Investigation of Cross-Language and Stimulus-Dependent Effects on the McGurk Effect with Finnish and Japanese Speakers and Listeners.

In the McGurk effect, perception of a spoken consonant is altered when an auditory (A) syllable is presented with an incongruent visual (V) syllable (e.g., A/pa/V/ka/ is often heard as /ka/ or /ta/). The McGurk effect provides a measure for visual influence on speech perception, becoming stronger the lower the proportion of auditory correct responses. Cross-language effects are studied to understand processing differences between one's own and foreign languages. Regarding the McGurk effect, it has sometimes been found to be stronger with foreign speakers. However, other studies have shown the opposite, or no difference between languages. Most studies have compared English with other languages. We investigated cross-language effects with native Finnish and Japanese speakers and listeners. Both groups of listeners had 49 participants. The stimuli (/ka/, /pa/, /ta/) were uttered by two female and male Finnish and Japanese speakers and presented in A, V and AV modality, including a McGurk stimulus A/pa/V/ka/. The McGurk effect was stronger with Japanese stimuli in both groups. Differences in speech perception were prominent between individual speakers but less so between native languages. Unisensory perception correlated with McGurk perception. These findings suggest that stimulus-dependent features contribute to the McGurk effect. This may have a stronger influence on syllable perception than cross-language factors.

Backward illusory line motion: Visual motion perception can be influenced by retrospective stimulation.

When a visual cue appears beside a horizontal line segment before the line appears, the illusory motion is perceived as a line extending from the side closest to the side farthest from the cue. This is known as illusory line motion (ILM). In Experiment 1, we presented the cue after the line onset and found that the line seemed to extend toward the side of the cue (backward ILM). In Experiment 2, we confirmed the robustness and replicability of the backward ILM. In Experiments 3 to 5, we investigated the role of endogenous and exogenous attention in the generation of backward ILM and found effects of attention, but not large enough to explain the backward ILM in Experiments 1 and 2. The current findings suggest that the direction of ILM depended on the temporal relation of whether the cue precedes or follows the stimulus appearance, and that attentional shift played a role in the perception of backward ILM.

Validation of the Japanese version of the Interoception Sensory Questionnaire for individuals with autism spectrum disorder.

The Interoception Sensory Questionnaire (ISQ) is a self-report instrument used to assess the characteristics of interoceptive processing in individuals with autism spectrum disorder (ASD). Previous studies have shown that scores of the ISQ are more appropriate than other subjective measures for evaluating difficulties in interoceptive processing in individuals with ASD. Yet, no prior research has demonstrated the validation of the ISQ in Japanese samples. This study attempted to validate the Japanese version of the ISQ (ISQ-J) by examining its psychometric properties. We confirmed the score distribution, internal consistency, and factor structure in Japanese samples. We also examined the relationships with other interoceptive questionnaires. In addition, we compared the scores of the ISQ-J between adolescents and adults with ASD participants and control participants. Results of confirmatory factor analyses showed that the reliability of the ISQ-J in adults with ASD reached an acceptable level of a one-factor structure with excellent internal consistency (α = 0.963). The result of the ISQ-J showed a significant positive correlation with the measure of awareness of interoceptive sensitivity for localized bodily states; on the other hand, a significant negative correlation was found with those integrated bodily states. In addition, the ISQ-J scores were significantly higher in the ASD group than in the control group. The current findings depend on self-report data (including a diagnosis of ASD) to measure validity constructs. Additionally, since the ISQ-J was surveyed in adults with ASD, it is unclear whether similar the results would be obtained if the ISQ-J were conducted with children. These results indicate the validity and reliability of the ISQ-J and provide a tool for assessing confusion of interoceptive information in Japanese adults with ASD.

Subjective Sensitivity to Exteroceptive and Interoceptive processing in Highly Sensitive Person.

A highly sensitive person is known to have greater levels of sensory processing sensitivity (SPS) referring to a personality trait to exhibit high stimulation and arousal while processing subtle sensory signals. However, how SPS levels reflect the profile of sensitivity in exteroceptive and interoceptive sensory processing remains inadequately understood. Thus, we collected data using the Highly Sensitive Person Scale (HSPS), the Glasgow Sensory Questionnaire (GSQ), and the Body Perception Questionnaire-Short Form (BPQ-SF) from 600 Japanese adults, and examined their relationships. The results revealed that SPS levels, assessed by the HSPS, were significantly, positively correlated with hypersensitivity scores of the GSQ in several exteroceptive sensory domains. Further, SPS levels were positively correlated with sensitivity in interoceptive awareness assessed by the BPQ-SF; however, it does so scarcely. Our findings suggest that SPS levels reflect a subjective sensitivity to exteroceptive sensory processing regardless of sensory domains and narrowly to the interoceptive sensory processing.

Own-race faces promote integrated audiovisual speech information.

The other-race effect indicates a perceptual advantage when processing own-race faces. This effect has been demonstrated in individuals' recognition of facial identity and emotional expressions. However, it remains unclear whether the other-race effect also exists in multisensory domains. We conducted two experiments to provide evidence for the other-race effect in facial speech recognition, using the McGurk effect. Experiment 1 tested this issue among East Asian adults, examining the magnitude of the McGurk effect during stimuli using speakers from two different races (own-race vs. other-race). We found that own-race faces induced a stronger McGurk effect than other-race faces. Experiment 2 indicated that the other-race effect was not simply due to different levels of attention being paid to the mouths of own- and other-race speakers. Our findings demonstrated that own-race faces enhance the weight of visual input during audiovisual speech perception, and they provide evidence of the own-race effect in the audiovisual interaction for speech perception in adults.

Association of personality with habituation of physical and non-physical activities among Japanese adults: Results from questionnaire research before COVID-19 pandemic.

Background: Physical activity has benefits for public health as it reduces the risk of non-communicable diseases and improves the quality of life. Previous studies have shown that health conditions, lifestyle, and socioeconomic status influence one's tendency to engage in physical activity. However, the influence of psychological traits on engagement in physical activity is not yet fully understood. In this study, we explored personality traits associated with the habituation of physical activity and compared them with personality traits associated with the habituation of non-physical activity. Methods: We recruited 1600 Japanese adult volunteers and conducted an online survey just before the spread of COVID-19. We collected data for the prevalence of physical and non-physical activities, and various aspects of personality traits including the Big Five personality traits, sensitivity to behavioral activation, dark triad personality, levels of internal locus of control, and the degree of just-world belief. Findings: The results demonstrated that high levels of extraversion, sensitivity to behavioral activation, and an internal locus of control had a positive influence on the habituation of physical activity. Moreover, our results were contradictory as they also showed that high levels of openness, sensitivity to behavioral activation, and just world belief related to the habituation of non-physical activity. Interpretation: These results suggest that the personality traits that influenced the habituation of activities depend on the characteristics of the activity and reveal extraversion and internal locus of control as the personality traits specific to the habituation of physical activity. Fundings: This study was supported by Senryakuteki-kenkyu from Chukyo University, a Grant-in-Aid for Early-Career Scientists (Grant No. 19 K20650 and 22 K13880), the Promotion of Joint International Research (Grant No. 20KK0054). This work was also supported by a Grant-in-Aid for Scientific Research on Innovative Areas "Construction of the Face-Body Studies in Transcultural Conditions" (Grant No. 17H06342).

Weaker McGurk Effect for Rubin's Vase-Type Speech in People With High Autistic Traits.

While visual information from facial speech modulates auditory speech perception, it is less influential on audiovisual speech perception among autistic individuals than among typically developed individuals. In this study, we investigated the relationship between autistic traits (Autism-Spectrum Quotient; AQ) and the influence of visual speech on the recognition of Rubin's vase-type speech stimuli with degraded facial speech information. Participants were 31 university students (13 males and 18 females; mean age: 19.2, SD: 1.13 years) who reported normal (or corrected-to-normal) hearing and vision. All participants completed three speech recognition tasks (visual, auditory, and audiovisual stimuli) and the AQ-Japanese version. The results showed that accuracies of speech recognition for visual (i.e., lip-reading) and auditory stimuli were not significantly related to participants' AQ. In contrast, audiovisual speech perception was less susceptible to facial speech perception among individuals with high rather than low autistic traits. The weaker influence of visual information on audiovisual speech perception in autism spectrum disorder (ASD) was robust regardless of the clarity of the visual information, suggesting a difficulty in the process of audiovisual integration rather than in the visual processing of facial speech.

Psychometric properties of the Family Allocentrism Scale among Japanese adults.

The Family Allocentrism Scale (FAS) was developed to assess individual differences in allocentrism-idiocentrism with reference to the family. To date, no prior study has adequately investigated the psychometric properties of the Japanese version of the FAS in Japanese samples, although Japanese culture is considered as a symbol of an interdependent (or collectivist) culture. This study attempted to demonstrate the validity of the factor structure and the convergent validity of the Japanese version of the FAS in a sample of Japanese adults. The results of the confirmatory factor analysis showed a lack of fit of the one-factor model for all FAS items but the fit improved to the acceptable level if some items with low factor loadings were removed. The internal consistency measure (Cronbach's alpha) of the FAS indicated an acceptable level of reliability. The results also showed that the FAS scores were closely related to the scores of horizontal collectivism, vertical collectivism, and interdependence. Our findings indicate the validity and reliability of the Japanese version of the FAS, thereby providing a validated tool for the investigation of cross-cultural differences in family allocentrism-idiocentrism.

Switch or stay? Automatic classification of internal mental states in bistable perception.

The human brain goes through numerous cognitive states, most of these being hidden or implicit while performing a task, and understanding them is of great practical importance. However, identifying internal mental states is quite challenging as these states are difficult to label, usually short-lived, and generally, overlap with other tasks. One such problem pertains to bistable perception, which we consider to consist of two internal mental states, namely, transition and maintenance. The transition state is short-lived and represents a change in perception while the maintenance state is comparatively longer and represents a stable perception. In this study, we proposed a novel approach for characterizing the duration of transition and maintenance states and classified them from the neuromagnetic brain responses. Participants were presented with various types of ambiguous visual stimuli on which they indicated the moments of perceptual switches, while their magnetoencephalogram (MEG) data were recorded. We extracted different spatio-temporal features based on wavelet transform, and classified transition and maintenance states on a trial-by-trial basis. We obtained a classification accuracy of 79.58% and 78.40% using SVM and ANN classifiers, respectively. Next, we investigated the temporal fluctuations of these internal mental representations as captured by our classifier model and found that the accuracy showed a decreasing trend as the maintenance state was moved towards the next transition state. Further, to identify the neural sources corresponding to these internal mental states, we performed source analysis on MEG signals. We observed the involvement of sources from the parietal lobe, occipital lobe, and cerebellum in distinguishing transition and maintenance states. Cross-conditional classification analysis established generalization potential of wavelet features. Altogether, this study presents an automatic classification of endogenous mental states involved in bistable perception by establishing brain-behavior relationships at the single-trial level.

Neural correlates of online cooperation during joint force production.

During joint action, two or more persons depend on each other to accomplish a goal. This mutual recursion, or circular dependency, is one of the characteristics of cooperation. To evaluate the neural substrates of cooperation, we conducted a hyperscanning functional MRI study in which 19 dyads performed a joint force-production task. The goal of the task was to match their average grip forces to the target value (20% of their maximum grip forces) through visual feedback over a 30-s period; the task required taking into account other-produced force to regulate the self-generated one in real time, which represented cooperation. Time-series data of the dyad's exerted grip forces were recorded, and the noise contribution ratio (NCR), a measure of influence from the partner, was computed using a multivariate autoregressive model to identify the degree to which each participant's grip force was explained by that of their partner's, i.e., the degree of cooperation. Compared with the single force-production task, the joint task enhanced the NCR and activated the mentalizing system, including the medial prefrontal cortex, precuneus, and bilateral posterior subdivision of the temporoparietal junction (TPJ). In addition, specific activation of the anterior subdivision of the right TPJ significantly and positively correlated with the NCR across participants during the joint task. The effective connectivity of the anterior to posterior TPJ was upregulated when participants coordinated their grip forces. Finally, the joint task enhanced cross-brain functional connectivity of the right anterior TPJ, indicating shared attention toward the temporal patterns of the motor output of the partner. Since the posterior TPJ is part of the mentalizing system for tracking the intention of perceived agents, our findings indicate that cooperation, i.e., the degree of adjustment of individual motor output depending on that of the partner, is mediated by the interconnected subdivisions of the right TPJ.

The Object Orientation Effect in Exocentric Distances.

The object orientation effect describes shorter perceived distances to the front than to the back of oriented objects. The present work extends previous studies in showing that the object orientation effect occurs not only for egocentric distances between an observer and an object, but also for exocentric distances, that are between two oriented objects. Participants watched animated virtual humans (avatars) which were either facing each other or looking away, and afterward adjusted a bar to estimate the perceived length. In two experiments, participants judged avatars facing each other as closer than avatars facing away from each other. As the judged distance was between two objects and did not involve the observer, results rule out an explanation that observers perceive object fronts as closer to prepare for future interaction with them. The second experiment tested an explanation by predictive coding, this is the extrapolation of the current state of affairs to likely future states here that avatars move forward. We used avatars standing on bridges either connecting them or running orthogonal to the inter-avatar line thus preventing forward movement. This variation of walkability did not influence participants' judgments. We conclude that if predictive coding was used by participants, they did not consider the whole scene layout for prediction, but concentrated on avatars. Another potential explanation of the effect assumes a general asymmetrical distribution of inter-person distances: people facing each other might typically be closer to each other than when facing away and that this asymmetry is reflected as a bias in perception.

The Relationship between Neurite Density Measured with Confocal Microscopy in a Cleared Mouse Brain and Metrics Obtained from Diffusion Tensor and Diffusion Kurtosis Imaging.

PURPOSE: Diffusional kurtosis imaging (DKI) enables sensitive measurement of tissue microstructure by quantifying the non-Gaussian diffusion of water. Although DKI is widely applied in many situations, histological correlation with DKI analysis is lacking. The purpose of this study was to determine the relationship between DKI metrics and neurite density measured using confocal microscopy of a cleared mouse brain. METHODS: One thy-1 yellow fluorescent protein 16 mouse was deeply anesthetized and perfusion fixation was performed. The brain was carefully dissected out and whole-brain MRI was performed using a 7T animal MRI system. DKI and diffusion tensor imaging (DTI) data were obtained. After the MRI scan, brain sections were prepared and then cleared using aminoalcohols (CUBIC). Confocal microscopy was performed using a two-photon confocal microscope with a laser. Forty-eight ROIs were set on the caudate putamen, seven ROIs on the anterior commissure, and seven ROIs on the ventral hippocampal commissure on the confocal microscopic image and a corresponding MR image. In each ROI, histological neurite density and the metrics of DKI and DTI were calculated. The correlations between diffusion metrics and neurite density were analyzed using Pearson correlation coefficient analysis. RESULTS: Mean kurtosis (MK) (P = 5.2 × 10-9, r = 0.73) and radial kurtosis (P = 2.3 × 10-9, r = 0.74) strongly correlated with neurite density in the caudate putamen. The correlation between fractional anisotropy (FA) and neurite density was moderate (P = 0.0030, r = 0.42). In the anterior commissure and the ventral hippocampal commissure, neurite density and FA are very strongly correlated (P = 1.3 × 10-5, r = 0.90). MK in these areas were very high value and showed no significant correlation (P = 0.48). CONCLUSION: DKI accurately reflected neurite density in the area with crossing fibers, potentially allowing evaluation of complex microstructures.

Curvature Blindness Illusion.

We report a novel illusion--curvature blindness illusion: a wavy line is perceived as a zigzag line. The following are required for this illusion to occur. First, the luminance contrast polarity of the wavy line against the background is reversed at the turning points. Second, the curvature of the wavy line is somewhat low; the right angle is too steep to be perceived as an illusion. This illusion implies that, in order to perceive a gentle curve, it is necessary to satisfy more conditions--constant contrast polarity--than perceiving an obtuse corner. It is notable that observers exactly "see" an illusory zigzag line against a physically wavy line, rather than have an impaired perception. We propose that the underlying mechanisms for the gentle curve perception and those of obtuse corner perception are competing with each other in an imbalanced way and the percepts of corner might be dominant in the visual system.

The Influence of Human Body Orientation on Distance Judgments.

People maintain larger distances to other peoples' front than to their back. We investigated if humans also judge another person as closer when viewing their front than their back. Participants watched animated virtual characters (avatars) and moved a virtual plane toward their location after the avatar was removed. In Experiment 1, participants judged avatars, which were facing them as closer and made quicker estimates than to avatars looking away. In Experiment 2, avatars were rotated in 30 degree steps around the vertical axis. Observers judged avatars roughly facing them (i.e., looking max. 60 degrees away) as closer than avatars roughly looking away. No particular effect was observed for avatars directly facing and also gazing at the observer. We conclude that body orientation was sufficient to generate the asymmetry. Sensitivity of the orientation effect to gaze and to interpersonal distance would have suggested involvement of social processing, but this was not observed. We discuss social and lower-level processing as potential reasons for the effect.

Mental Summation of Temporal Duration within and across Senses.

Perceiving, memorizing, and estimating temporal durations are key cognitive functions in everyday life. In this study, a duration summation paradigm was used to examine whether summation of temporal durations introduces an underestimation or overestimation bias, and whether this bias is common to visual and auditory modalities. Two within- or across-modality stimuli were presented sequentially for variable durations. Participants were asked to reproduce the sum of the two durations (0.6-1.1 s). We found that the sum of two durations was overestimated regardless of stimulus modalities. A subsequent control experiment indicated that the overestimation bias arose from the summation process, not perceptual or memory processes. Furthermore, we observed strong positive correlations between the overestimation bias for different sensory modalities within participants. These results suggest that the sum of two durations is overestimated, and that supra-modal processes may be responsible for this overestimation bias.

Impact of stimulus uncanniness on speeded response.

In the uncanny valley phenomenon, the causes of the feeling of uncanniness as well as the impact of the uncanniness on behavioral performances still remain open. The present study investigated the behavioral effects of stimulus uncanniness, particularly with respect to speeded response. Pictures of fish were used as visual stimuli. Participants engaged in direction discrimination, spatial cueing, and dot-probe tasks. The results showed that pictures rated as strongly uncanny delayed speeded response in the discrimination of the direction of the fish. In the cueing experiment, where a fish served as a task-irrelevant and unpredictable cue for a peripheral target, we again observed that the detection of a target was slowed when the cue was an uncanny fish. Conversely, the dot-probe task suggested that uncanny fish, unlike threatening stimulus, did not capture visual spatial attention. These results suggested that stimulus uncanniness resulted in the delayed response, and importantly this modulation was not mediated by the feelings of threat.

Synchronous motion modulates animacy perception.

Visual motion serves as a cue for high-level percepts. The present study reports novel modulation of animacy perception through synchronous motion. A target dot moving along a random trajectory was presented. The trajectory was generated based on a variant of 1/f noise; hence, the dot could be perceived as animate. Participants were asked to rate the strength of perceived animacy and perceived intention from the target dot. Several task-irrelevant dots surrounding the target were also presented. Results indicated that perceived animacy and intention were drastically weakened when surrounding dots created synchronous motion with the target dot as compared to when surrounding dots did not create synchronous motion. A series of follow-up experiments replicated these results and revealed specific characteristics of this modulation. The present findings suggest synchronous visual motion serves as a strong modulator of animacy perception.

Seeing Objects as Faces Enhances Object Detection.

The face is a special visual stimulus. Both bottom-up processes for low-level facial features and top-down modulation by face expectations contribute to the advantages of face perception. However, it is hard to dissociate the top-down factors from the bottom-up processes, since facial stimuli mandatorily lead to face awareness. In the present study, using the face pareidolia phenomenon, we demonstrated that face awareness, namely seeing an object as a face, enhances object detection performance. In face pareidolia, some people see a visual stimulus, for example, three dots arranged in V shape, as a face, while others do not. This phenomenon allows us to investigate the effect of face awareness leaving the stimulus per se unchanged. Participants were asked to detect a face target or a triangle target. While target per se was identical between the two tasks, the detection sensitivity was higher when the participants recognized the target as a face. This was the case irrespective of the stimulus eccentricity or the vertical orientation of the stimulus. These results demonstrate that seeing an object as a face facilitates object detection via top-down modulation. The advantages of face perception are, therefore, at least partly, due to face awareness.

Effects of direct and averted gaze on the subsequent saccadic response.

The saccadic latency to visual targets is susceptible to the properties of the currently fixated objects. For example, the disappearance of a fixation stimulus prior to presentation of a peripheral target shortens saccadic latencies (the gap effect). In the present study, we investigated the influences of a social signal from a facial fixation stimulus (i.e., gaze direction) on subsequent saccadic responses in the gap paradigm. In Experiment 1, a cartoon face with a direct or averted gaze was used as a fixation stimulus. The pupils of the face were unchanged (overlap), disappeared (gap), or were translated vertically to make or break eye contact (gaze shift). Participants were required to make a saccade toward a target to the left or the right of the fixation stimulus as quickly as possible. The results showed that the gaze direction influenced saccadic latencies only in the gaze shift condition, but not in the gap or overlap condition; the direct-to-averted gaze shift (i.e., breaking eye contact) yielded shorter saccadic latencies than did the averted-to-direct gaze shift (i.e., making eye contact). Further experiments revealed that this effect was eye contact specific (Exp. 2) and that the appearance of an eye gaze immediately before the saccade initiation also influenced the saccadic latency, depending on the gaze direction (Exp. 3). These results suggest that the latency of target-elicited saccades can be modulated not only by physical changes of the fixation stimulus, as has been seen in the conventional gap effect, but also by a social signal from the attended fixation stimulus.

Influence of removal of invisible fixation on the saccadic and manual gap effect.

Saccadic and manual reactions to a peripherally presented target are facilitated by removing a central fixation stimulus shortly before a target onset (the gap effect). The present study examined the effects of removal of a visible and invisible fixation point on the saccadic gap effect and the manual gap effect. Participants were required to fixate a central fixation point and respond to a peripherally presented target as quickly and accurately as possible by making a saccade (Experiment 1) or pressing a corresponding key (Experiment 2). The fixation point was dichoptically presented, and visibility was manipulated by using binocular rivalry and continuous flash suppression technique. In both saccade and key-press tasks, removing the visible fixation strongly quickened the responses. Furthermore, the invisible fixation, which remained on the display but suppressed, significantly delayed the saccadic response. Contrarily, the invisible fixation had no effect on the manual task. These results indicate that partially different processes mediate the saccadic gap effect and the manual gap effect. In particular, unconscious processes might modulate an oculomotor-specific component of the saccadic gap effect, presumably via subcortical mechanisms.