The processing of faces under realistic virtual conditions engages distinct cognitive mechanisms that are attuned to their inherent conceptual and socially relevant characteristics. To more closely approximate real-life circumstances of personal encounters, the degree of realism is increased by situational context and further varied with respect to the stimuli's dimensionality and dynamics. To this end, a mobile-EEG study was conducted in which the participants encountered dynamic 3D virtual avatars and static 2D images of the avatars and were then asked to recognize their faces in a 2D old/new task, all within the same virtual environment. Stimulus processing during encoding and mnemonic mechanisms engaged during retrieval were investigated based on relevant event-related potentials (ERPs) as well as induced oscillatory responses. Although cognitive load did not differ between processing 2D and 3D faces, as indexed by comparable induced theta-band responses, recognition performance during retrieval showed that 3D faces were recognized more accurately. Investigation of the underlying cognitive processing revealed distinct recruitment of mnemonic mechanisms for the retrieval of 3D encoded faces, reflected in the face-specific frontal and centro-parietal ERP old/new effects (N400f, P600f) and characteristic responses in the induced theta and alpha bands. Specifically, the reactivation of the 3D face representations was characterized by concurrent identity-related and semantic recognition processing as well as increased attentional resource allocation. The realistic characteristics of the 3D faces, in terms of visual complexity and social quality, led to the formation of modality-specific engrams, which ultimately enabled better recognition of these faces than their 2D counterparts.

In psychophysiological research on memory encoding and retrieval, Virtual Reality (VR) allows for meaningful insights into mnemonic processing under realistic conditions, yet its effects on working memory (WM) processing and performance remain inconclusive. The present study investigates how information search processes in WM differ when stimulus material is encoded in a conventional monitor-based context or in a more realistic virtual setting, and whether complex, naturalistic stimulus properties facilitate or challenge WM processing and task performance. Participants performed a modified Sternberg task with everyday objects presented either on a 2D monitor or in photorealistic VR. To investigate the search mechanism and WM load, response times, accuracy, and parietal induced alpha activity during retention were analyzed. Across both modalities, response times, error rates, and parietal alpha activity increased with setsize, consistent with serial WM search up to capacity limits. Reaction times were faster for target than non-target probes, suggesting that complex object stimuli engage familiarity- or priming-based components in WM search, particularly in VR. Critically, 3D presentation yielded faster response times across setsizes and lower WM load, reflected by reduced parietal alpha activity during retention, while accuracy was preserved. Moreover, response times in the 2D condition deviated earlier from linearity at higher setsizes, whereas 3D presentation resulted in a more gradual increase, indicating delayed capacity-related saturation. Together, the behavioral and electrophysiological findings indicate that more realistic presentation in VR supports more efficient utilization of WM capacity, likely by facilitating access to stored representations, without altering the fundamental serial nature of WM search.

Traditional psychological laboratory research provides fundamental insights into the functioning of human recognition memory. However, concerns have been raised whether recognizing simplified two-dimensional (2D) laboratory stimuli accurately reflects real-world retrieval processes of their three-dimensional (3D) physical counterparts. To explore potential differences in mnemonic processing, we conducted a comparative study using a conventional recognition memory task after encoding objects on a 2D screen (PC) or in a physical replica of the experimental setup. Additionally, the encoding environment was recreated in virtual reality (VR) to further bridge the realism gap between physical reality and screen presentations. Within all conditions, behavioral results were complemented by memory-sensitive indices in the EEG (i.e., ERPs and oscillatory brain activity). Our results revealed overall high memory performance. Notably, the EEG indices indicated that different subprocesses contributed to successful recognition depending on the degree of realism. Specifically, while a parietal ERP old/new effect was observed across conditions, only the PC condition yielded a significant mid-frontal ERP old/new effect. Furthermore, the lower theta band response reliably marked successful recognition in all conditions, while the upper theta band response indicated more effortless recognition in the VR condition compared to the PC condition, with physical reality lying in between. Importantly, comparable alpha band responses across conditions suggest that these differences cannot be solely attributed to attentional resource allocation. Concludingly, this study provides evidence for modality-specific mnemonic processing characteristics as a function of realism. It advocates for the application of VR in psychological research to efficiently investigate lifelike cognitive processing.

Although recent psychological research provides evidence for enhanced memory retrieval of Virtual Reality (VR) experiences compared to conventional laboratory experiences, the functional characteristics of the underlying mnemonic processes remain unclear. Initial studies suggest that encoding and retrieval involve distinct cognitive processes, yet the possible technological artifacts induced by VR head-mounted displays (VR-HMDs) have not been accounted for. To determine the factors influencing modality-specific memory processing, 122 participants performed an old/new recognition memory task wearing a VR-HMD. Stimuli were first either presented two-dimensionally on a screen within a VR environment (mediated VR; mVR) or experienced immediately in a three-dimensional immersive VR environment (iVR). In the subsequent old/new recognition memory task, participants had to recall the stimuli either in the same or the other modality, providing a cross-modality comparison. As a result, the canonical context effect, i.e., an advantage for memory performance in congruent contexts, was found for both mVR and iVR modalities. Most importantly, the study further provides evidence for a memory superiority effect following iVR experiences, as an equally high retrieval success was observed even when the subsequent recall was tested in mVR. In conclusion, the improved recall observed suggests that immersive environments play a crucial role in enhancing the encoding process, whereas technological artifacts, particularly contextual factors of the VR-HMD, can be ruled out. Furthermore, the transferability of information from two-dimensional to three-dimensional environments seems limited. Our study thus advocates for integrating immersive VR into learning contexts to extend the applicability of learned content to various settings.

Characteristics of real-life objects, such as binocular depth, potentially yield visual processes going beyond what examinations of planar pictures as experimental cues can reveal. While virtual reality (VR) is used to approximate real-life features in experimental settings, this approach fundamentally hinges on whether the distinct modalities are processed in a similar way. To examine which stages of early visual processing depend on modality-specific characteristics, our study compares the electrophysiological responses to 2D (PC), VR, and real-life (RL) objects. To this end, participants passively explored abstract objects in one of these modalities followed by active exploration in a delayed matching-to-sample-task. Our results indicate that all modalities fundamentally yield comparable visual processes. Remarkably, our RL setup evoked the P1-N1-P2 complex corresponding to the well-established ERP morphology. However, the magnitude of the ERP response during real-life visual processing was more comparable to the response to VR than to PC. Indicating effects of stereoscopy on the earliest processing stages, the P1 differentiated only between PC and RL, and the N1 differentiated PC from both other conditions. In contrast, the P2 distinguished VR from both other conditions, which potentially indicated stereoscopic visual fatigue. Complementary analysis of the alpha-band response revealed higher attentional demands in response to PC and VR compared with RL, ruling out that the ERP-based results are exclusively driven by attentional effects. Whereas comparable fundamental processes are likely occurring under all modalities, our study advises the use of VR if the processes' magnitude is of relevance, emphasizing its value to approximate real-life visual processing.

Initial findings linking Virtual Reality (VR)-based encoding to increased recollection at retrieval remain inconclusive due to heterogeneous study designs and dependence on behavioral data. To clarify under which circumstances VR-based encoding affects or enhances episodic memory retrieval, the fundamental question remains whether the encoding modality, i.e., VR or 2D-desktops (PC), functions as a source for recollection, independent of further contextual factors. Specifically, the electrophysiological correlates (EEG) of item and source memory could objectively determine whether source retrieval fosters recollection and attenuates familiarity of VR-encoded information (i.e., VR-engrams) compared to PC-encoded information (i.e., PC-engrams).To this end, participants incidentally encoded everyday objects in VR and on a 2D desktop in a within-subjects design, followed by unannounced old/new and source identification tasks. Our results indicate that encoding modality affects item memory only to a limited degree: Recognition memory performance, alongside the electrophysiological markers of item memory, i.e., the frontal and parietal old/new effects (FN400, LPC) and the theta band response, yielded comparable results for both engrams. Yet source memory differs depending on the encoding modality: The late posterior negativity indicated a shift towards recollection regarding the retrieval of VR-engrams compared to PC-engrams. This shift might result from attenuated familiarity with VR-engrams, particularly reflected in the alpha band and phase-amplitude coupling of theta and gamma band. In conclusion, encoding modality functions to some degree as a relevant source for recognition memory. Yet our results propose that familiarity is more strongly affected than recollection if contextual information beyond dimensionality is matched between encoding modalities.

BackgroundCognitive biases, such as applying stricter body evaluation for oneself than for others, are presumed to promote the development and maintenance of eating disorders. While questionnaire data have demonstrated a familial transmission of body image, these self-deprecating double standards (DS) have not been studied among female adolescents, and a potential familial transmission of DS through feedback/role-modeling is yet to be explored. The present study thus addresses these questions.MethodsFemale adolescents and their mothers viewed pictures of their own and peer bodies presented with their own and another peer's face, and were asked to rate arousal, valence, body attractiveness, and body fat for each body.ResultsDaughters evaluated their own, an average-weight, and an overweight build as less attractive and with more body fat when presented with their own than with another face, while mothers mainly applied such self-deprecating DS for an overweight build. Regarding familial transmission, higher negative maternal feedback was associated with more self-deprecating DS of body fat and attractiveness in daughters when viewing an overweight build.ConclusionsFemale adolescents and their mothers apply self-deprecating DS, suggesting that DS are widespread. Psychoeducation and training regarding communication, feedback, and body functionality might support the prevention of DS.

Immersive virtual reality (iVR), that is, digital stereoscopic 360° scenarios usually presented in head-mounted displays, has gained much popularity in medical, educational, and consumer contexts in the last years. Recently, psychological research started to utilize the theoretical and methodological advantages of iVR. Furthermore, understanding cognitive, emotional, and behavioral processes in iVR similar to real-life is a genuinely psychological, currently understudied topic. This article briefly reviews the current application of iVR in psychological research and related disciplines. The review presents empirical evidence for opportunities and strengths (e.g., realism, experimental control, effectiveness of therapeutic and educational interventions) as well as challenges and weaknesses (e.g., differences in experiencing presence, interacting with VR content including avatars, i.e., graphical representation of a person). The main part discusses areas requiring additional basic research, such as cognitive processes, socio-emotional processes during social interactions in iVR, and possible societal implications (e.g., fraud, VR-addiction). For both research and application, iVR offers a contemporary extension of the psychological toolkit, offering new avenues to investigate and enhance core phenomena of psychology such as cognition, affect, motivation, and behavior. Still, it is crucial to exercise caution in its application as excessive and careless use of iVR can pose risks to individuals' mental and physical well-being.

Conventionally, event-related potential (ERP) analysis relies on the researcher to identify the sensors and time points where an effect is expected. However, this approach is prone to bias and may limit the ability to detect unexpected effects or to investigate the full range of the electroencephalography (EEG) signal. Data-driven approaches circumvent this limitation, however, the multiple comparison problem and the statistical correction thereof affect both the sensitivity and specificity of the analysis. In this study, we present SHERPA – a novel approach based on explainable artificial intelligence (XAI) designed to provide the researcher with a straightforward and objective method to find relevant latency ranges and electrodes. SHERPA is comprised of a convolutional neural network (CNN) for classifying the conditions of the experiment and SHapley Additive exPlanations (SHAP) as a post hoc explainer to identify the important temporal and spatial features. A classical EEG face perception experiment is employed to validate the approach by comparing it to the established researcher- and data-driven approaches. Likewise, SHERPA identified an occipital cluster close to the temporal coordinates for the N170 effect expected. Most importantly, SHERPA allows quantifying the relevance of an ERP for a psychological mechanism by calculating an ”importance score”. Hence, SHERPA suggests the presence of a negative selection process at the early and later stages of processing. In conclusion, our new method not only offers an analysis approach suitable in situations with limited prior knowledge of the effect in question but also an increased sensitivity capable of distinguishing neural processes with high precision.

While pictures share global similarities with the real-world objects they depict, the latter have unique characteristics going beyond 2D representations. Due to its three-dimensional presentation mode, Virtual Reality (VR) is increasingly used to further approach real-world visual processing, yet it remains unresolved to what extent VR yields process comparable to real-world processes. Consequently, our study examined visuospatial processing by a triangular comparison of 2D objects, virtual 3D objects and real 3D objects. The theta band response (TBR) was analysed as an electrophysiological correlate of visual processing, allowing for the differentiation of predominantly stimulus-driven processes mirrored in the evoked response and internal, complex processing reflected in the induced response. Our results indicate that the differences between conditions driven by sensory features go beyond a binary division into 2D and 3D materials but are based on further sensory features: The evoked posterior TBR differentiated between all conditions but revealed fewer differences between processing of real-world and VR objects. Moreover, the induced midfrontal TBR indicated higher cognitive load for 2D objects compared to VR and real-world objects, while no difference between both latter conditions was revealed. In conclusion, our results demonstrate that the transferability of 2D- and VR-based findings to real-world processes depends to some degree on whether predominantly sensory stimulus features or higher cognitive processes are examined. Yet although VR and real-world processes are not to be equated based on our results, their comparison yielded fewer significant differences relative to the PC condition, advising the use of VR to examine visuospatial processing.

In psychophysiological research, the use of Virtual Reality (VR) for stimulus presentation allows for the investigation of how perceptual processing adapts to varying degrees of realism. Previous time-domain studies have shown that perceptual processing involves modality-specific neural mechanisms, as evidenced by distinct stimulus-locked components. Analyzing induced oscillations across different frequency bands can provide further insights into neural processes that are not strictly phase-locked to stimulus onset. This study uses a simple perceptual paradigm presenting images of faces and cars on both a standard 2D monitor and in an immersive VR environment. To investigate potential modality-dependent differences in attention, cognitive load, and task-related post-movement processing, the induced alpha, theta and beta band responses are compared between the two modalities. No evidence was found for differences in stimulus-dependent attention or task-related post-movement processing between the 2D conditions and the realistic virtual conditions in electrode space, as posterior alpha suppression and re-synchronization of centro-parietal beta did not differ between conditions. However, source analysis revealed differences in the attention networks engaged during 2D and 3D perception. Midfrontal theta was significantly stronger in laboratory conditions, indicating higher cognitive load than in the VR environment. Exploratory analysis of posterior theta showed stronger responses in VR, possibly reflecting the processing of depth information provided only by the 3D material. In addition, the theta response seems to be generated by distinct neuronal sources under realistic virtual conditions indicating enhanced involvement of semantic information processing and social cognition.

In the human electroencephalogram (EEG), induced oscillatory responses in various frequency bands are regarded as valuable indices to examine the neural mechanisms underlying human memory. While the advent of virtual reality (VR) drives the investigation of mnemonic processing under more lifelike settings, the joint application of VR and EEG methods is still in its infancy (e.g., due to technical limitations impeding the signal acquisition). The objective of the present EEG study was twofold. First, we examined whether the investigation of induced oscillations under VR conditions yields equivalent results compared to standard paradigms. Second, we aimed at obtaining further insights into basic memory-related brain mechanisms in VR. To these ends, we relied on a standard implicit memory design, namely repetition priming, for which the to-be-expected effects are well-documented for conventional studies. Congruently, we replicated a suppression of the evoked potential after stimulus onset. Regarding the induced responses, we observed a modulation of induced alphaband in response to a repeated stimulus. Importantly, our results revealed a repetition-related suppression of the high-frequency induced gammaband response (>30 Hz), indicating the sharpening of a cortical object representation fostering behavioral priming effects. Noteworthy, the analysis of the induced gammaband responses required a number of measures to minimize the influence of external and internal sources of artefacts (i.e., the electrical shielding of the technical equipment and the control for miniature eye movements). In conclusion, joint VR–EEG studies with a particular focus on induced oscillatory responses offer a promising advanced understanding of mnemonic processing under lifelike conditions.

Human face perception is a specialized visual process with inherent social significance. The neural mechanisms reflecting this intricate cognitive process have evolved in spatially complex and emotionally rich environments. Previous research using VR to transfer an established face perception paradigm to realistic conditions has shown that the functional properties of face-sensitive neural correlates typically observed in the laboratory are attenuated outside the original modality. The present study builds on these results by comparing the perception of persons and objects under conventional laboratory (PC) and realistic conditions in VR. Adhering to established paradigms, the PC- and VR modalities both featured images of persons and cars alongside standard control images. To investigate the individual stages of realistic face processing, response times, the typical face-sensitive N170 component, and relevant subsequent components (L1, L2; pre-, post-response) were analyzed within and between modalities. The between-modality comparison of response times and component latencies revealed generally faster processing under realistic conditions. However, the obtained N170 latency and amplitude differences showed reduced discriminative capacity under realistic conditions during this early stage. These findings suggest that the effects commonly observed in the lab are specific to monitor-based presentations. Analyses of later and response-locked components showed specific neural mechanisms for identification and evaluation are employed when perceiving the stimuli under realistic conditions, reflected in discernible amplitude differences in response to faces and objects beyond the basic perceptual features. Conversely, the results do not provide evidence for comparable stimulus-specific perceptual processing pathways when viewing pictures of the stimuli under conventional laboratory conditions.

Virtual reality (VR) has become a popular tool for investigating human behavior and brain functions. Nevertheless, it is unclear whether VR constitutes an actual form of reality or is more like an advanced simulation. Determining the nature of VR has been mostly achieved by self-reported presence measurements, defined as the feeling of being submerged in the experience. However, subjective measurements might be prone to bias and, most importantly, do not allow for a comparison with real-life experiences. Here, we show that real-life and VR height exposures using 3D-360° videos are mostly indistinguishable on a psychophysiological level (EEG and HRV), while both differ from a conventional 2D laboratory setting. Using a fire truck, three groups of participants experienced a real-life (N = 25), a virtual (N = 24), or a 2D laboratory (N = 25) height exposure. Behavioral and psychophysiological results suggest that identical exogenous and endogenous cognitive as well as emotional mechanisms are deployed to process the real-life and virtual experience. Specifically, alpha- and theta-band oscillations in line with heart rate variability, indexing vigilance, and anxiety were barely indistinguishable between those two conditions, while they differed significantly from the laboratory setup. Sensory processing, as reflected by beta-band oscillations, exhibits a different pattern for all conditions, indicating further room for improving VR on a haptic level. In conclusion, the study shows that contemporary photorealistic VR setups are technologically capable of mimicking reality, thus paving the way for the investigation of real-world cognitive and emotional processes under controlled laboratory conditions. For a video summary, see https://youtu.be/fPIrIajpfiA.

Acupressure mats are promoted as stress management tools for easy and effective self-application, promising reduced stress and increased well-being. However, the scientific evidence for these effects is based on few experimental studies and lacks the examination of acupressure mats as a solitary relaxation tool. Our study aimed to examine which changes in stress and well-being can be expected from the use of acupressure mats by healthy young people on the subjective and psychophysiological level. Unexperienced participants practiced relaxation for three weeks either with an acupressure mat or without any tools (active control group [CG]). As a results, subjective well-being and stress decreased, while sleep quality and concentration endurance increased across groups. Blood pressure (BP), heart rate (HR), pain threshold and pain tolerance did not change significantly from pre- to post-training measurements. Most importantly, no significant differences were found between groups, indicating that training with an acupressure mat yielded no superior effects compared with an active control condition in healthy young students. As a conclusion, taking time to relax has some but limited beneficial effects on the subjective levels independent of the specific method for healthy students. Potential beneficial effects of acupressure mats might be bound to specific impairments, such as tension pain.

Although the human brain is adapted to function within three-dimensional environments, conventional laboratory research commonly investigates cognitive mechanisms in a reductionist approach using two-dimensional stimuli. However, findings regarding mnemonic processes indicate that realistic experiences in Virtual Reality (VR) are stored in richer and more intertwined engrams than those obtained from the conventional laboratory. Our study aimed to further investigate the generalizability of laboratory findings and to differentiate whether the processes underlying memory formation differ between VR and the conventional laboratory already in early encoding stages. Therefore, we investigated the Repetition Suppression (RS) effect as a correlate of the earliest instance of mnemonic processes under conventional laboratory conditions and in a realistic virtual environment. Analyses of event-related potentials (ERPs) indicate that the ERP deflections at several electrode clusters were lower in VR compared to the PC condition. These results indicate an optimized distribution of cognitive resources in realistic contexts. The typical RS effect was replicated under both conditions at most electrode clusters for a late time window. Additionally, a specific RS effect was found in VR at anterior electrodes for a later time window, indicating more extensive encoding processes in VR compared to the laboratory. Specifically, electrotomographic results (VARETA) indicate multimodal integration involving a broad cortical network and higher cognitive processes during the encoding of realistic objects. Our data suggest that object perception under realistic conditions, in contrast to the conventional laboratory, requires multisensory integration involving an interconnected functional system, facilitating the formation of intertwined memory traces in realistic environments.

The perception of faces is one of the most specialized visual processes in the human brain and has been investigated by means of the early event-related potential component N170. However, face perception has mostly been studied in the conventional laboratory, i.e., monitor setups, offering rather distal presentation of faces as planar 2D-images. Increasing spatial proximity through Virtual Reality (VR) allows to present 3D, real-life-sized persons at personal distance to participants, thus creating a feeling of social involvement and adding a self-relevant value to the presented faces. The present study compared the perception of persons under conventional laboratory conditions (PC) with realistic conditions in VR. Paralleling standard designs, pictures of unknown persons and standard control images were presented in a PC- and a VR-modality. To investigate how the mechanisms of face perception differ under realistic conditions from those under conventional laboratory conditions, the typical face-specific N170 and subsequent components were analyzed in both modalities. Consistent with previous laboratory research, the N170 lost discriminatory power when translated to realistic conditions, as it only discriminated faces and controls under laboratory conditions. Most interestingly, analysis of the later component [230–420 ms] revealed more differentiated face-specific processing in VR, as indicated by distinctive, stimulus-specific topographies. Complemented by source analysis, the results on later latencies show that face-specific neural mechanisms are applied only under realistic conditions (A video abstract is available in the Supplementary material and via YouTube: https://youtu.be/TF8wiPUrpSY).