Ergonomic comparison of operating a built-in touch-pad pointing device and a trackball mouse on posture and muscle activity

This study examined the effects of operating a built-in touch-pad pointing device and a trackball mouse on participants' completion times, hand positions during operation, postural angles, and muscle activities. 8 young men were asked to perform a cursor travel task on a notebook computer using both 60- and 80-cm high table conditions. Analysis showed that the trackball mouse significantly decreased completion times. Participants selected a hand position farther from the table edge and larger elbow angle for the trackball mouse than for the built-in touch-pad pointing device. Participants' neck, thoracic, and arm angles, or splenius capitis, trapezius, deltoid, and erector spinae muscle activities were not significantly affected by the devices, but table height significantly affected participants' completion times, hand positions, and postural angles.     

Role of the inertial eigenvectors in proprioception near the limits of arm adduction range of motion

Common everyday activities such as reaching for a cup, combing one's hair, or positioning a tool involve the accurate registration of the limb's orientation relative to the body and the environment. Past work has demonstrated that the ability of humans to perceive the spatial orientation of an occluded arm is tied to the arm's inertial eigenvectors, invariant mechanical parameters corresponding to a limb's axes of rotational symmetry. In a recent study participants pointed to visible targets while the arms' inertial eigenvectors were displaced by asymmetrically weighted splints. The lack of an effect of those splints on pointing error led them to conclude that inertial eigenvectors are not the primary invariants used for proprioception. However, their data suggested an effect of the eigenvectors, but only for conditions in which pointing did not require placing the arm near the limits of shoulder adduction range of motion. In the present study we found a significant effect of displacing the eigenvector for all tested arm angles, regardless of degree of shoulder adduction. Overall, the results supported the hypothesis that proprioception is based on sensitivity to the limb's inertial eigenvectors, with no reduction of the eigenvector effect when adducting the arm so as to reach far across the body midline.     

"Tip of the fingers" experiences by deaf signers: insights into the organization of a sign-based lexicon

The "tip of the fingers" phenomenon (TOF) for sign language parallels the "tip of the tongue" phenomenon (TOT) for spoken language. During a TOF, signers are sure they know a sign but cannot retrieve it. Although some theories collapse semantics and phonology in sign language and thus predict that TOFs should not occur, TOFs were elicited in the current study. Like TOTs, TOFs often resolve spontaneously, commonly involve targets that are proper names, and frequently include partial access to phonology. Specifically, signers were more likely to retrieve a target sign's handshape, location, and orientation than to retrieve its movement. Signers also frequently recalled the first letter of a finger-spelled word. The existence of TOFs supports two-stage retrieval and a division between semantics and phonology in American Sign Language. The partial phonological information available during TOFs suggests that phonological features are accessed more simultaneously during lexical access for signed language than during lexical access for spoken language.     

Bilingualism affects picture naming but not picture classification

Bilinguals named pictures in their dominant language more slowly (and with more errors) than did monolinguals. In contrast, bilinguals named the same pictures as quickly as did monolinguals on the fifth presentation (in Experiment 2) and classified them (as human made or natural) as quickly and accurately as did monolinguals (in Experiment 1). In addition, bilinguals retrieved English picture names more quickly if they knew the name in both Spanish and English (on the basis of a translation test that bilinguals completed after the timed tasks), and monolingual response times for the same materials suggested that this finding was not obtained simply because names that were easier to translate were easier in general. These findings suggest that bilinguals differ from monolinguals at a postconceptual processing level, that implicit activation of lexical representations in the nontarget language can facilitate retrieval in the target language, and that being bilingual is analogous to having a lexicon full of lower frequency words, relative to monolinguals.     

The Role of Temperament in the Etiology of Child Psychopathology

A substantial proportion of children and adolescents come to suffer from psychological disorders. This article focuses on the temperament factors that are involved in the pathogenesis of child psychopathology. It is argued that besides the reactive temperament factor of emotionality/neuroticism, the regulative process of effortful control also plays an important role in the etiology and maintenance of internalizing and externalizing problems in youths. More specifically, vulnerability to child psychopathology is determined by a temperament that is characterized by high levels of emotionality/neuroticism and low levels of effortful control. Models are hypothesized in which reactive and regulative temperament factors either have interactive or additive effects on the development of psychological disorders in children, and conceptualized in terms of a developmental psychopathology perspective. Directions for future research and clinical implications of this temperamental view on psychopathology are discussed.     

Associations in the course of personality disorders and Axis I disorders over time

In this study, the authors examined time-varying associations between schizotypal (STPD), borderline (BPD), avoidant (AVPD), or obsessive-compulsive (OCPD) personality disorders and co-occurring Axis I disorders in 544 adult participants from the Collaborative Longitudinal Personality Disorders Study. The authors tested predictions of specific longitudinal associations derived from a model of crosscutting psychobiological dimensions (L. J. Siever & K. L. Davis, 1991) with participants with the relevant Axis I disorders. The authors assessed participants at baseline and at 6-, 12-, and 24-month follow-up evaluations. BPD showed significant longitudinal associations with major depressive disorder and posttraumatic stress disorder. AVPD was significantly associated with anxiety disorders (specifically social phobia and obsessive-compulsive disorder). Two of the four personality disorders under examination (STPD and OCPD) showed little or no association with Axis I disorders.     

The effects of motor neurone disease on language: further evidence

It might sound surprising that Motor Neurone Disease (MND), regarded still by many as the very example of a neurodegenerative disease affecting selectively the motor system and sparing the sensory functions as well as cognition, can have a significant influence on language. In this article we hope to demonstrate that language dysfunction is not only a pronounced and well documented symptom in some MND patients but also that the study of language in MND can address interesting theoretical questions about the representation of language and conceptual knowledge in the brain. After a brief introduction delineating clinical and pathological features of the disease we discuss the evidence available in the literature for language dysfunction in MND. We then present linguistic data from our own study of seven patients with MND/dementia/aphasia syndrome focusing on the dissociation between noun and verb processing. To illustrate the clinical, neuropsychological and linguistic aspects of MND we describe in more detail the patient E.N., a pathologically confirmed case of MND/dementia. Finally, we attempt to characterise the nature of the linguistic impairment in MND in the light of current debates about the mechanisms underlying noun/verb dissociation.     

Decursin from Angelica gigas mitigates amnesia induced by scopolamine in mice

We previously reported that a total methanolic extract of the underground part of Angelica gigas Nakai (Umbelliferae) (here-in-after abbreviated AG) significantly inhibited acetylcholinesterase (AChE) activity. We characterized 12 coumarin derivatives including both decursin and decursinol from extracts of AG. In this study, we evaluated the anti-amnestic activity of decursin, a major coumarin constituent isolated from AG, in vivo using ICR mice with amnesia induced by scopolamine (1 mg/kg body weight, s.c.). Decursin, when administered to mice at 1 and 5 mg/kg body weight i.p., significantly ameliorated scopolamine-induced amnesia as measured in both the passive avoidance test and the Morris water maze test. Moreover, decursin significantly inhibited AChE activity by 34% in the hippocampus of treated mice. These results indicate that decursin may exert anti-amnestic activity in vivo through inhibition of AChE activity in the hippocampus.     

Children's nighttime fears: parent-child ratings of frequency, content, origins, coping behaviors and severity

The present study investigated nighttime fears in normal school children aged 4 to 12 yr (N=176). Children and their parents were interviewed about the frequency, content, origins, coping behaviors and severity of children's nighttime fears. Results showed that 73.3% of the children reported nighttime fears, indicating that these fears are quite prevalent. Inspection of the developmental course of nighttime fears revealed that these fears are common among 4- to 6-year-olds, become even more frequent in 7- to 9-year-olds and then remain relatively stable in 10- to 12-year-olds. Inspection of the origins of nighttime fears revealed that most of the children (i.e., almost 80%) attributed their fear to negative information; conditioning and modeling were endorsed less frequently (25.6% and 13.2%, respectively). A substantial percentage of the children (24.0%) indicated that learning experiences had not played a role in the acquisition of their nighttime fears. Children reported a variety of coping strategies in order to deal with their nighttime fears and generally rated these strategies as helpful in reducing anxiety. Furthermore, children's nighttime fears were associated with moderate levels of anxiety. Moreover, in about 10% of the children, nighttime fears were related to one or more DSM-III-R anxiety disorders. Finally, parental reports of children's nighttime fears substantially deviated from children's reports. Most importantly, parents provided a marked underestimation of the frequency of nighttime fears, at least as reported by their children.