Do we perceive a flattened world on the monitor screen?

The current model of three-dimensional perception hypothesizes that the brain integrates the depth cues in a statistically optimal fashion through a weighted linear combination with weights proportional to the reliabilities obtained for each cue in isolation (Landy, Maloney, Johnston, & Young, 1995). Even though many investigations support such theoretical framework, some recent empirical findings are at odds with this view (e.g., Domini, Caudek, & Tassinari, 2006). Failures of linear cue integration have been attributed to cue-conflict and to unmodelled cues to flatness present in computer-generated displays. We describe two cue-combination experiments designed to test the integration of stereo and motion cues, in the presence of consistent or conflicting blur and accommodation information (i.e., when flatness cues are either absent, with physical stimuli, or present, with computer-generated displays). In both conditions, we replicated the results of Domini et al. (2006): The amount of perceived depth increased as more cues were available, also producing an over-estimation of depth in some conditions. These results can be explained by the Intrinsic Constraint model, but not by linear cue combination.     

Do infants have a sense of fairness?

Two experiments examined infants' expectations about how an experimenter should distribute resources and rewards to other individuals. In Experiment 1, 19-month-olds expected an experimenter to divide two items equally, as opposed to unequally, between two individuals. The infants held no particular expectation when the individuals were replaced with inanimate objects, or when the experimenter simply removed covers in front of the individuals to reveal the items (instead of distributing them). In Experiment 2, 21-month-olds expected an experimenter to give a reward to each of two individuals when both had worked to complete an assigned chore, but not when one of the individuals had done all the work while the other played. The infants held this expectation only when the experimenter could determine through visual inspection who had worked and who had not. Together, these results provide converging evidence that infants in the 2nd year of life already possess context-sensitive expectations relevant to fairness.     

Do infants show social preferences for people differing in race?

Do infants develop meaningful social preferences among novel individuals based on their social group membership? If so, do these social preferences depend on familiarity on any dimension, or on a more specific focus on particular kinds of categorical information? The present experiments use methods that have previously demonstrated infants’ social preferences based on language and accent, and test for infants’ and young children’s social preferences based on race. In Experiment 1, 10-month-old infants took toys equally from own- and other-race individuals. In Experiment 2, 2.5-year-old children gave toys equally to own- and other-race individuals. When shown the same stimuli in Experiment 3, 5-year-old children, in contrast, expressed explicit social preferences for own-race individuals. Social preferences based on race therefore emerge between 2.5 and 5 years of age and do not affect social choices in infancy. These data will be discussed in relation to prior research finding that infants’ social preferences do, however, rely on language: a useful predictor of group or coalition membership in both modern times and humans’ evolutionary past.     

Do 5-month-old infants see humans as material objects?

Infants expect objects to be solid and cohesive, and to move on continuous paths through space. In this study, we examine whether infants understand that human beings are material objects, subject to these same principles. We report that 5-month-old infants apply the constraint of continuous motion to inanimate blocks, but not to people. This suggests that young infants have two separate modes of construal: one for inanimate objects and another for humans.     

Do 9-month-olds perceive causation-at-a-distance?

Humans understand mechanical events to involve physical bodies interacting by contact, but intentional events involve agents that can also interact at a distance. We investigated infant sensitivity to causality in a simple event in which one agent appears to react to another without contact. Infants 9 months old were habituated to one of two events involving a computer-animated red square moving nonrigidly--like a caterpillar--towards a green square. In the 'reaction event', the green object moved in turn before the red one stopped, while in the 'pause event' the green object moved after the red one stopped. After habituation, each infant saw the habituation movie played in reverse. This test involved identical spatiotemporal changes for reaction and pause event, but the reversed reaction additionally involved a change in the causal roles. Infants dishabituated to reversal of the reaction but not the pause event, a result which suggests sensitivity to causation-at-a-distance. This ability could support development of social cognition and theory of mind.     

Do infants recognize the Arcimboldo images as faces? Behavioral and near-infrared spectroscopic study

Arcimboldo images induce the perception of faces when shown upright despite the fact that only nonfacial objects such as vegetables and fruits are painted. In the current study, we examined whether infants recognize a face in the Arcimboldo images by using the preferential looking technique and near-infrared spectroscopy (NIRS). In the first experiment, we measured looking preference between upright and inverted Arcimboldo images among 5- and 6-month-olds and 7- and 8-month-olds. We hypothesized that if infants perceive the Arcimboldo images as faces, they would prefer the upright images to the inverted ones. We found that only 7- and 8-month-olds significantly preferred upright images, suggesting that they could perceive the Arcimboldo images as faces. In the second experiment, we measured hemodynamic responses using NIRS. Based on the behavioral data, we hypothesized that 7- and 8-month-olds would show different neural activity for upright and inverted Arcimboldo images, as do adults. Therefore, we measured hemodynamic responses in 7- and 8-month-olds while they were looking at upright and inverted Arcimboldo images. Their responses were then compared with the baseline activation during the presentation of individual vegetables. We found that the concentration of oxyhemoglobin increased in the left temporal area during the presentation of the upright images compared with the baseline during the presentation of vegetables. The results of the two experiments suggest that (a) the ability to recognize the upright Arcimboldo images as faces develops at around 7 or 8 months of age and (b) processing of the upright Arcimboldo images is related to the left temporal area of the brain.     

Do blushing phobics overestimate the undesirable communicative effects of their blushing?

Previous research indicated that blushing has socially threatening revealing effects in ambiguous situations. To explain blushing phobics' fearful preoccupation with blushing, we tested the hypothesis that blushing fearful individuals overestimate its revealing effects. High (n = 20) and low (n = 20) blushing fearful individuals read vignettes describing prototypical mishaps and ambiguous social events. Participants were prompted in the perspective of the actor, and were asked to indicate their expectations of the observers' judgments (meta-perceptions). Blushing fearful individuals overestimated the probability and the costs of undesirable outcomes. However, this judgmental bias was not inflated by displaying a blush. Thus, the results provide no evidence to support the idea that fear of blushing is fuelled by a biased conception of its communicative effects.     

Do inexperienced bumblebee foragers use scent marks as social information?

Bumblebees (Bombus spp.) foraging in the field typically reject flowers where they detect the olfactory footprints of previous visitors and hence avoid recently emptied inflorescences. A growing number of studies have begun to illustrate that associative learning shapes the development of this process, in both bumblebees and other bee species. This raises the question of what the default response to such marks is, but little is known about how inexperienced foragers use social information. Here, we offered flower-naive bees a choice between scent-marked flowers and unmarked alternatives and found that individuals neither avoided nor preferred marked flowers. Our findings provide no support for ‘hard-wired’ responses to scent marks in bumblebees and highlight the importance of associative learning in shaping social information use to match local circumstances.     

Ethical social justice: Do the ends justify the means?

This article offers an ethical decision‐making model, informed by community psychology values, as a means for guiding psychologists when engaging in social justice‐oriented work. The applicability of this model is demonstrated through a case analysis elucidating how America's psychologists individually and collectively arrived at the decision to endorse torture—ostensibly as a means for preventing terrorism. Critics have wondered how the American Psychological Association succumbed to these involvements, and how to prevent such ethical lapses in the future. Unfortunately, the American Psychological Association's ethical codes fail to provide explicit guidance for psychologists' involvement in social justice work that impacts communities and systems. To address this gap, we present a values‐driven, ethical decision‐making framework that may be used to guide psychologists' future practices. This framework infuses fundamental community psychology values (i.e., caring and compassion; health; self‐determination and participation, human diversity, social justice; and critical reflexivity) into a 9‐step model.     

Do the young and the old perceive emotional intervals differently when shown on a younger or older face?

Cognitive Processing - Many authors have analysed the effects of emotion recognition on time perception, showing that the more arousing the stimuli are the greater is the effect on duration...     

Do facial first impressions reflect a shared social reality?

Influential facial impression models have repeatedly shown that trustworthiness, youthful–attractiveness, and dominance dimensions subserve a wide variety of first impressions formed from strangers’ faces, suggestive of a shared social reality. However, these models are built from impressions aggregated across observers. Critically, recent work has now shown substantial inter-observer differences in facial impressions, raising the important question of whether these dimensional models based on aggregated group data are meaningful at the individual observer level. We addressed this question with a novel case series approach, using factor analyses of ratings of twelve different traits to build individual models of facial impressions for different observers. Strikingly, three dimensions of trustworthiness, youthful/attractiveness, and competence/dominance appeared across the majority of these individual observer models, demonstrating that the dimensional approach is indeed meaningful at the individual level. Nonetheless, we also found differences in the stability of the competence/dominance dimension across observers. Taken together, results suggest that individual differences in impressions arise in the context of a largely common structure that supports a shared social reality.     

Do domestic dogs interpret pointing as a command?

Domestic dogs comprehend human gestural communication flexibly, particularly the pointing gesture. Here, we examine whether dogs interpret pointing informatively, that is, as simply providing information, or rather as a command, for example, ordering them to move to a particular location. In the first study a human pointed toward an empty cup. In one manipulation, the dog either knew or did not know that the designated cup was empty (and that the other cup actually contained the food). In another manipulation, the human (as authority) either did or did not remain in the room after pointing. Dogs ignored the human’s gesture if they had better information, irrespective of the authority’s presence. In the second study, we varied the level of authority of the person pointing. Sometimes this person was an adult, and sometimes a young child. Dogs followed children’s pointing just as frequently as they followed adults’ pointing (and ignored the dishonest pointing of both), suggesting that the level of authority did not affect their behavior. Taken together these studies suggest that dogs do not see pointing as an imperative command ordering them to a particular location. It is still not totally clear, however, if they interpret it as informative or in some other way.     

Do We Need Toleration as a Moral Virtue?

In this essay, I reconstruct tolerance as a moral virtue, by critically analysing its definition, circumstances, justification and limits. I argues that, despite its paradoxical appearance, tolerance qualifies as a virtue, by means of a restriction of its proper object to differences that are chosen. Since this excludes the most important and divisive differences of contemporary pluralism from the scope of the virtue of tolerance, the moral model of toleration cannot constitute the micro-foundation of the corresponding political practice. However, if the political ideal of toleration must be founded on independent political reasons of justice, the moral model can bridge the gap between private morality and public reason, providing citizens with moral motives to supplement the political obligation to neutrality. This revised version was published online in August 2006 with corrections to the Cover Date.     

Do rhesus monkeys (Macaca mulatta) perceive the Zöllner illusion?

A long-standing debate surrounds the issue of whether human and nonhuman animals share the same perceptual mechanisms. In humans, the Zöllner illusion occurs when two parallel lines appear to be convergent when oblique crosshatching lines are superimposed. Although one baboon study suggests that they too might perceive this illusion, the results of that study were unclear, whereas two recent studies suggest that birds see this illusion in the opposite direction from humans. It is currently unclear whether these mixed results are an artifact of the experimental design or reflect a peculiarity of birds’ visual system or, instead, a wider phenomenon shared among nonhuman mammals. Here, we trained 6 monkeys to select the narrower of two gaps at the end of two convergent lines. Three different conditions were set up: control (no crosshatches), perpendicular (crosshatches not inducing the illusion), and Zöllner (crosshatches inducing the illusion in humans). During training, the degrees of convergence between the two lines ranged from 15° to 12°. Monkeys that reached the training criterion were tested with more difficult discriminations (11°–1°), including probe trials with parallel lines (0°). The results showed that monkeys perceived the Zöllner illusion in the same direction as humans. Comparison of these data with the data from bird studies points toward the existence of different orientation-tuned mechanisms between primate and nonprimate species.     

Do production patterns influence the processing of speech in prelinguistic infants?

The headturn preference procedure was used to test 18 infants on their response to three different passages chosen to reflect their individual production patterns. The passages contained nonwords with consonants in one of three categories: (a) often produced by that infant (‘own’), (b) rarely produced by that infant but common at that age (‘other’), and (c) not generally produced by infants. Infants who had a single ‘own’ consonant showed no significant preference for either ‘own’ (a) or ‘other’ (b) passages. In contrast, infants’ with two ‘own’ consonants exhibited greater attention to ‘other’ passages (b). Both groups attended equally to the passage featuring consonants rarely produced by infants of that age (c). An analysis of a sample of the infant-directed speech ruled out the mothers’ speech as a source of the infant preferences. The production-based shift to a focus on the ‘other’ passage suggests that nascent production abilities combine with emergent perceptual experience to facilitate word learning.     

Do infants apply the principle of rational action to human agents?

Twelve- to fourteen-month-old infants’ reactions to violations of the principle of rational action [Cognition 56 (1995) 165] were studied in two experiments, using humanlike puppets and human agents rather than computerized shapes as stimuli. In Experiment 1, infants watched a puppet approaching another puppet on a stage, while in Experiment 2 a videotaped sequence of a person approaching another person was shown. In both experiments, a rational and a non-rational approach condition were contrasted in the habituation phase. In the rational approach condition, an obstacle had to be overcome by climbing or jumping. In the non-rational approach condition, the agent made a detour approach in the absence of an obstacle. In the test phase, infants watched direct and indirect-approach events. In both experiments, infants in the rational approach condition looked significantly longer at indirect-approach than at direct-approach test events, while no difference between the two types of test events was observed in the non-rational approach condition. These findings support the assumption that one-year-old infants have principled expectations about rational goal approaches of human agents.     

Do the eyes have it? Cues to the direction of social attention

The face communicates an impressive amount of visual information. We use it to identify its owner, how they are feeling and to help us understand what they are saying. Models of face processing have considered how we extract such meaning from the face but have ignored another important signal - eye gaze. In this article we begin by reviewing evidence from recent neurophysiological studies that suggests that the eyes constitute a special stimulus in at least two senses. First, the structure of the eyes is such that it provides us with a particularly powerful signal to the direction of another person's gaze, and second, we may have evolved neural mechanisms devoted to gaze processing. As a result, gaze direction is analysed rapidly and automatically, and is able to trigger reflexive shifts of an observer's visual attention. However, understanding where another individual is directing their attention involves more than simply analysing their gaze direction. We go on to describe research with adult participants, children and non-human primates that suggests that other cues such as head orientation and pointing gestures make significant contributions to the computation of another's direction of attention.