What Removing the Overlay Reveals About the System It Covers¶

An Open-Source Framework for Consciousness, Psychedelic, and Therapeutic Research¶

The Short Version¶

About 1% of people have no visual imagination whatsoever. They can't picture a beach, replay a memory as a movie, or hear a song in their head. This is called aphantasia, and it was only named in 2015.

The standard interpretation treats this as a deficit — something missing. We propose a different framing: these individuals aren't running on a different system. They're running on the same system as everyone else — with the rendering overlay removed. The interoceptive-somatic substrate that produces gut feelings, body-based evaluation, emotional processing, and contemplative states operates in every mammalian brain. In typical imagers, it's obscured by the imagery overlay that dominates conscious report — the way stars are invisible in daylight, not absent. In complete aphantasia, the overlay is gone. The substrate becomes visible.

This is the same principle as albinism: removing pigmentation doesn't reveal a different skin system — it reveals the melanin synthesis pathway that exists in all skin but is normally hidden.

This reframing has immediate practical consequences for psychedelic research, trauma therapy, meditation science, education, and our understanding of what mystical experience actually is — and not just for the 1%. The body-based substrate that aphantasia makes visible turns out to be where the deepest therapeutic and contemplative work happens, for everyone.

The Core Idea¶

Your brain runs on an interoceptive-somatic substrate — an ancient network running from your gut, heart, and muscles through your brainstem and into your insular cortex. This system gives you body-based evaluations of situations ("gut feelings"), processes others' emotional states through physiological mirroring, and generates what Damasio calls "somatic markers" — body-state predictions that guide decision-making before you can articulate why. Craig's model proposes that the anterior insular cortex generates a progressive integration of these body signals that may be the neural substrate of subjective awareness itself.

Layered on top of this substrate, most brains run an imagery overlay — a simulation engine where the prefrontal cortex commandeers sensory cortices to generate internal movies, sounds, and sensations. This overlay is powerful, but it's also a relatively recent evolutionary addition. It doesn't replace the substrate. It covers it.

In typical imagers, the overlay dominates conscious report. When you have a gut feeling and you visualize the scenario, you report the visualization. The body signal that preceded it — that may have generated it — is attributed to the image rather than to the somatic marker that fired first. The overlay takes credit for the substrate's work.

In complete aphantasia, the overlay is absent. The substrate is experienced as what it is: body-based knowing, somatic evaluation, interoceptive processing without visual rendering. Not a different system. The same system, unobscured.

Recent empirical evidence strengthens this account. Monzel et al. (2025) demonstrated through structural equation modeling that the relationship between imagery vividness and mental health is mediated by interoceptive processing and alexithymia — the substrate pathway this framework identifies. Strikingly, core aphantasics (VVIQ = 16, complete absence) showed better mental health than hypophantasics (weak imagery), suggesting that complete overlay absence may allow cleaner substrate access than a degraded but still-interfering overlay.

Why This Matters Right Now¶

For psychedelic research¶

Psychedelic therapy is experiencing a clinical renaissance, with psilocybin showing remarkable results for depression, PTSD, and end-of-life anxiety. But a fundamental question remains unanswered: are the visual hallucinations the therapy, or just a side effect of the therapy?

The REBUS model (Carhart-Harris & Friston, 2019) proposes that psychedelics work by relaxing rigid beliefs at the substrate level — loosening the brain's overly confident predictions about itself and the world. The Default Mode Network, which maintains the narrative self, is suppressed. This enables revision of pathologically fixed self-models. Visual hallucinations, in this framework, are what happens when top-down predictions flood the overlay with the "volume knob ripped off."

If the overlay is architecturally absent — as in complete aphantasia — what happens? Stoliker et al. (2024) showed psilocybin produces visual imagery through enhanced top-down connectivity to visual cortex — the overlay mechanism. Siegel et al. (2024, Nature) showed it simultaneously causes global brain desynchronization correlated with mystical experience intensity — a substrate-level mechanism affecting the entire cortex. If aphantasia involves constitutively reduced top-down visual connectivity, the overlay effect should be absent while the substrate effect persists. Existing case reports confirm the pattern depends on subtype. David Luke reported zero imagery across 1,000+ DMT sessions in a congenital aphantasic — nothing in the overlay to amplify. Dos Santos and Rebecchi each reported imagery emergence in cases where the overlay hardware may have existed but was disconnected — the psychedelic apparently forced through weakened connections. The fact that visual response goes different directions is not a problem. It is the most informative possible outcome. The critical prediction is that therapeutic benefit (mystical experience, belief revision, symptom reduction) should converge across all subtypes regardless of visual response — because the therapy operates at the substrate level, not the overlay.

No controlled study has ever tested this. The standard outcome measures haven't been stratified by imagery ability despite this being a straightforward analysis. Including aphantasic participants in psychedelic trials would provide, at minimal cost, the first clean dissociation between overlay-level visual phenomena and substrate-level therapeutic mechanisms.

For trauma therapy — and this is about everyone¶

Standard trauma therapy relies heavily on guided imagery — "picture a safe place," "visualize your younger self," "imagine a container for your distress." For aphantasic clients, these instructions are dead links. Mawtus et al. (2024) confirmed this empirically: aphantasic individuals with PTSD described flashbacks as predominantly emotional and bodily rather than visual, only 3% reported their clinician understood aphantasia, and imagery-based therapies were reported ineffective — with the absence of visual intrusions leading to misdiagnosis toward depression rather than PTSD. For trauma survivors with vivid imagery, the situation is worse: the overlay isn't just useless — it's actively hostile.

PTSD is characterized by the hijacking of the imagery overlay. A 2025 Baycrest study (Yeung et al., n = 3,203 across two samples) demonstrated that vivid object imagery is literally a risk factor for PTSD severity. The safe-place visualization asks the patient to use the same cortical rendering engine that produces their flashbacks to produce their safety. The overlay has been weaponized.

Guided interoception — routing therapeutic intervention through the body-based substrate — offers more navigable therapeutic territory. But an honest account must acknowledge: the substrate is not immune to trauma either. For survivors of physical abuse, sexual assault, or torture, the body itself carries trauma signatures — somatic flashbacks, pain re-experiencing, visceral re-experiencing through exactly the interoceptive pathways proposed here as therapeutic routes.

The critical difference is topology. Overlay contamination tends to be systemic — the whole rendering engine that produces flashbacks is the same hardware asked to produce the safe place. Substrate contamination is typically regional — specific body areas are triggering while much of the interoceptive landscape remains navigable. Somatic Experiencing already works this way: beginning with neutral somatic territory (feet on floor, breath at nostrils) and working outward carefully. Guided interoception offers a larger navigable safe zone, not total immunity — and clinicians need training in navigating somatic territory with the same sophistication they bring to imagery-based work.

The 2,500-year precedent — developed for people with full imagery¶

Vipassana meditation — the technique through which the historical Buddha reportedly achieved enlightenment — is fundamentally an interoceptive practice. The body scan directs attention systematically through bodily sensations with no visualization. The Goenka tradition, training millions over 2,500 years, works exclusively through observation of actual physical sensation. Kabat-Zinn adapted this into MBSR, producing one of the most empirically validated psychological interventions in existence.

Zen's zazen directs attention to posture and breath without imagery. Centering Prayer releases all mental images. Quaker "expectant waiting" attunes to bodily promptings without visual content. Sufi dhikr combines rhythmic breathing with physical movement. The hesychast tradition anchors prayer in the heartbeat.

These traditions were not developed for people who couldn't visualize — their practitioners have full imagery capacity. They were developed because attending to the substrate directly, bypassing the overlay, produces deeper and more reliable access to altered states and contemplative insight — for everyone. This is the strongest possible evidence that the substrate, not the overlay, is where the deepest work happens.

What mystical experience actually is¶

The framework provides a complete first-principles account of what happens during mystical and spiritual experiences — one that validates the phenomenology while grounding it in identifiable neuroanatomy.

Craig's model establishes that the anterior insular cortex generates an integrated meta-representation of body state. Normally, the systems that maintain self-other boundaries (DMN for narrative self, superior parietal cortex for spatial self-boundaries) keep this integration parcellated. Direct neurological evidence comes from Picard (2023): patients with epileptic seizures originating in the anterior insular cortex report ecstatic/mystical experiences — unity, bliss, self-transcendence — with ictal SPECT confirming increased insular blood flow. When sustained meditation, psychedelics, breathwork, or spontaneous state shifts suppress these boundary-maintaining systems, the interoceptive substrate achieves maximum integration without parcellation. The experience of unity is the computational event of boundary-dissolution. Everything becomes one because the processing that maintains separateness has temporarily ceased.

Panksepp's subcortical emotional systems — SEEKING (engaged openness) and CARE (unconditional warmth) — are normally constrained by cortical executive control. When executive systems are suppressed, these ancient systems operate with reduced restriction. The experience of profound connection, love, and peace is their direct phenomenology, liberated from top-down modulation.

The MEQ30 factors map directly: Mystical (unity = boundary dissolution), Positive Mood (subcortical CARE/SEEKING liberated), Transcendence of Time/Space (narrative sequencing offline), Ineffability (the experience was generated by substrate-level systems beneath the linguistic cortex — the narrative system literally was not online during the event it's asked to describe afterward).

These are real neurological events, happening locally, through identifiable anatomy. The contemplative traditions were right about the method (body-based), right about the phenomenology (unity, peace), and right about the pathway (through the body). The attribution to an external higher power is the narrative cortex — coming back online afterward — constructing an explanation for an event that occurred while the narrative system was offline. The most available framework for "I experienced something profoundly real that dissolved my separateness" is, for most humans throughout history, the divine. This doesn't diminish the experience. It validates the methodology while grounding the phenomenology in the hardware.

The simulation-lucid phenotype contributes uniquely here: aphantasic individuals experiencing these states would report them without visual metaphors (light, radiance, visions) — as they actually are at the substrate level. An experiential window into what these states are made of beneath the overlay that normally dresses them up.

For education¶

When an aphantasic child arrives at a correct answer through somatic-intuitive processing — the substrate — but cannot demonstrate the standard visual-spatial reasoning steps that rely on the overlay, "show your work" becomes systematic invalidation of their actual cognitive process. The child's primary way of knowing is treated as insufficient or nonexistent. For spatial and mathematical problems, the child may be literally constructing models through what we term proprioceptive spatial construction (PSC) — holding geometric relationships in hand position, navigating mathematical structure through body-based coordinate systems. "Show your work" demands externalization of a visual-spatial process, but the child's process is proprioceptive-spatial. They cannot show it because it happened in a modality that leaves no visual trace.

This creates compounding damage: the cognitive channel is invalidated by educational authority; the invalidation is structurally invisible (embedded in standard pedagogy); and the suppression reinforces itself as the child learns to distrust their somatic knowing. When combined with trauma-driven hypervigilance in later life, two independent suppression mechanisms converge: a person with a computationally powerful substrate-level evaluation system that they've been systematically trained not to trust.

Importantly, this isn't only an aphantasia problem. The ERIC somatic/embodied learning review (2002) identified that Western education has systematically separated cognitive knowledge from embodied knowledge and suppressed bodily knowing. Aphantasia makes this suppression maximally visible, but it affects every student whose substrate-level processing is overridden by assessment tools designed to evaluate the overlay.

For understanding consciousness itself¶

Cross-species evidence demonstrates that complex social cognition — empathy in rats, grief behaviors in elephants, sophisticated social structures in cetaceans — operates in brains that share the interoceptive-somatic substrate but differ dramatically in cortical overlay. Panksepp's research showed that coherent emotional behaviors are elicited exclusively from subcortical regions, with no dramatic emotional responses ever produced by neocortical stimulation. Hydranencephalic children — born without most cerebral cortex — show emotional expression, social recognition, and situationally appropriate behavior.

This suggests: the overlay may be an evolutionary addition to an already conscious substrate, not the source of consciousness itself. The anterior insula's progressive integration of body states, the somatic marker system's pre-conscious decision guidance, subcortical emotional circuits' capacity for complex social behavior, and PSC's demonstration that the substrate can actively construct and manipulate spatial models — not merely evaluate — all point toward awareness and cognition rooted in the interoceptive-proprioceptive substrate. The overlay adds rendering, not cognition. The system that aphantasia makes visible by removing the overlay is not a backup. It is the foundation.

What We're Proposing¶

Immediate research priorities¶

Cross-compound aphantasia study. Complete aphantasics stratified by subtype (congenital/deep vs. acquired) and matched typical-imagers under psilocybin, ketamine, and placebo. Primary measures: MEQ30, 5D-ASC with subscale decomposition, therapeutic outcomes, interoceptive measures (MAIA-2), HRV/vagal tone. The subtype stratification is essential: if visual response varies by subtype while therapeutic outcomes converge, this cleanly dissociates overlay from substrate.
Retrospective 5D-ASC/MEQ30 stratification. Existing psychedelic trial datasets re-analyzed by VVIQ score. Lowest-cost, highest-yield immediate analysis.
Guided interoception protocol development. Formalization as a coherent clinical framework — drawing from Focusing, MABT, SE, body-scan meditation, and the Felt Sense Polyvagal Model — with standardized protocols, training materials, and outcome measures. Must incorporate somatic trigger navigation for physical/sexual trauma populations. Serves three populations: absent overlay (aphantasia), contaminated overlay (PTSD/CPTSD), and anyone seeking deeper substrate access (contemplative practitioners, all clients per Gendlin's outcome data).
Imagery vividness as PTSD risk factor screening. Integration of VVIQ into standard trauma assessment — identifying both aphantasic patients who need interoceptive pathways and high-vividness patients whose overlay may be actively exacerbating their condition.
Educational screening study. VVIQ administered to students identified as "gifted but underperforming" to test whether aphantasia is overrepresented in this group.

Differential predictions¶

These predictions are testable and falsifiable:

Psilocybin visual response should vary by subtype: congenital/deep aphantasics should show minimal VR (nothing to amplify), acquired aphantasics may show VR emergence (reconnecting existing hardware), intermediate cases may show first-ever visual experiences (latent capacity crossing threshold). The critical prediction: therapeutic outcomes should converge across subtypes regardless of visual response — dissociating the overlay from the substrate-level mechanism.
Ketamine dissociative effects should be fully present regardless of imagery status, since NMDA blockade operates at the substrate level.
Guided interoception should show equal or superior outcomes to guided imagery for high-vividness PTSD patients whose overlay is weaponized; comparable outcomes for low-vividness patients.
Mystical experience (MEQ30) should be achievable by aphantasic participants across all induction methods despite absent visual phenomena — confirming that mystical experience arises from substrate-level integration and boundary dissolution, not from the overlay.

Why Open-Source¶

This framework emerges from the conviction that technology and knowledge should serve rather than extract. The experiential insight underlying it — that body-based cognition is not a backup system but the universal substrate — comes from someone living inside this phenotype. The scientific grounding comes from decades of peer-reviewed work by researchers whose contributions this document attempts to synthesize rather than supplant.

We publish this openly because:

The interoceptive-somatic substrate operates in every brain — aphantasia simply makes it visible. Understanding what the removal of the imagery overlay reveals has implications for everyone: for aphantasic individuals who deserve to understand their neurology as architectural variant rather than deficit; for trauma survivors whose overlay has been weaponized and who deserve to know that the substrate offers navigable therapeutic territory; for contemplative practitioners whose traditions have always pointed to the substrate beneath the overlay; for clinicians who need a formalized body-based framework with the same institutional standing as guided imagery; for educators who unknowingly invalidate students processing through substrate-level channels; and for researchers who need testable hypotheses about what consciousness — and what mystical experience — actually requires.

Methodology Note: AI-Augmented Autoethnographic Synthesis¶

This document was produced through AI-augmented autoethnographic synthesis — a collaborative process in which a human researcher's lived experience with complete aphantasia, anauralia, and mirror-touch synesthesia served as primary phenomenological data; an AI system (Claude, Anthropic) performed literature retrieval, reference verification, and prose synthesis; and the theoretical framework emerged through iterative conversational refinement where experiential observations generated hypotheses tested against the literature and corrected through critical feedback.

The human researcher (Steven Kirkland) provided experiential data, cross-domain pattern recognition, and critical evaluation — including identifying theoretical errors in the AI's output. The AI provided literature access at scale but also introduced limitations: initial retrieval was via web search, with subsequent structured PubMed searches across key topic intersections; however, these searches remain not PRISMA-compliant (no formal Boolean/MeSH queries, no PsycINFO/Cochrane/Web of Science access, no pre-registered protocols or quality assessment). AI synthesis carries the risk of subtle source mischaracterization. Autoethnographic observations are n=1 and require empirical validation. Earlier versions contained stance errors and overstated claims that were corrected through the iterative process. Every prediction in this framework is designed to be falsifiable through standard experimental methods.

Full methodological discussion in the main research document.

Key References¶

This companion piece synthesizes research from the following primary sources (full citations in the main research document):

Aphantasia neuroscience: Zeman et al. (2015, 2024); Pearson, Keogh, Koenig-Robert (2019–2025); Liu (2023, 7T fMRI); Chang et al. (2025); Bouyer & Arnold (2024, deep aphantasia)

Ventral/dorsal dissociation & PSC: Farah et al. (1988); Bainbridge et al. (2021, drawing double dissociation); Reeder et al. (2024, strategy use); Phillips (2025, spared spatial imagery); Ernst & Banks (2002, visual suppression of proprioception); Wasaka & Kakigi (2012, SI suppression); Graziano (1999, hand-anchored neurons)

Interoceptive hierarchy: Craig (2002, 2003, 2009); Damasio (1991, 1994, 1996); Silvanto & Nagai (2025a, 2025b predictive coding account); Nagai et al. (2025, n=468); Monzel et al. (2025, imagery-interoception-mental health mediation); Monzel, Karneboge & Reuter (2024, aphantasia/alexithymia overlap)

Psychedelic mechanisms: Carhart-Harris & Friston (2019, REBUS); Griffiths (2006–2018, Johns Hopkins mystical experience); Stoliker et al. (2024, Mol Psychiatry, top-down visual imagery mechanism); Siegel et al. (2024, Nature, global desynchronization); Brudner et al. (2025, mystical experience predicts PAP outcomes); 2025 REBAS study (belief revision)

Psychedelics & aphantasia subtypes: Luke (2018, 1,000+ DMT, no imagery); Dos Santos (2018, acquired aphantasia, imagery restored); Rebecchi (2023, VVIQ 16→80 after psilocybin)

Imagery as PTSD risk factor: Kosslyn (2005); Morina et al. (2013); Bryant & Harvey (1996); Yeung et al. (2025, Clin Psychol Sci, n = 3,203); Clark & Mackay (2015)

Somatic flashbacks/contamination: Whalley et al. (2021); Levine/Payne et al. (2015, Somatic Experiencing titration)

Subcortical emotion: Panksepp (1998, 2010); Merker (hydranencephaly)

Body-based therapy: Gendlin (1978, 1981, Focusing/felt sense); Price (MABT); Levine/Payne (2015, SE); Winhall (2021, FSPM); Ogden (Sensorimotor Psychotherapy)

Contemplative traditions: Satipatthana Sutta (body scan); U Ba Khin/Goenka (Vipassana); Kabat-Zinn (MBSR); Kok & Singer (2017); Fischer et al. (2017)

Mystical experience mechanism: Craig (AIC integration); Picard (2023, ecstatic epilepsy/anterior insular cortex); Newberg (parietal suppression); Cristofori et al. (2016, TBI/mysticism); Panksepp (subcortical SEEKING/CARE); Griffiths (lasting personality change)

Polyvagal/trauma: Porges (1995–2025); Van der Kolk (2014); Murphy et al. (2022); Levin et al. (2024)

Childhood invalidation: Krause, Mendelson & Lynch (2003); Linehan (1993); Greenes (1981); ERIC (2002)

Aphantasia clinical adaptation: Mawtus, Renwick, Thomas & Reeder (2024, Collabra: Psychology, aphantasic PTSD flashbacks predominantly emotional/bodily); Reeder & Mawtus (2023, 2025, Aphantasia Network)

This document is part of an open-source research framework. For the full literature review and research proposal, see: "The Simulation-Lucid Phenotype: Aphantasia as a Window into Ancient Cognition and Psychedelic Mechanisms."