{"id":"fd88e3b7-42ea-49ed-9e7e-b143f45549ea","arxiv_id":"2607.06901","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":3.0,"correctness_risk":"unknown","formal_verification":"none","parameter_count":0,"one_line_summary":"A position paper proposing that cross-sensory interactions, not just additive sensory inputs, should guide the design of restorative virtual reality nature environments.","lead":"This paper argues that multisensory virtual reality nature environments should be studied through cross-sensory interactions rather than as additive sensory inputs. It outlines a research agenda for how mismatched audio, visual, scent, and touch elements in VR nature scenes may affect stress reduction and attention restoration.","discovery_kind":"unclear","skeptic_critique":{"model":"glm-5.2","headline":"The paper's core distinction between 'additive' and 'cross-sensory' interactions is never operationally defined, leaving the central claim unfalsifiable as stated.","rationale":"The reader correctly identified that the paper's central premise (cross-sensory interactions differ from additive effects) rests on indirect observations without direct evidence. I sharpen this to the more fundamental issue: the paper never defines what would distinguish a cross-sensory interaction from an additive effect, so even future studies following the proposed agenda would not know whether they had found one. This is the load-bearing concern because the entire value proposition of the paper — that current additive frameworks are insufficient and cross-sensory research is 'essential' — depends on this distinction being meaningful and detectable. The verdict remains CONDITIONAL because this is a position paper, and the concern is about conceptual precision rather than data fabrication or logical inconsistency. The paper is honest about its status as a call for future work, and the research directions proposed in §4.1–4.3 are reasonable. But the conceptual gap means the paper's contribution is more of an open question than a framework — it identifies that something might be missing without specifying what that something would look like. A reader should know that the proposed agenda cannot yet be evaluated for whether it would actually test the distinction it claims to prioritize.","tokens_in":6120,"tokens_out":1105,"duration_ms":55719,"concrete_test":"Construct a 2×2 factorial design (e.g., visual wind present/absent × audio wind present/absent) and pre-register a statistical criterion for interaction: if the effect of audio on stress reduction differs significantly depending on visual condition (i.e., a significant interaction term in a factorial ANOVA), this constitutes cross-sensory interaction; if effects are independent and sum linearly, they are additive. If no such criterion can be specified, the additive-vs-cross-sensory distinction lacks empirical traction.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper's central claim is that cross-sensory interactions in VNEs are qualitatively different from additive sensory effects and that this distinction matters for designing restorative environments. However, the paper never provides an operational definition of what constitutes a 'cross-sensory interaction' versus an 'additive effect.' The examples given — rustling sounds feeling threatening (§4.1), air vent breeze enhancing visuals (§4.3) — are consistent with both additive accounts (the sound adds a threat cue, the breeze adds a presence cue) and interaction accounts (the sound changes visual perception). Without a clear criterion for what would distinguish an interaction effect from an additive one, the proposed research agenda (§4.1–4.3) cannot be evaluated for whether it would actually test the distinction. The paper cites Song et al. [24] as focusing on 'additive effects' and a systematic review [8] calling for cross-sensory frameworks, but neither reference provides the missing definition. For a position paper whose entire value rests on the claim that current additive frameworks are insufficient, the absence of a conceptual boundary between 'additive' and 'cross-sensory' is the weakest link. This is not a demand for empirical data — position papers need not have experiments — but the conceptual scaffolding should at least specify what would count as a cross-sensory interaction.","agreement_with_reader":"agree"},"referee_report":{"model":"glm-5.2","summary":"This position paper argues that cross-sensory interactions in virtual reality nature environments (VNEs) are underexplored and that future research should move beyond treating senses as merely additive. The authors review current multisensory VNE research (Section 2), focusing on audio, visual, scent, and touch components, and propose future research avenues for studying cross-sensory interactions across these modalities (Section 4). The manuscript is framed as a call to action for the VNE research community to investigate how interactions between senses—rather than isolated sensory additions—affect stress reduction and attention restoration.","tokens_in":6291,"tokens_out":1036,"duration_ms":103733,"significance":"The manuscript identifies a genuine gap in the VNE literature: while multisensory environments are increasingly studied, the interaction effects between senses (as opposed to additive effects) have received little systematic attention. The proposed research directions in Section 4 are concrete and actionable, including specific experimental designs for audio-visual matching (§4.1), scent congruence (§4.2), and wind/temperature manipulation (§4.3). The observation that participants spontaneously reported air vent breezes enhancing visual nature perception (§4.3, citing [20]) is a useful empirical anchor. The relevance to applied settings (hospitals, nursing homes, PTSD treatment) is well-motivated.","major_comments":[{"comment":"The central distinction between 'additive' and 'cross-sensory' interactions is never operationally defined. The abstract, Section 3, and Section 4 all rest on the claim that current frameworks treat senses as additive while cross-sensory interactions are qualitatively different and more complex. However, the manuscript provides no conceptual criterion for what would distinguish an additive effect from a cross-sensory interaction. The examples given—rustling sounds feeling threatening when mismatched to visuals (§4.1) and air vent breezes enhancing visuals (§4.3)—are each consistent with both an additive account (the sound adds a threat cue; the breeze adds a presence cue) and an interaction account (the sound changes visual perception). Without specifying what would count as a cross-sensory interaction versus an additive combination, the proposed research agenda in §4.1–4.3 cannot beeval","section":null},{"comment":"Section 4.1 proposes testing 'specific audio and visual components that match or do not match' to study how sounds or visuals can seem intimidating when inappropriately matched. However, the manuscript does not define what constitutes a 'match' or 'mismatch' between audio and visual components, nor does it specify how the resulting data would distinguish cross-sensory interaction from simple congruence effects already well-documented in multisensory perception literature. The position would be strengthened by engaging with existing cross-modal correspondence research (e.g., Spence, 2011) and specifying how the proposed VNE studies would go beyond established congruence paradigms.","section":null},{"comment":"The claim in Section 2 that 'certain results from the current literature may indicate that there are more complex, cross-sensory interactions occurring' is supported by only one concrete example (threatening rustling sounds). The manuscript would benefit from a more systematic survey of existing results that are anomalous under additive accounts, as this would establish the empirical motivation for the cross-sensory framework more convincingly. As stated, the motivation rests on a single illustrative case.","section":null}],"minor_comments":[{"comment":"Section 4.2: The distinction between 'scents of things in nature' (e.g., burning a candle with eucalyptus oil) and 'scents of present natural items' (e.g., soil samples) is introduced but its relevance to cross-sensory interactions is not explained. Clarifying why this distinction matters for the proposed research would help.","section":null},{"comment":"Section 4.3: The anecdotal observation about air vents is attributed to 'past studies conducted by our research group' citing [20], but the manuscript does not describe the study design or sample size, making it difficult to assess the weight of this evidence. A brief description would strengthen the point.","section":null},{"comment":"The term 'forest bathing' is introduced in Section 1 without its Japanese origin (shinrin-yoku), which is standard context in this literature.","section":null},{"comment":"Reference [8] is cited as calling for multisensory research frameworks that approach cross-sensory interactions, but the manuscript does not describe what such a framework would look like or how the proposed research avenues in Section 4 would constitute one.","section":null}],"recommendation":"major_revision","confidential_remarks":"The paper is a reasonable position paper but reads more like an extended abstract or workshop proposal than a full journal article. The core conceptual contribution—the additive vs. cross-sensory distinction—needs formal development before the paper can serve as a useful agenda-setting piece. The authors may benefit from engaging with the broader multisensory integration literature (e.g., Stein & Meredith, 1993; Spence, 2011) where interaction vs. additive effects have been formally discussed for decades."},"author_rebuttal":null,"desk_editor":{"model":"glm-5.2","letter":"Short version: this is a well-organized position paper that identifies a real gap in multisensory VR nature environment (VNE) research and proposes a research agenda. It is not a research paper — no new data, no new methods, no formal derivations. The central claim is that cross-sensory interactions in VNEs are underexplored and may differ qualitatively from additive sensory effects. That is a reasonable thesis, but the paper does not do the conceptual work needed to make it actionable. Worth a serious referee as a workshop position paper or short communication, but not a full research contribution. The stress-test concern about the missing operational definition is the right thing to flag, and it does land. The paper repeatedly contrasts 'additive' with 'cross-sensory' interactions but never specifies what would distinguish them empirically. The rustling-sounds example (§4.1) is consistent with both accounts: the sound adds a threat cue (additive) or changes visual perception (interactive). The air vent anecdote (§4.3) has the same problem. Without a criterion for what counts as a cross-sensory interaction versus an additive effect, the proposed experiments in §4.1–4.3 cannot be evaluated for whether they would actually test the distinction. That said, the paper does some things right. The literature review is focused and honest about the state of the field. The authors correctly note that systematic reviews (refs [8], [15]) have already called for cross-sensory frameworks, which means they are not overclaiming novelty. The research directions in §4 are concrete enough to be useful starting points — the scent-matching and wind-temperature proposals are reasonable experimental designs. The self-citations ([19], [20], [21]) support the motivation without circular reasoning. The reader's scores look fair to me. Novelty at 3.0 is about right — the cross-sensory observation is well established in perceptual psychology, and the application to VNEs is incremental. Soundness at 4.0 is generous but defensible for a position paper with no formal claims to validate. The significance-conditional-on-future-work framing is accurate. This paper is for VNE researchers and HCI groups working on therapeutic VR who want a roadmap for multisensory experiments. It would benefit from a paragraph defining what operational criterion would separate additive from interactive effects — even a conceptual one. Without that, the agenda is suggestive but not yet rigorous. I would send it to a serious referee at a venue that accepts position papers, with the expectation that the reviewers push hard on the definitional gap.","headline":"Position paper calling for cross-sensory (not merely additive) research in VR nature environments; clearly written but conceptually underspecified","tokens_in":6998,"tokens_out":605,"would_cite":false,"duration_ms":121260,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"glm-5.2","headline":"When senses collide in VR nature, they may heal or harm","keywords":[],"falsifier":"A controlled experiment showing that the stress-reduction effect of adding a second or third sensory channel to a VR nature scene is fully predicted by the sum of each channel's individual effect, with no residual variance attributable to their combination, would refute the paper's central distinction.","tokens_in":6375,"feed_emoji":"🌲","tokens_out":1022,"duration_ms":121552,"temperature":0.7,"pith_summary":"This paper argues that the standard approach to building restorative virtual nature environments — adding one sense at a time on top of visuals — misses something fundamental. The authors contend that senses do not simply stack additively in virtual reality nature scenes; they interact. A sound that fits the scene can deepen relaxation, but the same type of sound placed in the wrong visual context can feel threatening and undermine the restorative goal. The paper calls for a research program that systematically studies how audio, visuals, smell, and touch influence each other's perception, rather than studying each sense in isolation. The central object carrying the argument is the cross-sensory interaction: the way one sensory channel changes the meaning and emotional valence of another. The authors propose specific experimental designs — matching and mismatching audio with visuals, introducing scents that do or do not fit the scene, and manipulating wind and temperature alongside visual content — to map these interactions. If the authors are right, the difference between a stress-reducing virtual forest and a stress-inducing one lies not in any single sensory channel but in the congruence or conflict among them.","feed_headline":"VR nature's healing power may depend on sensory congruence, not addition","feed_subtitle":"When sounds, scents, and touches clash with visuals in virtual forests, stress reduction can reverse. Designers need to study how senses交互,","key_machinery":"The argument turns on a distinction between two models of multisensory combination. The additive model treats each sense as contributing an independent positive effect: add a pleasant sound, get more relaxation; add a pleasant scent, get more still. The cross-sensory model says the effect of adding a sense depends on its fit with the other senses already present — a sound that is relaxing in one visual context can be anxiety-inducing in another. The authors propose that congruence — the degree to which a sensory input matches the expectations set by the other channels — is the variable that determines whether a multisensory addition increases or decreases stress reduction. They suggest this:","core_discovery":"The paper's central claim is that cross-sensory interactions in virtual nature environments are qualitatively distinct from additive sensory effects and must be studied directly to design environments that actually reduce stress. The authors identify the congruence between sensory channels — whether a sound, smell, or tactile sensation fits the visual scene — as the mechanism that determines whether an added sense helps or harms the restorative experience. They do not present new experimental data; instead they reframe existing observations (rustling sounds feeling threatening when mismatched to visuals, unexpected air-breeze feedback enhancing immersion) as evidence that the field's current","pith_inferences":["If cross-sensory congruence is the key variable, then there should be an optimal level of sensory richness: too few senses and congruence is trivial; too many and the probability of mismatch rises. This predicts an inverted-U relationship between sensory channel count and stress reduction.","The congruence mechanism might extend to memory and learning VR environments, not just restorative ones — a mismatched soundtrack in an educational VR simulation could impair retention by triggering low-level threat vigilance.","If the effect is driven by expectation violation rather than sensory conflict per se, then novel or unfamiliar nature scenes might be more tolerant of sensory mismatch than familiar ones, because users have weaker prior expectations to violate."],"forward_implications":["Designers of VR nature environments for clinical use (hospitals, nursing homes, PTSD treatment) would need to test sensory congruence systematically, not just add pleasant stimuli.","A mismatched sensory channel could actively harm vulnerable users — e.g., a threatening sound in a therapeutic VR forest could raise stress rather than lower it in a PTSD patient.","Scent technology design for VR would need to prioritize temporal and semantic matching with the audio-visual scene, not just pleasantness of the scent itself.","Restorative VR research would shift from asking 'which senses should we include?' to asking 'which combinations of senses produce congruence, and which produce conflict?'"],"fun_headline_variants":["Cross-sensory VR nature design may beat adding senses one by one","Mismatched sounds and scents can reverse VR nature's stress reduction","Sensory congruence in virtual forests may matter more than sensory count","Cross-sensory interactions in VR nature are underexplored, review finds","Incongruent sensory cues in virtual forests may undermine restoration"],"cache_read_input_tokens":0,"weakest_assumption_plain":"The paper assumes that cross-sensory interactions are qualitatively different from additive sensory effects, but supports this only with indirect observations — anecdotal participant comments about air vents and the intuitive example of rustling sounds feeling threatening — rather than controlled experiments that isolate interaction effects from simple addition.","fun_headline_variants_meta":{"raw":{"variants":["Cross-sensory VR nature design may beat adding senses one by one","Mismatched sounds and scents can reverse VR nature's stress reduction","Sensory congruence in virtual forests may matter more than sensory count","Cross-sensory interactions in VR nature are underexplored, review finds","Incongruent sensory cues in virtual forests may undermine restoration"]},"model":"glm-5.2","effort":"low","cost_usd":0.0,"raw_usage":{"total_tokens":591,"prompt_tokens":513,"completion_tokens":78,"prompt_tokens_details":null},"tokens_in":513,"tokens_out":78,"duration_ms":31428,"temperature":1.0,"reasoning_tokens":null,"cache_read_input_tokens":0,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-09T23:14:09.023388+00:00","model_set":{"reader":"glm-5.2"},"falsifier":"A controlled experiment showing that the stress-reduction effect of adding a second or third sensory channel to a VR nature scene is fully predicted by the sum of each channel's individual effect, with no residual variance attributable to their combination, would refute the paper's central distinction.","supporting_citations":[],"review_version":1}