For partners + investors

Drug-free cortisol management for speech-motor fluency.

FluentPlay is a real-time voice-driven digital therapeutic platform for stuttering. Every disfluency event triggers cortisol. Repeated events condition the brain to release cortisol before the word is even attempted. FluentPlay breaks that loop — lowering cortisol during sessions, weakening the conditioned response over time, and preparing users for real-world speech with less fear. No one else is here. The circuit is unmapped. The market is unowned.

The opportunity

White space in neuroscience

Stuttering affects approximately 3 million adults in the United States. There is currently zero pharma presence, zero FDA-cleared digital therapeutics, and no existing intervention that targets pre-articulatory planning — the stage where stuttering originates.

~3M
US adults affected
0
FDA-cleared DTx
0
Pharma presence
Circuit adjacency

Same loop. Different entry point.

The basal ganglia-thalamocortical loop that controls motor gating for speech is the shared substrate. Both conditions involve involuntary disruption of speech output through circuit-level timing failure — but at different nodes.

Nuedexta (PBA)
Pseudobulbar affect
Involuntary emotional expression and speech disruption. Corticobulbar pathway fails to regulate brainstem motor output. Pharmacological intervention at the glutamate/sigma-1 receptor level.
FluentPlay (PAD)
Stuttering
Involuntary speech timing failure. Pre-SMA fires unstable motor plans; putamen gates with learned disruption. Digital intervention at the motor-planning level through real-time acoustic feedback.
Shared neural circuit
Cortex Basal ganglia Thalamus Motor output

Both conditions disrupt the motor gating loop — PBA at brainstem regulation, stuttering at pre-articulatory planning

The cortisol loop

Why stuttering reinforces itself

Every stuttering event is a neurochemical event. Understanding that loop is what makes drug-free intervention possible.

The reinforcement cycle
01
Disfluency event
A block or repetition occurs on a specific motor sequence — the /k/ in "cat," the /s/ in "say."
02
HPA axis activation
The hypothalamic-pituitary-adrenal axis fires. Cortisol releases in real time — not hours later, but within the moment of the block.
03
Conditioned anticipation
Repeated events on the same sound train the amygdala to trigger cortisol before the word is even attempted. The body learns to expect failure at that motor sequence.
04
Degraded motor gating
Elevated cortisol impairs basal ganglia timing precision. The putamen's gating becomes more erratic — making the next attempt on that sequence more likely to fail.
↻ cycle repeats
Breaking the loop without drugs

Game-based therapy creates a low-stakes repetition environment where the motor sequence can fire repeatedly without triggering the full threat response. Each successful production reduces the conditioned cortisol spike. Over sessions, the anticipatory response attenuates — the amygdala stops flagging that sequence as dangerous. The wiring rewrites.

This is not relaxation therapy. It is structured neurochemical habituation through controlled motor repetition — measurable through PAD scoring, achievable without pharmacological intervention.

FluentPlay is conducting ongoing research into the relationship between PAD-scored acoustic features and cortisol-mediated motor disruption, with the goal of validating game-based intervention as a measurable, drug-free therapeutic pathway for speech-motor fluency.

Therapeutic mechanism

The multiplier as a drug target

PAD models disfluency as the product of Pressure and Anxiety — not the sum. This multiplicative relationship means a targeted intervention on one factor produces outsized reduction in the disfluency signal. It behaves like a dose-response curve.

Live: P × A = D

Drag the sliders. Watch what happens to the disfluency signal when you cut just one input.

P
75
A
65
Disfluency score
4,875
75 × 65
If you halve Anxiety
2,438
75 × 33

Clinical implication: FluentPlay's six game modes each target Pressure, Anxiety, or both. Summit (exposure therapy) reduces Pressure through repetition. Rainbow Syllables reduces Anxiety through real-time feedback. The multiplicative structure means partial reduction in either factor yields disproportionate clinical gain — without pharmacological intervention.

Outcome data

Measurable change within a single session

The PAD framework produces per-syllable, per-round analytics. Below is data from a session — four rounds of "The cat sat on the mat" — showing system stabilization in real time.

Session data"The cat sat on the mat" — 4 rounds
Ground58% → 89%
Ground strengthened — 58% to 89% over 4 rounds
Pressure
10%
↓8
Anxiety
9%
↓19
Disfluency
7%
↓13
Final round — per syllable
The
P
6
A
10
D
5
cat
P
17
A
16
D
13
sat
P
12
A
10
D
8
on
P
4
A
5
D
3
the
P
5
A
4
D
3
mat
P
13
A
9
D
9
Clinical insight
Pressure decreased 8% across 4 rounds. Anxiety dropped 19%. Disfluency fell 13%. Ground moved from 58% to 89%. The system settled into a stable rhythm — strong foundation for increasing difficulty.
Biomarker pathway

From consumer app to neural biomarker

FluentPlay is developing a wearable fNIRS protocol in collaboration with NIRx to characterize pre-SMA hemodynamic activation during speech planning. This is the bridge from acoustic inference to direct neural measurement — transforming FluentPlay from a consumer tool into a biomarker-backed digital therapeutic.

01
PAD scoring
Per-syllable acoustic features (VOT, formants, F0)
02
fNIRS capture
NIRSport2 — pre-SMA hemodynamic activation
03
Correlation
Map PAD scores to cortical activation patterns
04
Biomarker
Validated neural endpoint for stuttering intervention

Core hypothesis: Stuttering reflects predictable instability during pre-articulatory planning — measurable via hemodynamic response in the pre-SMA before articulation onset. If validated, PAD scores become a non-invasive proxy for a neural biomarker, enabling clinical trial endpoints without imaging.

Asset summary

What FluentPlay is

FluentPlay is acquirable at pre-Phase I cost with a differentiated IP position, a working consumer product, and a biomarker development pathway.

Novel IP
PAD framework — Pressure × Anxiety → Disfluency ↕ Ground. Proprietary model of stuttering as pre-articulatory timing instability. No prior art at this level of specificity.
Working product
Six voice-driven game modes deployed as WebGL. Real-time mic input, Web Speech API, per-syllable PAD scoring. Personalizable to each user's speech patterns and target sounds.
Biomarker pathway
NIRx fNIRS collaboration. NIRSport2 protocol targeting pre-SMA activation. Bridge from acoustic proxy to direct neural measurement.
Drug-free cortisol management
Structured neurochemical habituation through game-based motor repetition. Lowers cortisol during sessions, weakens conditioned anticipatory responses over time, and prepares users for real-world speech with less fear — without pharmacological intervention.

Interested in exploring a strategic conversation?

willcarbone@fluentplaytech.com