Reducing contrast makes speeds in a video-based driving simulator harder to discriminate as well as making them appear slower

We investigated the effect of reducing image contrast on speed perception using a video-based driving simulator in which participants viewed pairs of scenes and were asked to judge whether the second scene was faster or slower than the first scene. We predicted two outcomes: (i) that vehicle speeds would become harder to discriminate, and (ii) that vehicle speeds would appear slower. There is previous evidence confirming the latter prediction in a less realistic computer-based driving simulation, but none demonstrating the former. Our results supported both predictions, each of which may have traffic-safety implications when reduced-contrast conditions are experienced in real life, such as with fog or when the driver has cataracts.     

What is the reference in reference repulsion?

Reference repulsion is a mechanism posited to explain systematic biases of direction judgment of single drifting dot displays (Rauber and Treue, 1998 Perception 27 393-402). Rauber and Treue obtained systematic but, surprisingly, very different effects depending upon whether standard and comparison stimuli were presented simultaneously or successively. Successive effects were described as exhibiting repulsion from both vertical and horizontal cardinal axes, whereas simultaneous effects showed repulsion from horizontal only. We contend that the proposed mechanism makes no testable predictions because the so-called reference can only be specified a posteriori, a fact acknowledged by Rauber and Treue. We attempted to replicate Rauber and Treue's experiments, but we obtained no systematic biases of direction judgment. Comparisons across several studies suggest that errors in direction judgments of single drifting dot patterns vary widely in magnitude and direction, as might be expected with what are essentially baseline or pretest measures. In our view, reference repulsion describes neither a real perceptual mechanism nor a predictable pattern of direction misjudgments.     

The effect of comparative context upon stereotype content: children's judgments of ingroup behavior

This study addresses self-categorization theory's contention that stereotype content varies as a function of the comparative context within which a given group is considered. A sample of 5-, 7- and 10-year-old children (n = 192) made judgments about gender ingroup behavior in one of two comparative contexts: either adults of the same sex as self or children of the opposite sex. Specifically, judgments were either of the perceived stereotypicality or central tendency of 12 types of behavior. Both types of judgment were found to differ as a function of comparative context in ways predicted by self-categorization theory. However, contrary to prediction, there was no effect of age on the extent of stereotype variability.     

SAMPLES AS SYMBOLS

Nelson Goodman and, following him, Catherine Z. Elgin and Keith Lehrer have claimed that sometimes a sample is a symbol that stands for the property it is a sample of. The relation between the sample and the property it stands for is called ‘exemplification’ (Goodman, Elgin) or ‘exemplarisation’ (Lehrer). Goodman and Lehrer argue that the notion of exemplification sheds light on central problems in aesthetics and the philosophy of mind. However, while there seems to be a phenomenon to be captured, Goodman's account of exemplification has several flaws. In this paper I will offer an alternative account of exemplification that is inspired by Grice's idea that one can communicate something by providing one's audience with intention‐independent evidence and letting them draw the obvious conclusion for themselves. This explication of exemplification will solve the problems that arose for Goodman's theory in the spirit of his approach. 1     

Cosmic inflation and the past hypothesis

The past hypothesis is that the entropy of the universe was very low in the distant past. It is put forward to explain the entropic arrow of time but it has been suggested (e.g. [Penrose, R. (1989a). The emperor’s new mind. London:Vintage Books; Penrose, R. (1989b). Annals of the New York Academy of Sciences, 571, 249–264; Price, H. (1995). In S. F. Savitt (Ed.), Times’s arrows today. Cambridge: Cambridge University Press; Price, H. (1996). Time’s arrow and Archimedes’ point. Oxford: Oxford University Press; Price, H. (2004). In C. Hitchcock (Ed.), Contemporary debates in philosophy of science. Oxford: Blackwell]) that it is itself in need of explanation. It has also been suggested that cosmic inflation could provide the explanation, but Price (2004) raises a serious objection to this suggestion, which has otherwise received very little attention in the philosophical literature. Price points out that the standard inflationary explanation involves a double standard: although the evolution of the universe described by the inflationary model seems natural from the standard temporal perspective it looks highly unnatural from the reversed temporal perspective. The main purpose of this paper is to propose a novel form of the inflationary explanation that avoids this objection. It is argued that the inflationary model would not involve a double standard (but would still explain the past hypothesis) if we construct the model with a global “boundary” condition instead of a conventional boundary condition: if we assume that the universe is as generic as possible overall, rather than as generic as possible at some given point (e.g. the Big Bang) as is assumed in the standard inflationary model. This novel form of the inflationary explanation is then compared with Price’s 1996 preferred explanation, a version of the so-called “Weyl hypothesis”.     

Our Relations with the Past

The approach that philosophers have taken to history has too often been one-dimensional. It is my aim in this paper to map out a future multi-dimensional philosophy of history, by invoking the notion of a relation with the past, and by arguing for the philosophical relevance of multiple such relations.

A Longitudinal Analysis of Psychiatric Severity upon Outcomes Among Substance Abusers Residing in Self-Help Settings

A longitudinal analysis of psychiatric severity was conducted with a national sample of recovering substance abusers living in Oxford Houses, which are self-run, self-help settings. Outcomes related to residents' psychiatric severity were examined at three follow-up intervals over one year. Over time, Oxford House residents with high versus low baseline psychiatric severity reported significantly more days using psychiatric medication, decreased outpatient psychiatric treatment, yet no significant differences for number of days abstinent and time living in an Oxford House. These findings suggest that a high level of psychiatric severity is not an impediment to residing in self-run, self-help settings such as Oxford House among persons with psychiatric comorbid substance use disorders.     

What Motivates People to Participate More in Community‐based Coalitions?

The purpose of this study was to identify potential opportunities for improving member participation in community-based coalitions. We hypothesized that opportunities for influence and process competence would each foster higher levels of individual member participation. We tested these hypotheses in a sample of 818 members within 79 youth-oriented coalitions. Opportunities for influence were measured as members' perceptions of an inclusive board leadership style and members' reported committee roles. Coalition process competence was measured through member perceptions of strategic board directedness and meeting effectiveness. Members reported three types of participation within meetings as well as how much time they devoted to coalition business beyond meetings. Generalized linear models accommodated clustering of individuals within coalitions. Opportunities for influence were associated with individuals' participation both within and beyond meetings. Coalition process competence was not associated with participation. These results suggest that leadership inclusivity rather than process competence may best facilitate member participation.     

ADHD and Behavioral Inhibition: A Re-examination of the Stop-signal Task

The current study investigates two recently identified threats to the construct validity of behavioral inhibition as a core deficit of attention-deficit/hyperactivity disorder (ADHD) based on the stop-signal task: calculation of mean reaction time from go-trials presented adjacent to intermittent stop-trials, and non-reporting of the stop-signal delay metric. Children with ADHD (n = 12) and typically developing (TD) children (n = 11) were administered the standard stop-signal task and three variant stop-signal conditions. These included a no-tone condition administered without the presentation of an auditory tone; an ignore-tone condition that presented a neutral (i.e., not associated with stopping) auditory tone; and a second ignore-tone condition that presented a neutral auditory tone after the tone had been previously paired with stopping. Children with ADHD exhibited significantly slower and more variable reaction times to go-stimuli, and slower stop-signal reaction times relative to TD controls. Stop-signal delay was not significantly different between groups, and both groups’ go-trial reaction times slowed following meaningful tones. Collectively, these findings corroborate recent meta-analyses and indicate that previous findings of stop-signal performance deficits in ADHD reflect slower and more variable responding to visually presented stimuli and concurrent processing of a second stimulus, rather than deficits of motor behavioral inhibition.     

Response Style Differences in the Inattentive and Combined Subtypes of Attention-Deficit/Hyperactivity Disorder

This study examined potential differences between the inattentive and combined ADHD subtypes using laboratory tasks assessing behavioral inhibitory processes. Seventy-five children completed two tasks of behavioral inhibition believed to isolate different processes: the cued reaction time task (CRT), a basic inhibition task, and the go/no-go task (GNG), a complex inhibition task that incorporates motivational contingencies. Three groups of participants were identified, including ADHD/Inattentive (n = 17), ADHD/Combined (n = 37), and comparison (n = 21). Results indicated that rather than showing behavioral inhibition deficits, the ADHD/I children appeared overly inhibited, as evidenced by slower reaction times across the two tasks and significantly higher errors of omission in the GNG task. Additionally, the ADHD/I children did not demonstrate cue dependency effects on the CRT task, suggesting that they were failing to incorporate relevant information before making a response. The sluggish and inhibited performance of the ADHD/I group challenges the idea that it is a subtype of ADHD.