Head-mounted displays for clinical virtual reality applications: pitfalls in understanding user behavior while using technology.

The use of virtual environments with head-mounted displays (HMDs) offers unique assets to the evaluation and therapy of clinical populations. However, research examining the effects of this technology on clinical populations is sparse. Understanding how wearers interact with the HMD is vital. Discomfort leads to altered use of the HMD that could confound performance measures; the very measures which might be used as tools for clinical decision making. The current study is a post-hoc analysis of the relationship between HMD use and HMD comfort. The analysis was conducted to examine contributing factors for a high incidence of simulator sickness observed in an HMD-based driving simulator. Pearson correlation analysis was used to evaluate objective and subjective measures of HMD performance and self-reported user comfort ratings. The results indicated weak correlations between these variables, indicating the complexity of quantifying user discomfort and HMD performance. Comparison of two case studies detailing user behavior in the virtual environment demonstrates that selected variables may not capture how individuals use the HMD. The validity and usefulness of the HMD-based virtual environments must be understood to fully reap the benefits of virtual reality (VR) in rehabilitation medicine.     

Primacy, recency, and suffix effects in auditory short-term memory for pure tones: evidence from a probe recognition paradigm.

The present study was designed to explore serial position and suffix effects in the short-term retention of nonverbal sounds. In contrast with previous studies of these effects, a probe recognition paradigm was used to minimize the possibility that participants would use a verbal labelling strategy. On each trial, participants heard a memory set consisting of three pure tones, followed five seconds later by a probe tone. Participants were required to indicate whether or not the probe tone had been a member of the memory set. On most trials, a suffix sound was presented 1 second following the third sound in the memory set. Results revealed that tones presented in the first and last positions of the memory set were recognized more accurately than were tones presented in the middle position. Furthermore, recognition of sounds presented in the last position was compromised when the memory set was followed by a postlist suffix of similar pitch, spectral composition, and spatial location.     

How many fingers am I holding up? The answer depends on children's language background

Monolingual English‐speaking preschool children tend to process number gestures as unanalyzed wholes rather than use the one‐to‐one (finger‐to‐quantity) correspondence. By school age, however, children can use the one‐to‐one correspondence. The purpose of the present studies was to test whether children learn one‐to‐one correspondence through exposure to a variety of finger configurations to convey a single quantity. In Study 1, we compared children with exposure to multiple one‐to‐one configurations, that is, French‐English and German‐English bilingual children, to English monolingual children who see consistent representations. As predicted, the bilingual children performed better in interpreting unconventional number gestures. In Study 2, we compared Chinese‐English bilingual children who knew arbitrary one‐handed Chinese numbers gestures for quantities 6–10 to Chinese‐English bilingual children who did not know these gestures, as well as to monolingual English speakers. Chinese‐English bilinguals who knew the arbitrary gestures were more likely to interpret unconventional gestures arbitrarily (i.e., influenced by the written and/or Chinese gesture forms). These children did not differ from English monolinguals in the interpretation of unconventional gestures. These results are consistent with the argument that children can become sensitive to the one‐to‐one correspondence in number gestures with exposure to multiple configurations for the same quantity.     

Development of prospective memory: tasks based on the prefrontal-lobe model.

This study investigated the development of prospective memory using tasks based on the prefrontal-lobe model. Three groups each of 30 children, adolescents, and young adults were compared on prospective-memory performance using ongoing tasks with two levels of cognitive demand (low and high), and two levels of importance (unstressed and stressed) of remembering prospective cues. The Self-Ordered Pointing Task (SOPT), Stroop Color Word Interference Test, and Tower of London were also used to assess relationships between prospective memory and prefrontal-lobe functions. The children remembered fewer prospective cues than either the adolescents or adults, but the adolescents and adults remembered equally well. This trend increased significantly as the cognitive demand of the ongoing tasks increased. However, stressing or not stressing the importance of remembering made no difference to prospective-memory performance. Performance on the SOPT and Stroop Colour Word Interference predicted performance on the high- but not on the low-demand condition. These findings implicate the maturation of the brain's prefrontal region in the development of prospective memory.     

John Nash: The Sufferings of Those Who Loved Him

This article, as a sequel to three previous papers on John Nash by Capps (2003, 2004a, & 2004b), focuses on the other side of Nashs beautiful mind by examining the sufferings of those who loved him. Nashs mistress and wife, appear to have suffered the most by Nashs narcissistic and paranoid schizophrenic tendencies due to his noncommittal and disrespectful attitudes. Nashs exploitive and experiential ways of relating to his close male friends (special friendships) seemed to have caused much pain and agony in at least two of his special friends. In addition, Nashs two sons also suffered from his lack of affection and responsibility. Thus it is crucial for people in mental health professionals as well as in pastoral care and counseling not only to care for the mentally ill but also for those who are around him or her.     

Teaching ethics and technology with <Emphasis Type="Italic">Agora</Emphasis>, an electronic tool

Courses on ethics and technology have become compulsory for many students at the three Dutch technical universities during the past few years. During this time, teachers have faced a number of didactic problems, which are partly due to a growing number of students. In order to deal with these challenges, teachers in ethics at the three technical universities in the Netherlands — in Delft, Eindhoven and Twente — have developed a web-based computer program called Agora (see www.ethicsandtechnology.com). This program enables students to exercise their ethical understanding and skills extensively. The program makes it possible for students to participate actively in moral reflection and reasoning, and to develop the moral competencies that are needed in their later professional practice. The developers of the program have tried to avoid two traps. Firstly, they rejected, from the outset, a cookbook style of dealing with ethical problems that applied ethics is often taken to be and, secondly, they wanted to design a flexible program that respects the student’s as well as the teacher’s creativity, and that tries to engage students in moral reflection. Agora meets these requirements. The program offers possibilities that extend beyond the requirements that are usually accepted for case-exercises in applied ethics, and that have been realised in several other computer models for teaching ethics. In this article, we describe the main considerations in the development of Agora and the features of the resulting program.     

Understanding moral responsibility in the design of trailers

This paper starts from the presupposition that moral codes often do not suffice to make agents understand their moral responsibility. We will illustrate this statement with a concrete example of engineers who design a truck’s trailer and who do not think traffic safety is part of their responsibility. This opinion clashes with a common supposition that designers in fact should do all that is in their power to ensure safety in traffic. In our opinion this shows the need for a moral philosophy that helps engineers to interpret their responsibility and think more critically about it. For this purpose we will explore the moral philosophy of Alasdair MacIntyre, which is particularly interesting because he locates the beginning of moral thinking in the daily practice of a profession. This is consistent with the history of moral codes, for codes are also the product of moral reflection by professionals. We will use MacIntyre’s philosophy to (1) explain what is wrong with the designers’ understanding of their responsibility and (2) show a possible way to bring their reflection to a more self-critical level. We will also inspect MacIntyre’s proposal critically.     

Attachment dimensions as predictors of medical hospitalizations in individuals with DSM IV cluster B personality disorders

This study investigates predictors of health service utilization in individuals with cluster B personality disorders. We hypothesized an association of severity of psychopathology (that is, global psychosocial functioning and psychiatric comorbidity) and attachment style with the length of medical hospitalizations in this population. Forty-one female subjects were interviewed regarding their diagnoses, level of functioning and service utilization. Attachment style was assessed with a self-report questionnaire. Our findings indicate that degree of psychiatric comorbidity and level of psychosocial functioning do not predict length of hospital stays, whereas preoccupied attachment predicted 23.9% of the variance in the length of hospitalizations. We conclude that the quality of interpersonal relatedness appears to be a better predictor of health service use than severity of pathology in patients with cluster B personality disorders.     

The neuronal basis of bimanual coordination: recent neurophysiological evidence and functional models

Recent physiological studies of the neuronal processes underlying bimanual movements provide new tests for earlier functional models of bimanual coordination. The recently acquired data address three conceptual areas: the generalized motor program (GMP), intermanual crosstalk and dynamic systems models. To varying degrees, each of these concepts has aspects that can be reconciled with experimental evidence. The idea of a GMP is supported by the demonstration of abstract neuronal motor codes, e.g. bimanual-specific activity in motor cortex. The crosstalk model is consistent with the facts that hand-specific coding also exists and that interactions occur between the motor commands for each arm. Uncrossed efferent projections may underlie crosstalk on an executional level. Dynamic interhemispheric interactions through the corpus callosum may provide a high-level link at the parametric programming level, allowing flexible coupling and de-coupling. Flexible neuronal interactions could also underlie adaptive large-scale systems dynamics that can be formalized within the dynamic systems theory approach.

The correspondence of identified neuronal processes with functions of abstract models encourages the development of realistic computational models that can predict bimanual behavior on the basis of neuronal activity.