Facilitating paper recycling: effects of prompts, raffles, and contests

The effects of prompts and reinforcement to promote paper recycling were compared in six university dormitories. For a Prompt condition, residents were urged to recycle paper for ecological reasons via flyers distributed to each room. For a Raffle contingency, residents were given one raffle ticket for every pound of paper brought to a collection center. For a Contest contingency, two dorms were paired and the dorm whose residents delivered the most paper won $15 for its treasury. Contingency awareness was strengthened via a flyer placed under the door of each resident's room. Flyers alone had little effect in increasing paper-recycling behaviors, but the raffle (substantially) and the contest (somewhat) increased the amount of paper brought to a dorm's recycling center. Students whose rooms were closest to the collection center showed the greatest participation. Removal of the reinforcement contingencies resulted in a return to baseline levels.     

Human and machine perception of biological motion

More than 30 years ago, Johansson was the first to show that humans are capable of recovering information about the identity and activity of animate creatures rapidly and reliably from very sparse visual inputs – the phenomenon of biological motion. He filmed human actors in a dark setting with just a few strategic points on the body marked by lights – so-called moving light displays (MLDs). Subjects viewing the MLDs reported a vivid impression of moving human forms, and were even able to tell the activity in which the perceived humans were engaged. Subsequently, the phenomenon has been widely studied and many attempts have been made to model and to understand it. Typical questions that arise are: How precisely is the sparse low-level information integrated over space and time to produce the global percept, and how important is world knowledge (e.g., about animal form, locomotion, gravity, etc.)? In an attempt to answer such questions, we have implemented a machine-perception model of biological motion. If the computational model can replicate human data then it might offer clues as to how humans achieve the task. In particular, if it can do so with no or minimal world knowledge then this knowledge cannot be essential to the perception of biological motion. To provide human data for training and against which to assess the model, an extensive psychophysical experiment was undertaken in which 93 subjects were shown 12 categories of MLDs (e.g., normal, walking backwards, inverted, random dots, etc.) and were asked to indicate the presence or absence of natural human motion. Machine perception models were then trained on normal sequences as positive data and random sequences as negative data. Two models were used: a k-nearest neighbour (k-NN) classifier as an exemplar of ‘lazy’ learning and a back-propagation neural network as an exemplar of ‘eager’ learning. We find that the k-NN classifier is better able to model the human data but it still fails to represent aspects of knowledge about body shape (especially how relative joint positions change under rotation) that appear to be important to human judgements.     

Who shapes the self of independents and interdependents? Explicit and implicit measures of the self's relatedness to family,friends and partner

We suggest that social relationships shape the self in different ways, depending on whether persons define themselves as independent or interdependent. While the self of independents is most strongly associated with mental representations of others to whom they are related because of their own deliberate action (e.g. friends), the self of interdependents is most strongly connected with representations of others with whom they share allocated group memberships (e.g. family members). We took both explicit (Study 1) and implicit measures (Studies 2, 3 and 4) on how strongly independent and interdependent selves are associated with self‐chosen versus allocated close others. In Studies 3 and 4, we additionally primed the independent or interdependent self. Both explicit and implicit measures indicated that mental representations of family members were more strongly associated with the interdependent self than with the independent self, while romantic partners and friends were connected with both the independent and interdependent self. Copyright © 2006 John Wiley & Sons, Ltd.     

Repetition effects for words and nonwords as indexed by event-related fMRI: a preliminary study

We have previously shown differential effects of stimulus familiarity on the repetition-related responses in right fusiform cortex to both faces and symbols. Repetition of familiar stimuli produced a response decrease, whereas repetition of unfamiliar stimuli produced a response increase. In the present experiment, we used words and nonwords as the familiar and unfamiliar stimuli respectively. In this case, the only fusiform region showing the familiarity-by-repetition interaction was in anterior left fusiform. This left-lateralisation of the fusiform interaction is consistent with our hypothesis that these repetition-related effects occur in the same regions responsible for perceptual recognition of familiar stimuli.     

Person perception when aggressive or nonaggressive sports are primed

Previous research investigating the factors contributing to sports spectator violence has focused primarily on conscious processes such as the disinhibiting effects of aggressive models and physiological arousal. The current research borrows a methodology from social cognition work to examine the role of passive, category accessibility effects on fan hostility. Prior research has indicated that as a schema becomes more accessible in memory, the use of it to encode subsequent information is increased. It was therefore hypothesized that individuals for whom the category of hostility had been unobtrusively primed with aggressive-sports names (e.g., boxing) would rate an ambiguous target person as more hostile and as more likely to prefer hostile activities relative to persons who were primed with sports names which were not associated with violence (e.g., golf). The results supported the hypotheses, with subjects who were primed with aggressive-sports rating an unrelated target person's behavior as significantly more hostile and as more likely to prefer aggressive activities relative to subjects exposed to sentences containing references to nonaggressive-sports. Discussion includes the potential ramifications for spectator aggression at sporting events.     

Affect in the eyes: explicit and implicit evaluations

The present study investigated whether another individual’s gaze direction influences an observer’s affective responses. In Experiment 1, subjective self-ratings and an affective priming paradigm were employed to examine how participants explicitly and implicitly, respectively, evaluated the affective valence of direct gaze, averted gaze, and closed eyes. The explicit self-ratings showed that participants evaluated closed eyes more positively than direct gaze. However, the implicit priming task showed an inverse pattern of results indicating that direct gaze was automatically evaluated more positively than closed eyes were. Experiment 2 confirmed that the opposite patterns of results between the two tasks were not due to differences in presentation times of the gaze stimuli. The results provide evidence for automatic affective reactions to eye gaze and indicate a dissociation between explicit and implicit affective evaluations of eyes and gaze direction.