psychosis (DEL, N = 43); patients diagnosed with schizophrenia without 22q11.2DS (SCZ, N = 893); and healthy controls (HC, N = 780). Social cognition was assessed through The Awareness of Social Inference Test (TASIT) and general functioning through the Specific Levels of Functioning (SLoF) scale. We analysed data through regression analysis. The SCZ and DEL groups had similar levels of global functioning; they both had significantly lower SLoF Total scores than HC (p < .001); the DEL SCZ group showed significantly lower scores compared to the other groups (SCZ, p = .004; DEL, p = .003; HC, p < .001). A significant deficit in social cognition was observed in the three clinical groups. In the DEL SCZ and SCZ groups, TASIT scores significantly predicted global functioning (p < .05). Our findings of social cognition deficit in psychosis-prone patients point to the possible future adoption of rehabilitation programmes, like Social Skills Training and Cognitive Remediation, during premorbid stages of psychosis.