Smartphones and rightward collisions.

People tend to deviate to the right when walking through a narrow aperture (e.g., a doorway), resulting in a rightward bias in collisions. This study examines the effects of smartphone use on rightward collisions while walking. When pedestrians walk through a narrow aperture, they usually head straight to the perceived centre of the aperture, which is shifted slightly to the right, without updating the estimates. The rightward shift of the perceived centre is attributable to the rightward attentional shift in the extrapersonal space. Pedestrians using smartphones tend to fixate on the phone most of the time and thus tend not to look at their surroundings (i.e., extrapersonal space). Therefore, we predict that smartphone use will reduce rightward collisions. To test this prediction, we used a narrow-doorway task in which participants walked through a narrow doorway either with or without a smartphone. The participants with smartphones used them to perform either verbal or spatial tasks. The number of rightward collisions decreased when the participants used smartphones. The type of task had no effect on the lateral collision biases. These results were interpreted in terms of lateral attentional bias in peripersonal and extrapersonal spaces.

Do you know your best side? Awareness of lateral posing asymmetries.

People tend to show the left cheek to broadly express emotions while they tend to show the right cheek to hide emotions because emotions were expressed more on the left than on the right side of the face. The present study investigated the level of awareness on the left- and right-cheek poses using the method of structural knowledge attributions. When asked to broadly express emotions for a family portrait, right-handed participants were more likely to show the left cheek than the right. On the other hand, when asked to conceal emotions to show a calm and reassuring attitude as a scientist, they were more likely to show the right cheek. After the posing session, participants selected the conscious level of their knowledge about posing from five categories: Random, intuition, familiarity, recollection, and rules. Most participants rated their knowledge as unconscious (i.e., either as random, intuition, or familiarity). The choice of the conscious level did not differ across posing orientations and posing instructions. These results suggest that although people do not have an acute awareness of their lateral posing preference, they reliably show one side of their faces to express or hide emotions.

The malfunction of domain-specific attentional process in social anxiety: attentional process of social and non-social stimuli.

Socially anxious people have a malfunction in attentional systems. However, it is uncertain whether the malfunction of the attentional system is a domain-specific process to social stimuli or a domain-general process to non-social stimuli. Therefore, we investigated the effects of social anxiety on the domain specificity of the attentional process using a spatial Stroop paradigm. We conducted two identical experiments with a total of 153 university students including men and women (61 students in Experiment 1 and 92 students in Experiment 2), in which the levels of social anxiety were assessed using specific instruments. The results showed that social anxiety scores were negatively correlated with the reversed spatial Stroop effect for social stimuli, but not for non-social stimuli (Experiment 1). The findings of the first experiment were successfully replicated in Experiment 2. Our results suggested that the malfunction of the attentional system is a domain-specific process to socially threatening stimuli in socially anxious individuals.

Faces of glory: the left-cheek posing bias for medallists of Brazilian jiu-jitsu competitions.

Laboratory studies have shown that people tend to show the left side of their face when asked to broadly express emotions, while they tend to show the right side when asked to hide emotions. Because emotions are expressed more intensely in the left side of the face, it is hypothesized that an individual's intention to express or hide emotions biases the direction of lateral facial poses. The present study tested this hypothesis using photographic portraits of individuals experiencing emotional events in a naturalistic setting: the reception of medals in Brazilian jiu-jitsu competitions. Portrait photographs of Brazilian jiu-jitsu competitors were sourced online (N = 460) and were rated by two independent raters in terms of posing direction, emotional expression, and medal colour. Gold and silver medallists showed their left cheeks to the camera for commemorative photographs taken immediately after the medal ceremony. Positive emotions were expressed more often for gold medallists than silver ones. The left-cheek posing bias observed in the present study supports the hypothesis that the intended purpose of expressing or hiding emotions determines the direction of lateral posing biases, and extends the laboratory findings to situations in the real world.

The big warm smile of cheaters: lateral posing biases and emotional expressions in displaying facial trustworthiness.

Cheater detection, which is a prerequisite for the evolution of social cooperation, has been successfully simulated in laboratory settings. However, the process has not been perfect because the detection rate has usually been just above chance. The present study investigated the role of lateral posing biases and emotional expressions in displaying trustworthiness, which plays a crucial role in cheater detection. Participants (N = 30 and 28 in Experiments 1 and 2, respectively) observed facial photographs of cheaters and cooperators in an economic game and evaluated their facial expressions in terms of emotional valence and arousal. The models in the photographs had turned their left or right cheek to the camera to display their trustworthiness in the economic game. The results indicated that cheaters showing their left cheek were rated as more emotionally positive than cheaters showing their right cheek. This lateral difference was not observed for cooperators. A left cheek advantage in emotional arousal was found for both cheaters and cooperators. These results suggest that cheaters use a fake smile on the emotional side of their face (i.e., the left) to conceal their uncooperative attitude.

The cheek of a cheater: Effects of posing the left and right hemiface on the perception of trustworthiness.

Our cognitive mechanisms are designed to detect cheaters in social exchanges. However, cheater detection can be thwarted by a posed smile, which cheaters display with greater emotional intensity than cooperators. The present study investigated the role of hemifacial asymmetries in the perception of trustworthiness using face photographs with left and right cheek poses. Participants (N = 170) observed face photographs of cheaters and cooperators in an economic game. In the photographs, models expressed happiness or anger and turned slightly to the left or right to show their left or right cheeks to the camera. When the models expressed anger on their faces, cheaters showing the right cheek were rated as less trustworthy than cooperators (irrespective of cheeks shown) and cheaters showing the left cheek. When the models expressed happiness, trustworthiness ratings increased and did not differ between cheaters and cooperators, and no substantial asymmetries were observed. These patterns were replicated even when the face photographs were mirror-reversed. These results suggest that a cheater's fake smile conceals an uncooperative attitude that is displayed in the right hemiface, ultimately disguising cheater detection.

[Assessment of working memory capacity with a Japanese version of the Operation Span Test].

The Operation Span Test (OSPAN) is widely used to assess working memory capacity. However, this instrument has been rarely used to test Japanese participants because its task was not sufficiently difficult. The mean score for the original computerized OSPAN often reached a ceiling when Japanese participants were tested. In this study, we developed a computerized version of OSPAN for Japanese participants by increasing the task difficulty of the arithmetic procedures. The OSPAN scores were normally distributed and the mean score was approximately 50%. There were positive correlations between OSPAN scores and other scores of working memory measurements, such as a reading span test and a digit span test. These results suggest that the Japanese OSPAN is a reliable and valid measurement of working memory to test Japanese participants.

[A Japanese version of the FLANDERS handedness questionnaire].

Quantitative assessment of handedness is required in various clinical and research settings in psychology, neuroscience, and medicine. In the present study we tested the reliability and validity of a Japanese version of the FLANDERS handedness questionnaire, which was a new measure of skilled hand preference originally reported by Nicholls, Thomas, Loetscher, and Grimshaw (2013). Participants (N=431) completed three types of handedness questionnaires: the FLANDERS handedness questionnaire, Edinburgh Handedness Inventory, and H · N handedness test. Factor analysis revealed that the Japanese version of FLANDERS handedness questionnaire had a single-factor structure and high internal consistency. This questionnaire also posssed high test-retest reliability and criterion-referenced validity. These results indicate that the Japanese version of the FLANDERS handedness questionnaire is a valid and useful measure of skilled hand preference for Japanese participants.

[The effect of interpersonal dependency on judgment of gaze direction].

This study investigated the effect of interpersonal dependency on judgments of gaze direction of individuals with different facial expressions. Based on interpersonal dependency scores, 46 participants were divided into two groups (high interpersonal dependency and low interpersonal dependency). Participants judged the gaze direction of photographs of faces with angry, neutral or happy expressions. Relative to the low interpersonal dependency group, the high interpersonal dependency group was more accurate in the judgments of gaze direction. This tendency was more salient for the happy and neutral expressions than for the angry expressions. Since people with high interpersonal dependency are highly motivated to seek support from others, this result suggests that they are sensitive to signals with pro-social information such as the gaze direction of others with positive attitudes.

Reversing the reversed congruency effect: directional salience overrides social significance in a spatial Stroop task.

In a spatial Stroop task, eye-gaze targets produce a reversed congruency effect (RCE) with faster responses when gaze direction and location are incongruent than congruent. On the other hand, non-social directional targets (e.g., arrows) elicit a spatial Stroop effect (SSE). The present study examined whether other social stimuli, such as head orientation, trigger the RCE. Participants judged the target direction of the head or the gaze while ignoring its location. While the gaze target replicated the RCE, the head target produced the SSE. Moreover, the head target facilitated the overall responses relative to the gaze target. These results suggest that the head, a salient directional feature, overrides the social significance. The RCE may be specific to gaze stimuli, not to social stimuli in general. The head and gaze information differentially affect our attentional mechanisms and enable us to bring about smooth social interactions.

Perceiving social gaze produces the reversed congruency effect.

Numerous studies have shown that the gaze of others produces a special attentional process, such as the eye contact effect or joint attention. This study investigated the attentional process triggered by various types of gaze stimuli (i.e., human, cat, fish, koala, and robot gaze). A total of 300 university students participated in five experiments. They performed a spatial Stroop task in which five types of gaze stimuli were presented as targets. Participants were asked to judge the direction of the target (left or right) irrespective of its location (left or right). The results showed that the social gaze targets (i.e., human and cat gaze) produced a reversed congruency effect. In contrast to the social gaze targets, the non-social gaze (i.e., fish and robot) target did not produce the reversed congruency effect (Experiments 2, 2B, 3, and 4). These results suggest that attention to the gaze of socially communicable beings (i.e., humans and cats) is responsible for the reversed congruency effect. Our findings support the notion that the theory of mind or social interaction plays an important role in producing specific attentional processes in response to gaze stimuli.

No trust on the left side: hemifacial asymmetries for trustworthiness and emotional expressions.

People can discriminate cheaters from cooperators by their appearance. However, successful cheater detection can be thwarted by a posed smile, which cheaters display with greater emotional intensity than cooperators. The present study investigated the underlying neural and cognitive mechanisms of a posed smile, which cheaters use to conceal their anti-social attitude, in terms of hemifacial asymmetries of emotional expressions. Raters (50 women and 50 men) performed trustworthiness judgments on composite faces of cheaters and cooperators, operationally defined by the number of deceptions in an economic game. The left-left composites of cheaters were judged to be more trustworthy than the right-right composites when the models posed a happy expression. This left-hemiface advantage for the happy expression was not observed for cooperators. In addition, the left-hemiface advantage of cheaters disappeared for the angry expression. These results suggest that cheaters used the left hemiface, which is connected to the emotional side of the brain (i.e., the right hemisphere), more effectively than the right hemiface to conceal their anti-social attitude.

Face inversion does not affect the reversed congruency effect of gaze.

In a spatial Stroop task, the eye-gaze target produces the reversed congruency effect-responses become shorter when the gaze direction and its location are incongruent than when they are congruent. The present study examined the face inversion effect on the gaze spatial Stroop task to clarify whether the holistic face processing or part-based processing of the eyes is responsible for the reversed congruency effect. In Experiment 1, participants judged the gaze direction of the upright or inverted face with a neutral expression presented either in the left or right visual field. In Experiment 2, we examined whether face inversion interacted with facial expressions (i.e., angry, happy, neutral, and sad). Face inversion disrupted holistic face processing, slowing down the overall performance relative to the performance with upright faces. However, face inversion did not affect the reversed congruency effect. These results further support the parts-based processing account and suggest that while faces are processed holistically, the reversed congruency effect, relying on the extracted local features (i.e., eyes), may be processed in a part-based manner.

Eye gaze is not unique: The reversed congruency effect on gaze and tongue targets.

In the spatial Stroop task, an arrow target produces a spatial Stroop effect, whereas a gaze target elicits a reversed congruency effect. The reversed congruency effect has been explained by the unique attentional mechanisms of eye gaze. However, recent studies have shown that not only gaze but arrow targets produced a reversed congruency effect when embedded in a complex background. The present study investigated whether non-gaze targets produce a reversed congruency effect. In Experiments 1 and 2, we used the tongue, which is not commonly used to indicate spatial directions in daily life, as a target in the spatial Stroop task, in addition to the conventional gaze and arrows. In Experiment 3, we used arrow stimuli embedded in a complex background as a target. Participants judged the left/right direction of the target presented in the left or right visual field. Although arrow and gaze targets replicated previous findings (spatial Stroop and reversed congruency effect, respectively), the tongue target produced a reversed congruency effect (Experiments 1 and 2). The spatial Stroop effect of arrow targets disappeared when they were in a complex background (Experiment 3). These results are inconsistent with previous accounts emphasising the unique status of eye gaze. We propose that temporal decay of the location code and response inhibition are responsible for the reversal of spatial interference.

[Judgment of gaze direction related to social anxiety: facial expressions and interpretation biases].

The present study investigated the effects of social anxiety on judgments about gaze direction. The participants (N = 123) were divided into two groups on the basis of social anxiety scores (social anxiety and control group). Participants who scored high on a social anxiety scale judged the direction of slightly averted gaze to be straight more often for angry faces than for neutral faces. This pattern was reversed for participants in control group. An angry face looking straight at a person may be seen as an overt threat. People suffering from social anxiety tend to interpret ambiguous situations as negative or threatening. This negativity bias may contribute to the increased judgments of straight-gaze responses for angry faces with slightly averted gazes.

Effects of the global and local attention on the processing of categorical and coordinate spatial relations.

Participants made categorical or coordinate spatial judgments on the global or local elements of shapes. Stimuli were composed of a horizontal line and two dots. In the Categorical task, participants judged whether the line was above or below the dots. In the Coordinate task, they judged whether the line would fit between the dots. Stimuli were made hierarchical so that the global patterns composed of a "global line" made of local dots-and-line units, and "global dot" made of a single dots-and-line unit. The results indicated that the categorical task was better performed when participants attended to the local level of the hierarchical stimuli. On the other hand, the coordinate task was better performed when they attended to the global level. These findings are consistent with computer simulation models of the attentional modulation of neuronal receptive fields' size suggesting that (1) coordinate spatial relations are more efficiently encoded when one attends to a relatively large region of space, whereas (2) categorical spatial relations are more efficiently encoded when one attends to a relatively small region of space.

Lateral biases and reading direction: a dissociation between aesthetic preference and line bisection.

Perceptual asymmetries for tasks involving aesthetic preference or line bisection can be affected by asymmetrical neurological mechanisms or left/right reading habits. This study investigated the relative contribution of these mechanisms in 100 readers of Japanese and English. Participants made aesthetic judgments between pairs of mirror-reversed pictures showing: (a) static objects, (b) moving objects and (c) landscapes. A line bisection task was also administered. There was a strong effect of reading direction for static and mobile objects whereby Japanese readers preferred objects with a right-to-left directionality (and vice versa for English readers). In contrast, similar patterns were observed for the Japanese and English readers for the landscape and line bisection tasks. The results show that reading habits affect aesthetic judgments for static and moving object tasks, but not the landscape and line bisection tasks. The difference between the tasks may be related to the horizontal/vertical geometry of the stimuli, which makes the landscape and line bisection tasks more prone to universal effects related to cerebral dominance.

Automatic semantic association between emotional valence and brightness in the right hemisphere.

Positive words (e.g., faith) were recognised better when presented in white fonts than in black fonts, whereas the opposite was true for negative words (e.g., enemy). A neural basis for this type of association between emotional valence and brightness was investigated using a visual half-field paradigm. Positive and negative words were presented in black or white fonts and presented to the left visual field-right hemisphere (LVF-RH) or right visual field-left hemisphere (RVF-LH) in a word valence judgement task (i.e., positive vs. negative). A cross-over interaction between emotional valence and brightness was observed; valence judgements were facilitated when a positive word appeared in white and when a negative word appeared in black. This interaction was qualified by a higher-order interaction. The cross-over interaction appeared only for LVF-RH trials, suggesting that the right hemisphere was responsible for the association between emotional valence and brightness.

Filtered beauty in Oslo and Tokyo: A spatial frequency analysis of facial attractiveness.

Images of European female and male faces were digitally processed to generate spatial frequency (SF) filtered images containing only a narrow band of visual information within the Fourier spectrum. The original unfiltered images and four SF filtered images (low, medium-low, medium-high and high) were then paired in trials that kept constant SF band and face gender and participants made a forced-choice decision about the more attractive among the two faces. In this way, we aimed at identifying those specific SF bands where forced-choice preferences corresponded best to forced-choice judgements made when viewing the natural, broadband, facial images. We found that aesthetic preferences dissociated across SFs and face gender, but similarly for participants from Asia (Japan) and Europe (Norway). Specifically, preferences when viewing SF filtered images were best related to the preference with the broadband face images when viewing the highest filtering band for the female faces (about 48-77 cycles per face). In contrast, for the male faces, the medium-low SF band (about 11-19 cpf) related best to choices made with the natural facial images. Eye tracking provided converging evidence for the above, gender-related, SF dissociations. We suggest greater aesthetic relevance of the mobile and communicative parts for the female face and, conversely, of the rigid, structural, parts for the male face for facial aesthetics.

Correction: Filtered beauty in Oslo and Tokyo: A spatial frequency analysis of facial attractiveness.

[This corrects the article DOI: 10.1371/journal.pone.0227513.].