The definability of objective becoming in Minkowski spacetime

In his recent article On Relativity Theory and Openness of the Future (1991), Howard Stein proves not only that one can define an objective becoming relation in Minkowski spacetime, but that there is only one possible definition available if one accepts certain natural assumptions about what it is for becoming to occur and for it to be objective. Stein uses the definition supplied by his proof to refute an argument due to Rietdijk (1966, 1976), Putnam (1967) and Maxwell (1985, 1988) that Minkowski spacetime leaves no room for objective becoming whatsoever. However, Stein's proof does not seem to go far enough. By considering only what events have become from the standpoint of any given event, Stein's uniqueness proof fails from the outset to allow for a more general kind of becoming whereby it is understood to occur from the standpoint of events on the particular worldlines followed by observers. This suggests that there may, after all, be more than one way to define objective becoming in Minkowski spacetime once each observer's worldline is allowed to figure in the definition. This suspicion is further aroused by two recent proposals for objective, worldline-dependent becoming due to Peacock (1992) and Muller (1992) who advocate ways of defining becoming that are not equivalent to the definition Stein's uniqueness proof delivers. Nevertheless, we show that Stein's uniqueness proofcan be extended in a natural way to cover this more general kind of becoming, provided one does not enrich standard Minkowski spacetime by privileging certain sets of worldlines over others in an unwarranted manner. Thus we aim to reinforce Stein's point that standard Minkowski spacetime does make room for objective becoming, but in essentially only one way, despite arguments and proposals to the contrary.     

Coping with intractable controversies: The case for problem structuring in policy design and analysis

Intractable controversies and other types of policy disagreements correspond to policy problems with a different structure. The more structured a problem is, the more consensus there is about which values and information are at stake in the process of problem solving. Policymakers like to treat problems in as structured a way as possible. Three policy strategies are described to move away from the unstructured to the more structured problem type. However, policymakers run the risk of oversimplifying an ill-structured problem, which means that elements of the problem situation relevant to other actors are overlooked or denied. Hence, policy controversies may become intractable. The remedy is a fourth strategy, characterised by problem structuring. This strategy requires political participation of actors with different views on the problem, and an argued political problem choice. His main research areas are problem structuring in public policy, knowledge use, environmental risk, technology and democracy. He is currently working on knowledge-based policy strategies for addressing the issue of climate change. His research interest is to develop and apply discursive and/or argumentative approaches to the policy process.     

Cross-informant consistency in externalizing and internalizing problems in early adolescence

The concept of cross-informant consistency has long been a topic of interest for those involved in assessment of behavior problems in adolescence. The purpose of the present study was to replicate and expand the existing literature by including four informants (mother, father, teacher, and adolescent self-report) and examining correlations among them as well as differences between reporters on an absolute level of both internalizing and externalizing problems. Fifty-two young adolescents (ranging in age from 11 to 15 years) and their mothers, fathers, and social studies teachers participated in the study. The Conduct Disorder subscale, Socialized Aggression subscale, and Anxiety/Withdrawal subscale of the Revised Behavior Problem Checklist were used. Results indicated that teachers showed little agreement with other informants on conduct problems (teachers reporting fewer problems), while parents and adolescents showed significant agreement. Informants showed no agreement on the measure of covert problems (socialized aggression), and all reports showed agreement on internalizing problems (although teachers continued to report fewer problems). Implications for assessment of young adolescents are discussed.This research was supported, in part, by the William T. Grant Foundation and the University of Georgia's Institute for Behavior Research.     

Software tools for creating line drawings on a CRT

A software package that can be used for the generation of line drawings on CRTs is discussed. The pictures obtained are stored as sets of coordinates of line segments. Complex pictures consist of sets of subpictures. In this way, pictures, or parts of pictures, can be easily manipulated (e.g., rotated, translated, scaled) and can be displayed on different types of display systems.     

Psychological Responses to the Threat of Nuclear War

We investigated the nature of psychological responses to the threat of nuclear war and the relationships between attitudes and behavior in three studies. The first was a quasi-experimental study of the effects of a film depiction of nuclear war on attitudes and behavior. Results suggested that exposure was mediated by a sense of control over political events, but that exposure itself had no significant effect on psychological responses to nuclear war. The second was an experimental investigation of the effects of efficacy enhancing, fear arousing, or informational tactics as well as individual differences on memory for relevant information and political activism on the issue of nuclear arms control. Results indicated that men exposed to the fear arousal tactic were less likely to take action than those exposed to information alone or efficacy enhancement, whereas women exposed to fear arousal were more likely to act. Gender differences are explained in terms of the socialization of male responses to fear, the "macho" response. Those who showed less denial were more likely to act, as were those who stated intentions to take action. The third study employed structural modeling to examine the relationships between attitudes and behavior. Results supported the Model of Reasoned Action (Fishbein & Ajzen, 1975) in showing that intentions to act mediated the relationship between attitudes and behavior on this issue.     

A comparison of 13-year-old boys with attention deficit and/or reading disorder on neuropsychological measures

This study compared 13 year-old-boys with attention deficit disorder (ADD) and/or reading disability (RD), and controls with neither disorder on a battery of verbal and nonverbal neuropsychological measures. The aim was to examine whether ADD was associated with a qualitatively distinct pattern of deficits compared with RD. None of the measures differentiated the boys with ADD-only from the controls; the only deficit associated with ADD was slightly lower IQ. RD, on the other hand, was associated with deficits in memory and verbal skills.The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council of New Zealand and involves several Departments of the University of Otago. Much of the data are gathered by voluntary workers from the Dunedin community.The authors are indebted to the many people who contributions make this ongoing study possible. We wish to acknowledge the advice and help of Dr. P. A. Silva, director of the Dunedin Unit, in preparing this report.     

The structure and correlates of self-reported symptoms in 11-year-old children

Self-reports of DSM-III symptomatology were obtained from 792 11-year-old children using the Diagnostic Interview Schedule for Children (DISC). We report results concerning 13 subscales derived from the DISC. Factor-analysis of the subscales suggested a broad distinction between externalizing and internalizing disorder for boys' self-report. For girls, two separate internalizing factors representing anxiety and depression emerged. We also found sex differences in correlates of self-reported disorder. Finally, we examined agreement between child and parent and teacher reports. Overall, agreement was relatively low, although somewhat higher for child-parent than for child-teacher.The Dunedin Multidisciplinary Health and Development Research Unit is supported by the Medical Research Council of New Zealand and the Departments of Education and Health, and involves several departments of the University of Otago. Much of the data are gathered by voluntary workers from the Dunedin community. The authors are indebted to the many people whose contributions make this ongoing study possible.     

Semantic activation during recognition of referential words

Summary This paper represents a contribution to the study of the processes of semantic activation during the recognition of referential words, that is, common nouns used to denote real objects. The two experiments reported in the present study have attempted to test the hypothesis of a differential rate of activation of two components of the semantic information activated when a word is presented. These components consist of a perceptually based component and a nonperceptual, more abstract one. The present study has shown that the two components are likely to be activated at different rates. Perceptually based semantic information, probably acquired earlier in the process of the acquisition of word's meaning, seems to be available earlier or with a faster maximum activation effectiveness than information based on abstract or functional properties of the objects to which the words refer.     

Effects of visual-field and matching instruction on event-related potentials and reaction time

Vertical letter pairs were presented randomly in the left and right visual hemifields in a physical identity match and name identity match condition. The reaction times showed a right visual field superiority for name matches, and a left visual field superiority for physical matches. Event-related potentials to letter pairs showed a sequence of three waves: a negative wave (N2, around 270 msec), a positive wave (P3, around 500 msec), and a broad positive slow wave (SW, around 600-700 msec), respectively. P3 and SW amplitudes were consistently larger at the left hemisphere than at the right hemisphere, regardless of the field of stimulation. At both hemispheres, N2 waves were always larger to stimuli presented in the visual field contralateral to a hemisphere than stimuli presented in the visual field ipsilateral to a hemisphere. The positive waves (P3, SW) showed the opposite pattern: smaller amplitudes to stimuli that were presented contralaterally than stimuli that were presented ipsilaterally to a given hemisphere. These results were attributed to a shift in sustained negativity on the directly stimulated hemisphere, relative to the indirectly stimulated hemisphere, reflecting either sensory at attentional processes in the posterior cerebral hemispheres.     

The Sound of Grasp Affordances: Influence of Grasp‐Related Size of Categorized Objects on Vocalization

Previous research shows that simultaneously executed grasp and vocalization responses are faster when the precision grip is performed with the vowel [i] and the power grip is performed with the vowel [ɑ]. Research also shows that observing an object that is graspable with a precision or power grip can activate the grip congruent with the object. Given the connection between vowel articulation and grasping, this study explores whether grasp‐related size of observed objects can influence not only grasp responses but also vowel pronunciation. The participants had to categorize small and large objects into natural and manufactured categories by pronouncing the vowel [i] or [ɑ]. As predicted, [i] was produced faster when the object's grasp‐related size was congruent with the precision grip while [ɑ] was produced faster when the size was congruent with the power grip (Experiment 1). The effect was not, however, observed when the participants were presented with large objects that are not typically grasped by the power grip (Experiment 2). This study demonstrates that vowel production is systematically influenced by grasp‐related size of a viewed object, supporting the account that sensory‐motor processes related to grasp planning and representing grasp‐related properties of viewed objects interact with articulation processes. The paper discusses these findings in the context of size–sound symbolism, suggesting that mechanisms that transform size‐grasp affordances into corresponding grasp‐ and articulation‐related motor programs might provide a neural basis for size‐sound phenomena that links small objects with closed‐front vowels and large objects with open‐back vowels.