My face through the looking-glass: the effect of mirror reversal on reflection size estimation

People tend to grossly overestimate the size of their mirror-reflected face. Although this overestimation bias is robust, not much is known about its relationships to self-face perception. In two experiments, we investigated the overestimation bias as a function of the presentation of the own face (left–right reversed – as in a mirror – or nonreversed – as in a photograph), the identity of the seen face, and prior exposure to a real mirror. For this we developed a computerized task requiring size estimations of displayed faces. We replicated the observation that people overestimate the size of their mirror-reflected face and showed that the overestimation can be reduced following a brief mirror exposure. We also found that left–right reversal modulates the overestimation bias, depending on the perceived face’s identity. These data underline the enhanced familiarity of left–right reversed self-faces and the importance of size perception for understanding mirror reflection processing.     

Analysis of drivers’ behavior under reduced visibility conditions using a Structural Equation Modeling approach

One way to improve safety under reduced visibility conditions (i.e., reduce the chances of visibility related crashes) is to improve drivers’ behavior under such adverse weather conditions. The aim of this paper is to thoroughly examine drivers’ responses under low visibility conditions and quantify the impacts and values of various factors found to be related to drivers’ compliance and drivers’ satisfaction with variable speed limit (VSL) and changeable message signs (CMS) instructions in different visibility, traffic conditions, and on two types of roadways; freeways and two-lane roads.The data used for the analyses were obtained from a self-reported questionnaire survey carried out among 566 drivers in Central Florida, USA. To achieve these goals, Explanatory Factor Analysis (EFA) and Structural Equation Modeling (SEM) approaches were adopted.The results revealed that drivers’ satisfaction with VSL/CMS was the most significant factor that positively affected drivers’ compliance with advice or warning messages displayed on VSL/CMS under different fog conditions followed by human factors. Moreover, it was found that roadway type affected drivers’ compliance to VSL instructions under medium and heavy fog conditions. Furthermore, drivers’ familiarity with VSL and human factors were the significant factors affecting drivers’ satisfaction with VSL/CMS advice under reduced visibility conditions. Based on the findings of the present study, several recommendations are suggested as guidelines to improve drivers’ behavior in such reduced visibility conditions by enhancing drivers’ compliance with VSL/CMS instructions.     

Posture-related affordances guide attacks in basketball

Objectives

The purpose of this study was to investigate the decision made by the attacker to drive to the left or right of the defender.

Method

Participants were 32 novice and intermediate basketball players who were assigned the role of attacker or defender in a one-on-one subphase. We manipulated the defender’s posture and measured both the postures of defenders and attackers and the ensuing decision on drive direction.

Results

As hypothesized, the posture of defenders guided the decision behavior of the attacker. Both novice and intermediate attackers made the same affordance-based decision by driving to the side of the defender’s most advanced foot, but only when the distance between attacker and defender was small. Moreover, novice attackers conveyed postural information regarding their upcoming drive direction while intermediate attackers were better able to conceal this information.

Conclusions

These results lend further support to the notion of information-based control of interpersonal actions in sport contexts.     

Object-based auditory facilitation of visual search for pictures and words with frequent and rare targets

Auditory and visual processes demonstrably enhance each other based on spatial and temporal coincidence. Our recent results on visual search have shown that auditory signals also enhance visual salience of specific objects based on multimodal experience. For example, we tend to see an object (e.g., a cat) and simultaneously hear its characteristic sound (e.g., “meow”), to name an object when we see it, and to vocalize a word when we read it, but we do not tend to see a word (e.g., cat) and simultaneously hear the characteristic sound (e.g., “meow”) of the named object. If auditory–visual enhancements occur based on this pattern of experiential associations, playing a characteristic sound (e.g., “meow”) should facilitate visual search for the corresponding object (e.g., an image of a cat), hearing a name should facilitate visual search for both the corresponding object and corresponding word, but playing a characteristic sound should not facilitate visual search for the name of the corresponding object. Our present and prior results together confirmed these experiential association predictions. We also recently showed that the underlying object-based auditory–visual interactions occur rapidly (within 220 ms) and guide initial saccades towards target objects. If object-based auditory–visual enhancements are automatic and persistent, an interesting application would be to use characteristic sounds to facilitate visual search when targets are rare, such as during baggage screening. Our participants searched for a gun among other objects when a gun was presented on only 10% of the trials. The search time was speeded when a gun sound was played on every trial (primarily on gun-absent trials); importantly, playing gun sounds facilitated both gun-present and gun-absent responses, suggesting that object-based auditory–visual enhancements persistently increase the detectability of guns rather than simply biasing gun-present responses. Thus, object-based auditory–visual interactions that derive from experiential associations rapidly and persistently increase visual salience of corresponding objects.     

Modulating Fitts's Law: perceiving targets at the last placeholder

Fitts's Law predicts increasing movement times (MTs) with increasing movement amplitudes; however, when targets are placed in a structured perceptual array containing placeholders, MTs to targets in the last position are shorter than predicted. We conducted three experiments to determine if this modulation has a perceptual cause. Experiment 1, which used extremely diminished (three pixel) placeholders, showed that the modulation is not due to perceptual interference from neighboring placeholders. Experiment 2, which measured reaction times using a target detection task, showed that the modulation does not result from speeded perceptual processing at the last position of the array. Experiment 3, which measured accuracy using a masked letter-discrimination task, showed that the modulation does not result from the increased quality of perceptual representation at the last position of the array. Overall, these findings suggest that the changes in effectiveness of visual processing (less interference, speeded processing, and increased quality) at the last position in the perceptual array do not drive the modulation. Thus, while the locus of the Fitts's Law modulation appears to be in the movement planning stage, it is likely not due to perceptual mechanisms.     

Object-based attention: sensory enhancement or scanning prioritization

The three experiments reported here test whether object-modulated attentional spreading can be obtained when the target location is 100% certain. Experiment 1 uses the reaction time (RT)-based flanker task similar to Shomstein and Yantis (2002), and replicates the null result of the object-modulated attentional spreading. RT and accuracy (ACC) have been shown to reflect different processes: postperceptual decision vs. perceptual process (Santee & Egeth, 1982). Experiment 2 adopts the data-limited ACC-based measure and reports that attention could spread within the attended object. To avoid ceiling effects, Experiment 3 adjusts the presentation time based on the trials where the target and flankers were compatible and on the same objects, and provides the convergent evidence supporting the object-modulated attentional spreading. These results suggest that because the RT-based measure is less sensitive in reflecting the quality of perceptual representations, it is not sufficiently a strong evidence to distinguish between sensory enhancement and scanning prioritization accounts.     

Can buy me love: Mate attraction goals lead to perceptual readiness for status products

Exposure to mating cues activates the goal to signal one's mate value to members of the opposite sex. This mate attraction goal may render men perceptually ready for products that signal their mate value to women. As men's mate value is partly determined by their financial prospects, men may be more likely to notice products that would signal their financial resources to women. The current study demonstrates that exposure to a sexily dressed woman increases single men's likelihood of noticing status products in a visual display. Not only do these findings further support the link between conspicuous consumption and male mating strategies, they are the first to demonstrate perceptual readiness for indirect (i.e., products) rather than direct (i.e., opposite sex individuals) means for reproduction.     

Differential dynamics of spatial and non-spatial stimulus-response compatibility effects: a dual task LRP study

Choice reaction times are shorter when stimulus and response features are compatible rather than incompatible. Recent studies revealed that spatial compatibility effects in Simon tasks are strongly attenuated when there is temporal overlap with a different high-priority task. In contrast, non-spatial variants of the Simon task appear to be unaffected by task overlap. The present study used the lateralized readiness potential (LRP) within a dual task design to elucidate the dynamics underlying these differential effects for a color and a spatial variant of the Simon task. In the color version there was no sign of early response priming by irrelevant stimulus features in the LRP. The color compatibility effect was independent of task overlap and reflected in the LRP onset latency. In contrast, in the spatial version, priming by irrelevant stimulus location showed up and was mirrored by early LRP activation. Response priming and the corresponding Simon effect, however, were present only in case of little temporal overlap with the primary task. The absence of spatial compatibility effects at strong temporal overlap suggests that response conflicts due to stimulus-related priming depend on the availability of processing resources.     

Bayesian confusions surrounding simplicity and likelihood in perceptual organization

In the study of perceptual organization, the Occamian simplicity principle (which promotes efficiency) and the Helmholtzian likelihood principle (which promotes veridicality) have been claimed to be equivalent. Proposed models of these principles may well yield similar outcomes (especially in everyday situations), but as argued here, claims that the principles are equivalent confused subjective probabilities (which are used in Bayesian models of the Occamian simplicity principle) and objective probabilities (which are needed in Bayesian models of the Helmholtzian likelihood principle). Furthermore, Occamian counterparts of Bayesian priors and conditionals have led to another confusion, which seems to have been triggered by a dual role of regularity in perception. This confusion is discussed by contrasting complete and incomplete Occamian approaches to perceptual organization.     

The world in black and white: Ostracism enhances the categorical perception of social information

In two experiments, ostracized individuals showed more pronounced categorical perception of inclusion- and exclusion-related stimuli. Specifically, ostracism enhanced the ability to distinguish between-category differences (e.g., between happy and angry faces) relative to within-category differences (e.g., between two happy expressions). Participants were socially included or excluded via Cyberball (a virtual ball-tossing task). In Experiment 1, ostracized participants showed greater perceptual acuity in distinguishing between subtly happy and angry expressions combined with a reduced ability to discriminate expressions within each expression category. Experiment 2 found analogous categorical perception effects for targets varying on the dimension of race. Importantly, this effect was specific to social information; categorical perception of non-social objects was not qualified by social exclusion. These results suggest that ostracism exacerbates categorical perception, attuning perceivers to the differences between various inclusion- and exclusion-related categories relative to within category acuity, making the world appear more ‘black-and-white’ than it might otherwise.