The facing bias in biological motion perception: structure, kinematics, and body parts

Depth-ambiguous point-light walkers (PLWs) elicit a facing bias: Observers perceive a PLW as facing toward them more often than as facing away (Vanrie,Dekeyser, & Verfaillie, Perception, 33, 547-560, 2004). While the facing bias correlates with the PLW's perceived gender (Brooks et al., Current Biology, 18, R728-R729, 2008; Schouten, Troje, Brooks, van der Zwan, & Verfaillie, Attention, Perception, & Psychophysics, 72,1256-1260, 2010), it remains unclear whether the change in perceived in-depth orientation is caused by a change in perceived gender. In Experiment 1, we show that structural and kinematic stimulus properties that lead to the same changes in perceived gender elicit opposite changes in perceived in-depth orientation, indicating that the relation between perceived gender and in-depth orientation is not causal. The results of Experiments 2 and 3 further suggest that the perceived in-depth orientation of PLWs is strongly affected by locally acting stimulus properties. The facing bias seems to be induced by stimulus properties in the lower part of the PLW.     

Effects of endorphin blocking on conditioned SCR in humans

In order to test the hypothesis that low levels of endogenous opioids (endorphins) predispose to strong conditioning effects, female Ss (N = 36) were assigned to a placebo group, a low-dose naltrexone group, or a high-dose naltrexone group and then underwent a classical conditioning procedure. This procedure consisted of an acquisition phase in which all Ss received 5 pairings of a CS+ (neutral picture) and a UCS (100 dB white noise). The CS− (neutral picture) was never followed by a UCS. During extinction, Ss received 4 unreinforced presentations of CS+ and CS−. Throughout the experiment, skin conductance responses (SCRs) to the CSs and UCSs were recorded. Acquisition was successful in that CS+ slides elicited stronger SCRs than CS − slides. However, during acquisition, there was no interaction between drug and differential response (CS+ vs CS−). During extinction, there was no overall remaining effect of conditioning. Again, no evidence was found to suggest that (remaining) effects of conditioning were stronger in the naltrexone treated Ss than in the placebo S's. If anything, the opposite seemed to be true with especially high-dose naltrexone Ss showing relatively weak conditioning effects.     

Can We Use Social Policy to Enhance Compliance with Moral Obligations to Animals?

Those who wish to abolish or restrict the use of non-human animals in so-called factory farming and/or experimentation often argue that these animal use practices are incommensurate with animals’ moral status. If sound, these arguments would establish that, as a matter of ethics or justice, we should voluntarily abstain from the immoral animal use practices in question. But these arguments can’t and shouldn’t be taken to establish a related conclusion: that the moral status of animals justifies political intervention to disallow or significantly diminish factory farming and animal experimentation. In this paper, we set out to do two things: First, we argue that while the arguments mentioned above may establish the moral impermissibility or injustice of the practices they condemn, they are not sufficient to justify political interventions or social policies to abolish or restrict such practices. It is one thing to argue that some moral imperative or imperative of justice exists, and quite another thing to call for the use of political power to induce compliance with that imperative. Our second task is to assess the prospects for developing an argument that is sufficient to justify political interventions to restrict or abolish the use of non-human animals in factory farming or experimentation. Beyond establishing the immorality or injustice of animal consumption or experimentation, one must show that the interventions in question constitute legitimate use of political power. Would prohibiting or discouraging animal use be legitimate? We attempt to answer this question within the context of fundamental liberal constraints on the legitimate use of coercive political power.     

Pathways to fear in spider phobic children

Twenty-two children with spider phobia were interviewed about the origins of their fear. More specifically, children were asked about conditioning events, modeling experiences, and negative information transmission. To evaluate the reliability of the information provided by the children, parents were independently interviewed about the origins of their children's phobias. While 46% of the children claimed to have always been afraid, 41% ascribed the onset of their fear to aversive conditioning events. The large majority of these events were confirmed by parents. These findings cast doubts on a strong version of the non-associative account of spider phobia, i.e. the idea that spider phobia is acquired in the complete absence of learning experiences.     

Philosophy in Schools: Can Early Exposure Help Solve Philosophy's Gender Problem?

In this article, I explore a new reason in favor of precollegiate philosophy: It could help narrow the persistent gender disparity within the discipline. I catalog some of the most widely endorsed explanations for the underrepresentation of women in philosophy and argue that, on each hypothesized explanation, precollegiate philosophy instruction could help improve our discipline's gender balance. Explanations I consider include stereotype threat, gendered philosophical intuitions, inhospitable disciplinary environment, lack of same‐sex role models for women students in philosophy, and conflicting “schemas” for philosophy and femininity. I argue that, insofar as some combination of these hypothesized explanations accounts for some portion of the underrepresentation of women in philosophy, those of us concerned to make things better have reason to participate in and promote efforts to share philosophy with younger students.     

Developing a model of adolescent friendship formation on the internet.

Previous research has been largely silent about what precisely influences online friendship formation and has ignored motives for online communication as potential explanations. Drawing on a sample of 493 adolescents, this study tested a path model of adolescent friendship formation including as predictors introversion/extraversion, online self-disclosure, motive for social compensation, and frequency of online communication. Our path analysis showed that extraverted adolescents self-disclosed and communicated online more frequently, which, in turn, facilitated the formation of online friendships. Introverted adolescents, by contrast, were more strongly motivated to communicate online to compensate for lacking social skills. This increased their chances of making friends online. Among introverted adolescents, a stronger motive for social compensation also led to more frequent online communication and online self-disclosure, resulting in more online friendships. The model suggests that the antecedents of online friendship formation are more complex than previously assumed and that motives for online communication should be studied more closely.     

Characteristics and motives of adolescents talking with strangers on the internet.

Despite widespread concerns about the dangers of adolescents' online communication with strangers, we know little about (a) which types of adolescents talk with strangers and (b) what motivates them to do so. Drawing on a survey among 412 Dutch adolescents, we found that early adolescents (12-14-year-olds) were most prone to talk with strangers on the internet. If adolescents communicated online more frequently, they less often talked with strangers on the internet. However, if adolescents engaged in long chat sessions, they tended to talk with strangers on the internet more often. In contrast to earlier research, introversion was not related to adolescents' tendency to talk with strangers. The motives of entertainment, meeting new people, and social compensation increased adolescents' online communication with strangers.     

Inferring intentions from biological motion: A stimulus set of point-light communicative interactions

We present the first database of communicative interactions reproduced through point-light displays (Communicative Interaction Database). The database contains 20 communicative interactions performed by male and by female couples. For each action, we provide movie files from four different viewpoints, as well as text files with the 3-D spatial coordinates of the point lights, allowing researchers to construct customized versions. By including various types of actions performed with different social motives, the database contains a diverse sample of nonconventional communicative gestures. Normative data collected to assess the recognizability of the stimuli suggest that, for most action stimuli, information in point-light displays is sufficient for clear recognition of the action as communicative, as well as for identification of the specific communicative gesture performed by the actor. The full set of stimuli may be downloaded from http://brm.psychonomic-journals.org/ content/supplemental and from http://ppw.kuleuven.be/labexppsy/lepSite/resources/CID.rar.     

Friend networking sites and their relationship to adolescents' well-being and social self-esteem.

The aim of this study was to investigate the consequences of friend networking sites (e.g., Friendster, MySpace) for adolescents' self-esteem and well-being. We conducted a survey among 881 adolescents (10-19-year-olds) who had an online profile on a Dutch friend networking site. Using structural equation modeling, we found that the frequency with which adolescents used the site had an indirect effect on their social self-esteem and well-being. The use of the friend networking site stimulated the number of relationships formed on the site, the frequency with which adolescents received feedback on their profiles, and the tone (i.e., positive vs. negative) of this feedback. Positive feedback on the profiles enhanced adolescents' social self-esteem and well-being, whereas negative feedback decreased their self-esteem and well-being.