Potential factors contributing to observed sex differences in virtual-reality-induced sickness.

Virtual reality (VR) technology has been widely adopted for several professional and recreational applications. Despite rapid innovation in hardware and software, one of the long prevailing issues for end users of VR is the experience of VR sickness. Females experience stronger VR sickness compared to males, and previous research has linked susceptibility to VR sickness to the menstrual cycle (Munafo et al., Exp Brain Res 235(3):889-901). Here we investigated the female versus male experience in VR sickness while playing an immersive VR game, comparing days of the menstrual cycle when hormones peak: day 15 (ovulation-peak estrogen) and day 22 (mid-luteal phase-peak progesterone). We found that immersion duration was greater in the second session than the first, and discomfort was lessened, suggesting a powerful adaptation with repeated exposure. Due to the estrogen levels changing along with the exposure, there was no clear independent impact of that; note, though, that there was a significant difference between self-report and physiological measures implying that GSR is potentially an unreliable measure of motion sickness. Although prior work found a delay over 2 days between session would not allow adaptation and habituation to reduce VR sickness susceptibility, we found that a week delay has potential success.

The Role of Sexual and Romantic Attraction in Human Mate Preferences.

Sex differences in mate preferences are ubiquitous, having been evidenced across generations and cultures. Their prevalence and persistence have compellingly placed them in the evolutionarily adaptive context of sexual selection. However, the psycho-biological mechanisms contributing to their generation and maintenance remain poorly understood. As such a mechanism, sexual attraction is assumed to guide interest, desire, and the affinity toward specific partner features. However, whether sexual attraction can indeed explain sex differences in partner preferences has not been explicitly tested. To better understand how sex and sexual attraction shape mate preferences in humans we assessed how partner preferences differed across the spectrum of sexual attraction in a sample of 479 individuals that identified as asexual, gray-sexual, demisexual or allosexual. We further tested whether romantic attraction predicted preference profiles better than sexual attraction. Our results show that sexual attraction accounts for highly replicable sex differences in mate preferences for high social status and financial prospects, conscientiousness, and intelligence; however, it does not account for the enhanced preference for physical attractiveness expressed by men, which persists even in individuals with low sexual attraction. Instead, sex differences in physical attractiveness preference are better explained by the degree of romantic attraction. Furthermore, effects of sexual attraction on sex differences in partner preferences were grounded in current rather than previous experiences of sexual attraction. Taken together, the results support the idea that contemporary sex differences in partner preferences are maintained by several psycho-biological mechanisms that evolved in conjunction, including not only sexual but also romantic attraction.

Self as a prior: The malleability of Bayesian multisensory integration to social salience.

Our everyday perceptual experiences are grounded in the integration of information within and across our senses. Due to this direct behavioural relevance, cross-modal integration retains a certain degree of contextual flexibility, even to social relevance. However, how social relevance modulates cross-modal integration remains unclear. To investigate possible mechanisms, Experiment 1 tested the principles of audio-visual integration for numerosity estimation by deriving a Bayesian optimal observer model with perceptual prior from empirical data to explain perceptual biases. Such perceptual priors may shift towards locations of high salience in the stimulus space. Our results showed that the tendency to over- or underestimate numerosity, expressed in the frequency and strength of fission and fusion illusions, depended on the actual event numerosity. Experiment 2 replicated the effects of social relevance on multisensory integration from Scheller & Sui, 2022 JEP:HPP, using a lower number of events, thereby favouring the opposite illusion through enhanced influences of the prior. In line with the idea that the self acts like a prior, the more frequently observed illusion (more malleable to prior influences) was modulated by self-relevance. Our findings suggest that the self can influence perception by acting like a prior in cue integration, biasing perceptual estimates towards areas of high self-relevance.

Correctly establishing evidence for cue combination via gains in sensory precision: Why the choice of comparator matters.

Studying how sensory signals from different sources (sensory cues) are integrated within or across multiple senses allows us to better understand the perceptual computations that lie at the foundation of adaptive behaviour. As such, determining the presence of precision gains - the classic hallmark of cue combination - is important for characterising perceptual systems, their development and functioning in clinical conditions. However, empirically measuring precision gains to distinguish cue combination from alternative perceptual strategies requires careful methodological considerations. Here, we note that the majority of existing studies that tested for cue combination either omitted this important contrast, or used an analysis approach that, unknowingly, strongly inflated false positives. Using simulations, we demonstrate that this approach enhances the chances of finding significant cue combination effects in up to 100% of cases, even when cues are not combined. We establish how this error arises when the wrong cue comparator is chosen and recommend an alternative analysis that is easy to implement but has only been adopted by relatively few studies. By comparing combined-cue perceptual precision with the best single-cue precision, determined for each observer individually rather than at the group level, researchers can enhance the credibility of their reported effects. We also note that testing for deviations from optimal predictions alone is not sufficient to ascertain whether cues are combined. Taken together, to correctly test for perceptual precision gains, we advocate for a careful comparator selection and task design to ensure that cue combination is tested with maximum power, while reducing the inflation of false positives.

The power of the self: Anchoring information processing across contexts.

A stable self-representation has an intrinsically beneficial connotation for information processing: it allows the individual to flexibly adapt to different contexts, while prioritizing information that pertains to the own immediate survival. Indeed, many studies have shown how linking arbitrary information to physical or psychological aspects of the self leads to pervasive effects on our decision-making and even our perception. However, the evidence we have gained so far stems from isolated aspects of the self, and varying measures across studies and different levels of processing make results difficult to compare. The present study demonstrates that associating arbitrary information with the self rapidly leads to faster and more efficient processing of information, with stable performance benefits across different tasks (matching and categorization task) and stimulus domains. Focusing on specific processing levels, the findings first provide evidence regarding the involvement of self-relatedness in perception. Here, contrast processing interacted with self-relatedness, but only when complex stimuli were used. Second, they show that self-prioritization is flexible to decisional modulations, with processing benefits being adjusted to different social contexts. Third, the present data provides evidence that performance benefits toward newly self-associated, abstract information are equivalent to those resulting from long-term established self-associations with personally owned objects. The results highlight mechanistic differences between the prioritization of information linked to the self and information linked to close others. Overall, the present findings suggest that the self acts as a stable anchor in information processing, allowing us to filter information by its immediate relevance to facilitate optimal behavior. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Social relevance modulates multisensory integration.

When interacting with the environment, humans exhibit robust biases toward information that pertains to themselves: Self-relevant information is processed faster and yields more accurate responses than information linked to others. Recent studies have shown that simple social associations can lead to the instant deployment of this benefit in the processing of abstract stimuli. However, how self-prioritization evolves across the processing hierarchy has been a subject of intense debate. Furthermore, there is little empirical evidence about the functional efficiency of social relevance in natural environments in which information is present across multiple senses. Across three experiments (each n = 40), the present study shows that self-prioritization effects (a) can arise in simple audio-visual numerosity judgements, (b) can be efficiently deployed across the senses by funneling perception toward self-relevant information in the more reliable sensory modality, and (c) modulate the integration of auditory and visual information into a multisensory representation. Taken together, the present findings suggest that social relevance can influence multisensory processing at both perceptual and postperceptual stages via early attentional modulations of sensory integration and later, task-dependent attentional control. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The Role of Vision in the Emergence of Mate Preferences.

Cross-cultural research has repeatedly demonstrated sex differences in the importance of partner characteristics when choosing a mate. Men typically report higher preferences for younger, more physically attractive women, while women typically place more importance on a partner's status and wealth. As the assessment of such partner characteristics often relies on visual cues, this raises the question whether visual experience is necessary for sex-specific mate preferences to develop. To shed more light onto the emergence of sex differences in mate choice, the current study assessed how preferences for attractiveness, resources, and personality factors differ between sighted and blind individuals using an online questionnaire. We further investigate the role of social factors and sensory cue selection in these sex differences. Our sample consisted of 94 sighted and blind participants with different ages of blindness onset: 19 blind/28 sighted males and 19 blind/28 sighted females. Results replicated well-documented findings in the sighted, with men placing more importance on physical attractiveness and women placing more importance on status and resources. However, while physical attractiveness was less important to blind men, blind women considered physical attractiveness as important as sighted women. The importance of a high status and likeable personality was not influenced by sightedness. Blind individuals considered auditory cues more important than visual cues, while sighted males showed the opposite pattern. Further, relationship status and indirect, social influences were related to preferences. Overall, our findings shed light on the availability of visual information for the emergence of sex differences in mate preference.

Late- but not early-onset blindness impairs the development of audio-haptic multisensory integration.

Integrating different senses to reduce sensory uncertainty and increase perceptual precision can have an important compensatory function for individuals with visual impairment and blindness. However, how visual impairment and blindness impact the development of optimal multisensory integration in the remaining senses is currently unknown. Here we first examined how audio-haptic integration develops and changes across the life span in 92 sighted (blindfolded) individuals between 7 and 70 years of age. We used a child-friendly task in which participants had to discriminate different object sizes by touching them and/or listening to them. We assessed whether audio-haptic performance resulted in a reduction of perceptual uncertainty compared to auditory-only and haptic-only performance as predicted by maximum-likelihood estimation model. We then compared how this ability develops in 28 children and adults with different levels of visual experience, focussing on low-vision individuals and blind individuals that lost their sight at different ages during development. Our results show that in sighted individuals, adult-like audio-haptic integration develops around 13-15 years of age, and remains stable until late adulthood. While early-blind individuals, even at the youngest ages, integrate audio-haptic information in an optimal fashion, late-blind individuals do not. Optimal integration in low-vision individuals follows a similar developmental trajectory as that of sighted individuals. These findings demonstrate that visual experience is not necessary for optimal audio-haptic integration to emerge, but that consistency of sensory information across development is key for the functional outcome of optimal multisensory integration.

Efficiency of Sensory Substitution Devices Alone and in Combination With Self-Motion for Spatial Navigation in Sighted and Visually Impaired.

Human adults can optimally combine vision with self-motion to facilitate navigation. In the absence of visual input (e.g., dark environments and visual impairments), sensory substitution devices (SSDs), such as The vOICe or BrainPort, which translate visual information into auditory or tactile information, could be used to increase navigation precision when integrated together or with self-motion. In Experiment 1, we compared and assessed together The vOICe and BrainPort in aerial maps task performed by a group of sighted participants. In Experiment 2, we examined whether sighted individuals and a group of visually impaired (VI) individuals could benefit from using The vOICe, with and without self-motion, to accurately navigate a three-dimensional (3D) environment. In both studies, 3D motion tracking data were used to determine the level of precision with which participants performed two different tasks (an egocentric and an allocentric task) and three different conditions (two unisensory conditions and one multisensory condition). In Experiment 1, we found no benefit of using the devices together. In Experiment 2, the sighted performance during The vOICe was almost as good as that for self-motion despite a short training period, although we found no benefit (reduction in variability) of using The vOICe and self-motion in combination compared to the two in isolation. In contrast, the group of VI participants did benefit from combining The vOICe and self-motion despite the low number of trials. Finally, while both groups became more accurate in their use of The vOICe with increased trials, only the VI group showed an increased level of accuracy in the combined condition. Our findings highlight how exploiting non-visual multisensory integration to develop new assistive technologies could be key to help blind and VI persons, especially due to their difficulty in attaining allocentric information.

Active touch facilitates object size perception in children but not adults: A multisensory event related potential study.

In order to increase perceptual precision the adult brain dynamically combines redundant information from different senses depending on their reliability. During object size estimation, for example, visual, auditory and haptic information can be integrated to increase the precision of the final size estimate. Young children, however, do not integrate sensory information optimally and instead rely on active touch. Whether this early haptic dominance is reflected in age-related differences in neural mechanisms and whether it is driven by changes in bottom-up perceptual or top-down attentional processes has not yet been investigated. Here, we recorded event-related-potentials from a group of adults and children aged 5-7 years during an object size perception task using auditory, visual and haptic information. Multisensory information was presented either congruently (conveying the same information) or incongruently (conflicting information). No behavioral responses were required from participants. When haptic size information was available via actively tapping the objects, response amplitudes in the mid-parietal area were significantly reduced by information congruency in children but not in adults between 190 ms-250 ms and 310 ms-370 ms. These findings indicate that during object size perception only children's brain activity is modulated by active touch supporting a neural maturational shift from sensory dominance in early childhood to optimal multisensory benefit in adulthood.

Effects can precede their cause in the sense of agency.

The sense of agency, i.e., the feeling that one׳s action is the cause of an external sensory event, involves causal inference based on the predicted sensory outcome of a motor act. Here, we investigated whether this inference process faithfully implements the physical principle that a cause (motor act) temporally precedes its effect (external sensory feedback). To this end, we presented participants with visual flashes that were temporally offset from voluntary button presses, including scenarios where the flash occurred shortly before the press. Participants then judged their experience of agency. As expected, cause-effect order is an important cue for this task: participants were far more likely to report agency for temporally lagging flashes than for leading flashes, even if very long sensory delays also disrupted the sense of agency (Experiment 1). This suggests that the temporal order between action and sensation is the dominant temporal cue for agency. However, when participants judged whether they had caused a first flash that occurred before the button press or a second flash that occurred afterwards, the temporal threshold for rejecting leading first flashes was relaxed proportionally to the delay of the second flash (Experiment 2). There was competition between different sensorimotor timing cues (temporal order favored the second flash and temporal proximity favored the first flash), and participants׳ tolerance for cause-effect inversions was modulated by the strength of the later, conflicting cue. We conclude that the perceived order of action and sensation is not used in a winner-take-all fashion in inference of agency. Instead, a probabilistic negotiation of the different timing cues favoring different flash events takes place postdictively, after presentation of the second flash.