SOPHROS
RAT Research Portal
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SOPHROS
Internal access only. Enter the team password to continue.
A single reference portal for the Sophros data & research team — every training library, every instrumentation, the clinical evidence, the brain systems engaged, and the data-quality trail behind it all.
Each library is a purpose-built soundscape targeting a domain of regulation. Click any card to open its instrumentation.
Use the search box in the top bar to jump to any instrument, sub-domain, brain region, or citation from anywhere in the portal.
Every documented instrumentation across the eight libraries, in Coral's six-field template. Filter, search, and expand any row for the full record and its data-quality status.
How many instruments in each library target each sub-domain. A sub-domain's home library is outlined; filled cells outside it reveal cross-library targeting and overlap. Click a cell to open those instruments.
The library-to-brain map. Below the view, each region links to the libraries and instruments that engage it.
18 regions engaged across the protocol. Click a library pill to open its instrumentation.
RAT is open-loop auditory entrainment. Because it works through the auditory system — the brain's fastest and most precise timing channel — its effects are electrophysiologically visible at every level, from brainstem phase-locking to cortical steady-state and event-related potentials. This section maps how each soundscape corresponds to an EEG signature, how a qEEG / ERP workup can target a protocol, and how the same measures validate it pre- and post-training.
It is meant to sit alongside closed-loop neurofeedback, not to compete with it. Neurofeedback trains the brain to change its own output through reinforcement; RAT supplies a precisely-timed external drive the brain phase-locks to. qEEG is the instrument that can select the drive and confirm it landed — closing the loop RAT itself leaves open.
Carrier pitch is not brainwave frequency. A 135 Hz tone does not create a 135 Hz cortical rhythm. Neural entrainment rides the amplitude envelope — the modulation rate, beat tempo, and onset periodicity of the sound — not the carrier.
A carrier can sit anywhere in the audible band while its envelope is modulated at, say, ~10 Hz to engage alpha, or delivered at 40 Hz to drive the gamma ASSR. Every correspondence below targets envelope / beat rate and treats carrier frequency as a separate axis (timbre, tissue engagement, comfort).
Five levels of measurement, ascending the same pathway the protocol is built on:
The frequency-following response is scalp-recorded phase-locking to the sound's periodicity and envelope. Auditory training improves neural timing in the brainstem (Kraus and colleagues) — the direct electrophysiological substrate of RAT's founding premise.
A sound amplitude-modulated at a fixed rate drives a scalp response at that rate. The 40 Hz ASSR indexes gamma-band excitation/inhibition balance and is reduced in schizophrenia (robustly), autism, and bipolar disorder.
How the auditory system filters redundancy (P50 paired-click suppression) and flags deviance (mismatch negativity) before attention engages. Impaired gating shows up in PTSD and schizophrenia; MMN indexes discrimination.
The P300 tracks how resources are allocated to salient events. Rhythmic auditory stimulation has been shown to improve P300 measures in Parkinson's disease.
Band power (delta→gamma), ratios, peak alpha frequency, frontal asymmetry, and coherence — the trait-level map a brain-mapping workup produces, and the baseline RAT is measured against.
The same brain model as the Brain tab, re-mapped to electrophysiology. Toggle between biomarkers and frequency bands, click a signature to light its cortical generators, click any region for its EEG signature, and switch on the 10-20 electrode montage to see where each marker is recorded.
Every row is calibrated. Established = well-replicated in the literature. Emerging = the marker is established but RAT's effect on it is early-stage. Rationale = a mechanistic prediction extending a known effect, not an outcome claim.
| EEG marker | What it indexes | Common dysregulation | RAT correspondence · envelope / beat target | Evidence |
|---|---|---|---|---|
| FFR / cABR brainstem phase-locking | Temporal precision of sound encoding | Jittered / degraded timing in language, reading and auditory-processing difficulty | L1 L4 Steady low-frequency envelope; sub-bass carrier — strengthen the following response | Established |
| 40 Hz ASSR gamma band | Cortical E/I balance, sensory binding | Reduced amplitude / delayed phase in ASD, schizophrenia, bipolar | L2 Envelope modulation toward the gamma range; sensory-integration soundscape | Marker Established · RAT effect Emerging |
| P50 gating paired-click suppression | Filtering of redundant input | Impaired suppression in PTSD, schizophrenia (mixed in ASD) | L2 L5 Predictable, low-novelty field lowers the gating load | Marker Established · RAT effect Rationale |
| MMN mismatch negativity | Preattentive auditory discrimination | Reduced in schizophrenia; atypical in ASD and dyslexia | L2 L6 Structured deviance within voice-range / social soundscapes | Marker Established |
| P300 P3b | Attentional & working-memory allocation | Reduced amplitude / delayed latency in ADHD and Parkinson's | L3 Beat-based attentional scaffolding; cognitive-timing soundscape | Established · RAS→P300 supported in PD |
| Theta/beta ratio TBR | Cortical arousal / inattention | Historically elevated in an ADHD subgroup | L3 Arousal-lifting, beat-anchored attention soundscape | FDA-cleared adjunct, but not a reliable standalone diagnostic (Arns et al., 2013) |
| Peak alpha frequency PAF / IAF | Processing speed, arousal set-point | Slower PAF in cognitive slowing and schizophrenia | L3 L7 Support arousal / alertness | Putative marker · standalone value debated |
| Frontal alpha asymmetry FAA | Approach / withdrawal, mood valence | Leftward hypoactivation linked to depression vulnerability (Davidson) | L5 L7 Mood- and arousal-oriented soundscapes | Small effect · limited standalone diagnostic value (meta-analysis, 2025) |
| High-beta excess ~20–30 Hz | Hyperarousal, vigilance | Elevated in anxiety and PTSD hypervigilance | L5 L7 Parasympathetic-leaning low-frequency foundation | Rationale / Emerging |
| Frontal slow-wave delta / theta | Under-arousal, dysregulation | Frontal slowing in TBI and regulatory disorders | L1 Autonomic down-regulation via the settle phase | Rationale |
Library key — L1 Nervous System Regulation · L2 Sensory Processing · L3 Attention · L4 Motor Control · L5 Behavioral Regulation · L6 Social Engagement · L7 Arousal & Stress · L8 Body Awareness
A qEEG-guided RAT protocol runs the same arc a clinician already knows — assess, target, deliver, re-assess — with the soundscape as the intervention:
Resting qEEG plus a targeted ERP / ASSR panel produces the individual's electrophysiological profile.
Flag the dysregulated signatures — e.g. blunted 40 Hz ASSR, impaired P50 gating, elevated high-beta, slow peak alpha.
Each marker points to the soundscape whose mechanism addresses it, using the table above.
Choose modulation / beat rate and tempo to the targeted band. Carrier, timbre and spatialization are set separately for comfort and tissue engagement.
Repeat the panel to quantify change — the objective outcome. qEEG closes the loop that open-loop stimulation leaves open.
| Band | Range | State / function | Envelope · beat correspondence | Libraries |
|---|---|---|---|---|
| Delta | 0.5–4 Hz | Deep rest, down-regulation | Very slow envelopes; settle phase | L1 |
| Theta | 4–8 Hz | Drowsy, memory, trauma processing | Slow beat; meditative tempo | L1, L7 |
| Alpha | 8–12 Hz | Relaxed wakefulness | ~8–12 Hz envelope; relaxed tempo | L3, L7 |
| SMR | 12–15 Hz | Calm focus, motor stillness | Steady mid-tempo beat | L3, L4 |
| Beta | 15–30 Hz | Active cognition (excess → anxiety) | Brisker beat; down-regulate for hyperarousal | L3 · down-regulate L5, L7 |
| Gamma | ~40 Hz | Binding, sensory integration | 40 Hz amplitude modulation (ASSR) | L2 |
Read this as correspondence, not conversion. These are envelope / beat targets and mechanistic rationales — not a claim that passive listening reliably shifts a fixed resting-band power in every individual.
Several of these markers have been over-sold historically and later qualified — theta/beta ratio, frontal alpha asymmetry, and peak alpha frequency all have documented limits as standalone diagnostics. We treat them as elements of a profile, not single-number verdicts, and we distinguish an established marker from an established RAT effect on that marker. That separation is deliberate: it is what makes the correspondences above defensible in front of someone who reads this literature for a living.
| qEEG | Quantitative EEG — normed, statistical brain mapping of band power, ratios, asymmetry and connectivity. |
| ASSR | Auditory steady-state response — scalp response entrained to a fixed sound-modulation rate; 40 Hz variant indexes gamma / E-I balance. |
| FFR / cABR | Frequency-following / complex auditory brainstem response — subcortical phase-locking to a sound's periodicity; a timing-precision readout. |
| P50 gating | Paired-click suppression — how well the brain dampens its response to a repeated, redundant stimulus. |
| MMN | Mismatch negativity — preattentive response (~100–250 ms) to an auditory deviation from a regular pattern. |
| P300 | Positive deflection (~300 ms) reflecting attentional and working-memory allocation to a salient event. |
| PAF / IAF | Peak / individual alpha frequency — the dominant alpha rhythm; a putative index of processing speed and arousal. |
| FAA | Frontal alpha asymmetry — left/right frontal alpha balance, linked to approach/withdrawal and mood. |
| Open- vs closed-loop | RAT is open-loop (external timed drive the brain phase-locks to); neurofeedback is closed-loop (the brain's own output reinforced back to it). qEEG can target and validate both. |
Kraus & Chandrasekaran (2010), Nat. Rev. Neurosci. — auditory training & brainstem timing · Picton et al. (2003), Int. J. Audiol. — human ASSR · Thuné, Recasens & Uhlhaas (2016), JAMA Psychiatry, and subsequent meta-analyses — 40 Hz ASSR in schizophrenia/ASD · Näätänen et al. — MMN · Polich (2007), Clin. Neurophysiol. — "Updating P300" · Monastra et al. (1999) & Arns, Conners & Kraemer (2013), J. Atten. Disord. — theta/beta ratio · Klimesch (1999), Brain Res. Rev. — alpha/theta & cognition · Davidson — frontal EEG asymmetry · Grahn & Brett (2007), J. Cogn. Neurosci. — beat perception in motor areas · rhythmic-auditory-stimulation gait meta-analysis (2017), Sci. Rep. Full, tagged list on the References tab.
RAT is built on a single premise: the auditory system is the brain's fastest and most precise timing instrument. Vision is comparatively sluggish and tactile input is moderate; only the auditory pathway delivers temporal information at the resolution the nervous system needs for regulation, attention scaffolding, and motor entrainment. Every library in the protocol is an application of that fact.
Open any library's full instrumentation and protocol envelope:
A periodic beat elicits a sustained, frequency-locked cortical response — the nervous system doesn't merely hear a pulse, it resonates at it. Cardiovascular and respiratory variables track musical tempo directly.
A repeating, transient-free field drives auditory prediction error toward zero. The reduction of acoustic uncertainty is what the threat-detection system reads as safety — regulation before thought.
Low-frequency sound directly stimulates the otolith organs, tuned to sub-100 Hz vibration below auditory threshold. Sub-bass is felt by the body — the most reliable somatic tether for a dissociated client.
Warm, human-sourced timbre maps onto limbic circuitry, and low-frequency content entrains brainstem and autonomic activity toward parasympathetic dominance.
Sub-250 Hz content appears in every library. Lower frequencies prime and regulate before any other element does training work — the shared floor the protocol is built on.
Library 1 is acute and state-based — discrete episodes needing in-the-moment de-escalation (fast rescue, 60–80 BPM). Library 7 is tonic and trait-based — the persistent resting set-point retrained slowly (50–65 BPM, measured by cortisol/GAD-7/PSQI). A symptom belongs to whichever library's soundscape actually treats it.
Every citation is real and verifiable. Where a predicted effect extends an established mechanism into a new application, that is framed as a mechanistic rationale, not an outcome claim. See References for the full list, tagged by evidence type.
Select the sub-domains present in the client's intake. The tool maps them to the libraries whose soundscapes treat them and assembles a recommended layering recipe from the documented instrumentation.
This page codifies the rules the reference set follows, so the data is auditable and any team member can extend it consistently.
| Field | Definition |
|---|---|
| Instrumentation | The categorical musical element / folder that houses the individual audio files. |
| Label / s | The audio files inside the folder, with the filename schema. |
| Definition | What the musical element is, in plain music-theory terms. |
| Target Symptom / Predicted Effect | Sub-domains targeted + predicted effect + the mechanistic reason (WHY) the element has that effect. |
| Auditory Variables | Frequency, BPM, spatial placement, key, beat structure. |
| Variances | (a) how it varies within the library; (b) how/why it varies with symptom severity. |
Libraries 1–6 use [Library].[Code].[Variation].[BPM].wav, where the second number is the instrument index (e.g. 3.2.XYLO.100.wav). Libraries 7–8 as recorded use a dotted key/BPM scheme (7.KICK.60.wav, 8.1.SPACEHARP.EM.70.wav). Known inconsistency: in L8, 8.1/8.2/8.3 is used as a variation index that restarts per folder — tracked as QC-01 on the Status page.
Each library owns a fixed set of neutral, non-diagnostic sub-domains (shown on the Coverage matrix and each library's envelope). Diagnostic labels (ADHD, PTSD, etc.) are deliberately avoided in the taxonomy in favor of symptom-level descriptors. An instrument may target a sub-domain owned by another library — those cross-links are what the coverage matrix surfaces.
A symptom is filed to whichever library's soundscape actually treats it. Acute / phasic / state-based presentations (discrete episodes, in-the-moment de-escalation, post-event recovery) → Library 1. Tonic / trait-based presentations (persistent resting set-point, chronic-stress physiology, retrained over days) → Library 7. This maps onto the clinical phasic-vs-tonic arousal distinction.
Sub-250 Hz content is intentional across all libraries, including those whose stated range sits higher — it is not an inconsistency. Lower always helps priming and regulation, so library Hz "floors" are not enforced.
Every citation is real and DOI-verifiable; no fabricated sources. Claims are written confidently but a predicted effect that extends a mechanism is framed as rationale, not an outcome. References are tagged Mechanism / Clinical / Framework on the References page.
The underlying deliverables — the source of truth the portal is generated from. Each is also rendered live below, no download needed.
All peer-reviewed sources, tagged by evidence type and linked to their DOI where available. Each lists the instruments that cite it. Export the full set for a reference manager.
Choose the population, then upload a completed RAT Soundscape Survey (.xlsx). The portal scores the 80 items, ranks the eight libraries, charts the profile, and produces an engineer-facing prescription with the survey-based reasoning behind every parameter. Each submission is saved to the History log.
Who else is working in our space worldwide — academic centres, companies, funders, professional bodies — what they have that we don't, and where the open ground is. Every entry links to a verifiable source.
Short courses, quizzes and games that teach how Rhythmic Auditory Training works — from the premise, through the eight libraries and the brain pathways, to reading a prescription and building a session. Progress is saved in this browser.