Mental Imagery and Cerebellar Motor Schema Simulation

PRO CUE: The brain does not own a DVD player — it owns a flight simulator. Mental imagery is not watching the stroke; it is running it, on the cerebellum's own predictive hardware, with the spinal output gated off. The simulation burns no glycogen, loads no tendon, and misses no flight connection. The only questions that decide whether it pays: which program you load, what speed you run it at, and which seat you sit in while it runs.

Video: Mental Imagery for Tennis (Brian Cain).

1. Executive Summary & Athletic Intent

Mental imagery — in its sport-relevant form, motor imagery — is the deliberate, structured rehearsal of a movement without executing it. The athlete closes the eyes and runs the serve: the ball bounces, the knees load, the legs drive, the strings click, the ball lands in the corner. Coaching history filed it under motivation; neurophysiology refiles it under covert execution. The evidence is unambiguous: imagining and performing a movement recruit substantially the same neural machinery — premotor cortex, supplementary motor area (SMA), parietal cortex, basal ganglia, and, decisively for this article, the cerebellum. During imagery the corticospinal tract becomes more excitable, task-specific muscles emit faint subliminal activity, heart rate climbs with imagined effort, and a spinal reflex gate closes (measured as H-reflex suppression) so the command never reaches the muscles. The difference between execution and imagery is the gate, not the program.

The central concept of this article is that imagery is simulation, not pictures — and the simulator is the cerebellum. The cerebellum maintains forward models: circuits that predict the sensory consequences of a motor command from a copy of that command, before — and independently of — the body acting on it. When the athlete imagines the serve, the motor command is generated in weakened form, its efference copy is fed to the cerebellar forward model, and the model's prediction is experienced as a quasi-perception — the felt swing, the seen ball, the heard contact. Each simulation run compares predicted outcome against intended outcome and updates the motor schema — the abstract rule-set (Schmidt's schema theory) that generalizes a stroke across infinite situational variants. The repetition is therefore real at the level where skill actually lives; only the musculoskeletal bill is waived.

Because the value of imagery is graded by functional equivalence — how completely the rehearsal recruits the execution circuitry — the applied science reduces to a stacking discipline. The PETTLEP framework (Physical, Environment, Task, Timing, Learning, Emotion, Perspective) is the checklist; Section 3 turns it into a five-step protocol.

The athletic intent is fourfold. First, free repetitions: injury windows, travel days, and deep-fatigue states become trainable hours — the simulator runs on attention, not glycogen. Second, consolidation amplification: a short imagery block after physical practice, and again before sleep, re-fires the day's fresh motor traces and strengthens what the session seeded (Articles 051, 060, 166). Third, pre-performance priming: the between-point serve ritual is a 5–8 second simulation that pre-selects the motor program before the ball is tossed (Articles 047, 075). Fourth, pressure-proofing: the simulator can expose a pattern to break points and hostile crowds without risking a single physical error.

Two warnings organize everything downstream. The simulator is amoral — it strengthens whatever it runs, including the error just committed, which is why vivid error replay is a training mistake, not a learning tool. And it is parasitic on physical practice — imagery amplifies schemas the body has actually built; it cannot conjure a skill that has never been seeded. Both failures are common, and both are correctable.

2. Biomechanical / Cognitive Foundation

2.1 Functional Equivalence: One Circuit, Two Modes

The modern literature on motor imagery rests on Jeannerod's formulation: imagining an action is entering a state of action simulation — a weakened but genuine activation of the executive machinery that would perform it. Brain imaging during motor imagery consistently shows activation in SMA, premotor and inferior parietal cortex, the basal ganglia, and the cerebellum — the same distributed network that executes, minus full-amplitude primary motor output. The overlap is the reason imagery trains anything at all.

Three lines of physiological evidence make the equivalence concrete. First, transcranial magnetic stimulation (TMS) over motor cortex during imagery reveals facilitated motor evoked potentials (MEPs) — the corticospinal pathway is primed — graded by imagined effort and specific to the muscles that would perform the action. Imagining a wrist snap excites wrist controllers, not ankle controllers. Second, surface EMG records small but reliable subliminal activity in the task muscles, coarsely time-locked to the imagined phases. Third, the autonomic system plays along: imagined effort raises heart rate and ventilation in rough proportion to the imagined load.

The engineering summary: execution equals command plus open gate; imagery equals command plus closed gate. Everything upstream of the gate — selection, sequencing, timing, prediction, evaluation — is shared. Because the circuitry is shared, imagery inherits the properties of the execution system: arousal, attention, fatigue, and environment degrade imagery exactly as they degrade execution. Imagery is a skill to be engineered, not a daydream to be prescribed.

2.2 The Cerebellar Forward Model: The Brain's Flight Simulator

The deepest reason imagery works is a latency problem. Sensory feedback from a movement arrives too late to steer it: the ball sits on the strings for 4–5 milliseconds, while visual recognition of impact costs over 100 ms (Article 041). The brain solves this with prediction. In the cerebellum — a structure holding over half the brain's neurons — the motor command is not only sent down the spinal cord; a copy of it (the efference copy) is routed to cerebellar circuitry that computes what the movement should feel and look like, before and independently of the body performing it. This is the forward model, and its core computation is a one-step state prediction:

$$\hat{s}_{t+1} = f(\hat{s}_t, u_t; \theta)$$

where $\hat{s}_t$ is the current estimated state of the body and ball, $u_t$ is the efference copy of the outgoing motor command, and $\theta$ is the parameter set of the model itself — the motor schema in machine form. During execution, the prediction is compared against the actual inflow of sensory re-afference; the mismatch is a teaching signal, delivered via the inferior olive's climbing fibers to Purkinje cells, that recalibrates $\theta$. During imagery, no re-afference arrives; the gate is closed. But the prediction still streams, and it is experienced — the felt load in the legs, the ball leaving the strings, the click. The comparison now runs against the intended outcome rather than the actual one, and the resulting error still updates $\theta$. The simulator trains even while the airframe is parked.

Two further properties matter for coaching. The forward model is deterministic given its inputs: garbage in (a corrupted reference, an imagined error) produces a confident, vivid, wrong simulation — vividness is fidelity to the model, not to the truth. And the simulation clock lives in the cerebellum: patients with cerebellar damage show disproportionate disruption of imagined-movement timing even when imagery content is intact. The cerebellum is not merely involved in imagery; it is the organ running the rehearsal at speed.

2.3 Motor Schemas: The Software the Simulator Runs

What exactly does the simulator rehearse? Not a recording. Schmidt's schema theory — the classical motor-learning account that modern internal-model language has largely absorbed — proposes that the nervous system stores no complete movement copies. It stores generalized motor programs: invariant structure (sequence, relative timing, phase organization) plus a rule-set — the schema — that maps initial conditions, parameters, and outcomes together. Two claims of the theory matter here. The recall schema selects parameters (how much knee, how much wrist) from intended outcome and current state; the recognition schema predicts what the movement should feel like, which is what lets an elite server know the ball is long before it lands.

Every physical repetition deposits one (movement, outcome) pair into the schema's training set. The schema generalizes from these samples — which is why a forehand hit from a thousand slightly different court positions remains one stroke. Imagery deposits predicted pairs: (imagined movement, predicted outcome). These are cheap, unlimited, and available anywhere — and only as good as the model that generates them (the honest limit of Section 2.7). The practical translation: imagery is the direct training of the recognition schema — the feel of a clean contact, the sound of a well-struck flat serve — and of the recall schema's parameter selection under imagined match conditions. When coaches say an athlete "doesn't yet have a feel for the shot," they are describing an under-trained recognition schema, and imagery is the most direct tool that exists for it.

2.4 The Muscular and Autonomic Fingerprint: The Body Believes the Simulation

The cleanest demonstration remains Yue and Cole's strength-transfer experiment: after several weeks of imagined-only training of a finger-abduction movement, participants gained roughly 20% in maximal force — not the ~30% of matched physical training, but far from zero, while a control group doing irrelevant mental work gained nothing. The gains were neural — improved central drive and motor-unit recruitment, not hypertrophy — and they established the principle: the body treats a well-run simulation as a training stimulus.

The fingerprint extends everywhere. MEP facilitation during imagery scales with imagined load — imagining lifting the heavy medicine ball excites the pathway more than imagining the light one. Heart rate and ventilation track imagined effort. And at the far end of the pathway, the H-reflex — the electrophysiological readout of spinal motoneuron excitability — is suppressed during imagery: the system actively closes its own output gate while the command is generated. The coaching translation is blunt: imagery does not build muscle and does not replace conditioning; it tunes the controller. It is a neural practice, and it should be dosed like one.

2.5 Mental Chronometry: The Simulation Runs at Real Speed

If the cerebellum runs the rehearsal, the rehearsal should obey the clock — and it does. Imagined durations approximate executed durations across a wide range of actions, and imagined aiming obeys Fitts's law — the same speed–accuracy trade-off governs real and imagined pointing. Temporal fidelity is the single most auditable property of an imagery rep: the gap between a timed imagined ritual and the timed real one is a direct quality score.

The fidelity is not free at the extremes. Very fast ballistic phases — the serve's acceleration window, well under 100 ms — are difficult to image in true time until the pattern is highly automatized; novices typically replay such phases "slower than life," while experts, whose schemas encode the phase structure, track it closely. And deliberately slow-motion imagery trains the timing schema at the wrong clock speed. Hence the rule: real-time is the default and the standard; slow motion is a form-audit tool, used briefly, and always finished with a return to real-time runs.

2.6 Perspective and Modality: The Seat You Simulate From

Imagery has a viewpoint and a sensory channel, and both change what it trains. The internal perspective (first-person, from behind one's own eyes) paired with the kinesthetic modality (the felt swing, ground pressure, grip tension) produces the strongest motor recruitment — the largest MEP facilitation and the most task-specific subliminal EMG — because it reproduces the vantage point the motor system operates from. The external perspective (watching oneself from outside, as on video) is weaker at recruiting the motor circuitry but superior for form auditing and tactical geometry — stance width, separation angle, the court coverage a pattern buys.

Skill level modulates the optimum: experts default to internal-kinesthetic imagery because they own the feel to simulate; learners need external visual modeling — reference video of their own best efforts — first, because a recognition schema must exist before it can be rehearsed from the inside. The full scene load for an elite rep stacks channels deliberately: kinesthetic (grip pressure, knee load, trunk release), visual (ball flight, court geometry), auditory (the contact sound — a direct readout of strike quality), and contextual (score, weather, emotional charge). The kinesthetic channel trains the schema; the others load the scene so the simulation recruits the whole circuit.

2.7 Dose–Response and the Honest Limits

The meta-analytic picture is consistent: imagery alone produces real but clearly smaller gains than physical practice; physical practice combined with imagery outperforms physical practice alone, with the advantage growing when physical volume is constrained — injury, fatigue, travel — and for tasks with heavy cognitive and timing components, the tennis serve chief among them. Imagery is thus best understood as a multiplier on physical practice, not a substitute for it.

Five limits keep the prescription honest. First, imagery cannot simulate what the body has never seeded. Rehearsing a professional's serve from the inside, before owning its components, is fantasy rehearsal: the forward model has no data, the prediction is generic, and the schema update is noise. Second, vividness is a trait with a distribution. Questionnaire measures (VVIQ and successors) show wide individual differences, with aphantasia at one extreme — imagery-blind but often kinesthesia-capable; such athletes train with procedural scripts and felt-sense cueing. Third, the simulator is amoral: it consolidates whatever it runs, so vivid error replay installs errors (Step 4 exists for this). Fourth, imagery slows but does not stop detraining — during immobilization it preserves cortical representations and partially protects strength and coordination: a maintenance drug, not a rehab program. Fifth, timing fidelity drifts with fatigue — a tired athlete's imagery runs long — so quality control belongs in every session (Section 4).

3. Step-by-Step Technical Execution

The simulator protocol runs in five steps. Steps 1 and 2 are built once per pattern and refreshed weekly; Steps 3–5 run every session.

Step 1 — Schema Selection and Reference Calibration

Choose one pattern plus one situation — not "the serve," but "the wide-slider kick on break point, ad side." Vague targets produce vague simulations. Then calibrate the simulator against the best available reference: 3–5 clips of the athlete's own best executions of that exact pattern (match footage preferred; a clean practice clip acceptable). Watch once at full speed for the gestalt, once in slow motion for the form audit, once with eyes closed immediately after — the afterimage method — to bootstrap the internal copy. Define in writing the feel target: the two or three felt signatures of the clean version (e.g., "weight into the front leg at contact; loose wrist at the top; contact sound sharp, not slappy"). The feel target is what every subsequent rep is scored against.

Step 2 — Build the Functional-Equivalence Stack (PETTLEP)

Engineer the rehearsal environment to match execution as closely as the situation allows, on all seven axes of the PETTLEP framework:

Physical — wear court kit, hold the racket, stand on court (or on any line, in any open space). The body is part of the simulation's input; give it the real props.
Environment — image at the venue, facing the real court geometry; when impossible, use a photograph or video still of the venue as the anchor.
Task — rehearse the exact task, including the situation: the score, the opponent's position, the previous point's residue. A serve imaged in a void is a different program from a serve imaged at 30–40.
Timing — real-time, always. Time the reference action once with a stopwatch and hold the imagery to it.
Learning — update the script as the physical pattern evolves; last month's cue words are this month's noise.
Emotion — include the arousal: the elevated heart rate, the crowd, the consequence. Imagery that is emotionally flat rehearses a nervous system that does not exist on match day.
Perspective — internal-kinesthetic for training reps; external perspective only as a deliberate, brief form audit.

Step 3 — The Simulation Run

Each rep is a complete situational sequence, not an isolated swing: read the opponent's kinematic cue (Article 044) → split step → load → strike → hold the outcome 2 seconds (ball landing, opponent's reply, recovery step). A rep runs 10–20 seconds. Execute 5–8 reps per set. Immediately after each rep, score two variables on a 1–5 scale: vividness (how completely the scene loaded) and controllability (did the simulation run the intended version, or drift). Scores below 3 are not counted as repetitions; they are counted as fatigue, and the set ends. Between sets, 30–60 seconds of quiet reset — the simulator runs on attention, and attention is the dosage-limiting resource.

Step 4 — The Error Protocol: Reframe, Never Replay

Images corrupt. The ball drifts long, the toss floats, the picture grays out mid-swing. The protocol is fixed and non-negotiable: stop the rep at the moment of corruption; reset with one slow exhale (Article 047); replay a clean highlight — 3 seconds of the athlete's best-ever version of the pattern, held vividly; then re-run the full rep. What is forbidden is the instinctive alternative: replaying the error in slow motion to "see what went wrong." The simulator strengthens what it runs; error replay installs the error. Analysis of an error belongs to video review, done in the external perspective, with the coach. The internal simulator's only job is to run the corrected version.

Step 5 — Interleaving and Consolidation

Attach imagery to physical practice at the moments the neuroscience predicts the largest return. Before a technical block: 3–5 minutes of imagery as neural priming — the same command-generation warm-up that Article 048 describes for the body's readiness, aimed at the brain's. Between physical clusters: one imagined rep for every two to three physical reps of the same pattern — the interleave meta-analysis favors, keeping the schema's sample stream dense without joint load. After the block: 5 minutes of imagery replaying the best 3–4 physical reps of the session, re-firing the fresh trace while it is labile. Before sleep: the same 5-minute replay, handing the day's pattern to overnight consolidation (Article 166). On days the body cannot train — travel, injury, tournament overload — the same protocol runs at up to double volume, with expectations adjusted to maintenance, not acquisition.

Context Modulation

Pre-match (evening before): 10 minutes — serve plans and return patterns for tomorrow's opponent, each ending in a held successful outcome. Emotion axis loaded to match-day intensity.
Between points (in-match): the 5–8 second micro-routine — one internal-kinesthetic rep of the upcoming serve plus the intended target, run inside the ball-bounce ritual. This is imagery's highest-leverage deployment: it pre-selects the motor program seconds before execution.
Changeovers: 30–45 seconds of target imagery for the next game's pattern, plus one physiological reset breath — program selection and arousal control in one routine.
Injury windows: daily 10–15 minute sessions on the immobilized pattern plus the healthy complement; the goal is representation maintenance, with strength and tissue qualities delegated to rehab.

4. Performance Metrics & Dosage

4.1 Performance Metrics

Metric	Measurement Method	Elite Benchmark	Recreational Benchmark
Vividness rating (per rep)	1–5 self-score immediately post-rep	≥ 4 sustained across sets	2–3, unrated or unrecorded
Controllability rating (per rep)	1–5 self-score: intended version ran	≥ 4; corrupt reps < 20%	Frequent drift, unmanaged
Duration fidelity	Stopwatch: imagined vs. actual ritual	Within ±10%	> ±30% or never timed
Imagery ability baseline	VMIQ-2 / SIAM questionnaire, both perspectives	High kinesthetic subscale	Unknown; visual-only
Session compliance	Imagery diary, sessions/week	3–5 logged sessions	"When I remember"
Interleave ratio in technical blocks	Practice log: imagery:physical	1:2–1:3, pattern-matched	None, or unstructured
Transfer test	Serve accuracy in target zone, imagery-programmed vs. baseline	+5–15% target hits after 4-week block	No measured effect
Consolidation replay compliance	Post-practice + pre-sleep replay logged	≥ 80% of technical days	Occasional

4.2 Training Dosage Parameters

The acquisition layer (learning a pattern): - 3–5 imagery sessions per week, 6–15 minutes each, one pattern per block. - 15–25 scored quality repetitions per session; stop the set when vividness falls below 3 — attention, not clock time, is the limiting resource. - Full PETTLEP stack on at least two sessions per week; a reduced stack (racket in hand, real-time, internal-kinesthetic) is acceptable on the road.

The interleave layer (attached to physical practice): - Pre-block priming: 3–5 minutes. - In-block interleave: 1 imagined rep per 2–3 physical reps, same pattern. - Post-block replay: 5 minutes on the session's best 3–4 executions.

The consolidation layer: - Pre-sleep replay: 5 minutes, same-day best reps, ending on the cleanest one. - On non-training days: one 10-minute session to maintain the pattern's availability.

The special-context layer: - Injury/immobilization: 10–15 minutes daily on the affected pattern (representation maintenance) plus imagery of the healthy side where clinically appropriate. - In-season: keep the between-point micro-routine and pre-sleep replay; cut acquisition blocks to maintenance volume — match play itself is already dense salient practice.

5. Errors, Causes & Corrections

Error	Cause	Consequence	Corrective Strategy
Outcome montage ("daydreaming winners")	No script, no task specificity; imagery prescribed as motivation.	Mood improves; schema unchanged — no movement–outcome pairs deposited.	PETTLEP script with the full situational sequence (read → load → strike → outcome hold); score every rep.
Chronic slow-motion replay	"Analyze more" instinct; imitation of video-review culture.	Timing schema trained at the wrong clock speed; real-time execution and rehearsal decouple.	Real-time as default; slow motion only as a brief external-perspective form audit, always finished with real-time runs.
Vivid error replay	Post-error rumination channeled into imagery.	The simulator consolidates the error — imagery actively installs the miss.	Step 4 error protocol: stop, exhale, replay clean highlight, re-run. Error analysis goes to external video, with the coach.
External-perspective-only imagery	Imagery modeled on watching TV; kinesthetic channel never trained.	Weak motor recruitment; tactical insight without schema update.	Internal-kinesthetic default for training reps; external reserved for deliberate form audits.
Fantasy rehearsal of un-owned skills	Imagining a professional's stroke from the inside.	Forward model has no data; generic prediction; noise deposited into the schema.	Image only own best executions; acquire the physical components first, then rehearse them.
Imagery replacing physical work (healthy athlete)	Over-sold tool; convenience.	Smaller gains than physical practice; decalibration between feel and reality.	Interleave at 1:2–1:3; cap standalone sessions; treat imagery as multiplier, never substitute.
Marathon sessions / attention drift	Volume culture applied to an attention-limited resource.	Junk reps below the vividness threshold; consolidation of gray, corrupted images.	6–15 minute blocks; per-rep scoring; hard stop when vividness < 3 or controllability < 3.

6. Diagnostic Diagram

PANEL A — THE CEREBELLAR LOOP: EXECUTION vs. IMAGERY

  EXECUTION                              IMAGERY
  ─────────                              ───────
  Motor command u                        Motor command u (weakened)
      │                                      │
      ├──────────► efference copy ──► CEREBELLAR FORWARD MODEL
      │                                  f(ŝ, u; θ) ──► predicted
      ▼                                  state ŝ, felt & seen
  SPINAL GATE OPEN                           │
      │                                      ▼
  Muscles fire, ball flies              SPINAL GATE CLOSED
      │                              (H-reflex suppressed;
      ▼                              subliminal EMG only)
  Sensory re-afference                      │
      │                                      ▼
      └──────────► COMPARE ◄──────── intended goal state
                    │                        (no ball needed)
                    ▼
              ERROR → schema update Δθ
              (climbing-fiber teaching signal;
               in imagery, prediction-vs-intent)

PANEL B — SHARED CIRCUITRY, GATED OUTPUT (schematic activation)

  Premotor cortex     ████████████  ██████░
  SMA                 ████████████  █████░░
  Parietal cortex     ███████████   ██████░
  Basal ganglia       ██████████    ████░░░
  Cerebellum          ████████████  ███████
  Primary motor ctx   ████████████  ██░░░░░
  Spinal output       ████████████  ░░░░░░░  ← the gate
                    (execution)   (imagery)

  The rehearsal recruits the machine; the gate spares the body.

Reading the diagram: Panel A shows why imagery trains anything: the command, the efference copy, the forward model, the prediction, and the comparison-error-update loop are all shared with execution — only the spinal gate differs. The schema ($\theta$) is updated by the same error signal whether the ball was real or predicted. Panel B shows the same point as activation. The training stimulus is the rehearsal of the computation, not the movement of the muscle — which is exactly why the repetition is free, and exactly why its content must be policed.

7. Video Demonstration

[TVZhH9zL3Ds]

Placeholder: insert a two-part demonstration. Part 1 — the protocol: athlete performing Step 1 reference calibration (own match footage), Step 2 PETTLEP stack assembly on court in kit with racket, Step 3 scored simulation reps with on-screen vividness/controllability logging, Step 4 error protocol executed live. Part 2 — the mechanism: simple motion-graphics walkthrough of Panel A (command → efference copy → cerebellar forward model → prediction → spinal gate), with an H-reflex/MEP overlay from laboratory footage, and a split-screen of an imagined vs. executed serving ritual timed against a stopwatch to show duration fidelity.

8. Cross-Domain Synergy

Article 041 (Quiet Eye Fixing Visual Anchors Before Impact) and Article 050 (Temporal Perception and Slower Ball Tracking in Flow States): the visual anchor belongs in the imagery script — rehearsing the fixation point trains gaze routine and motor program together — and real-time imagery is temporal-perception training: the athlete who rehearses at true speed owns a faster subjective clock.
Article 044 (Amygdala Hijack Mitigation under Match Pressure): imagery with the emotion axis loaded is exposure training — pressure scenarios rehearsed in simulation arrive on court pre-degraded.
Article 045 (Subconscious Motor Program Recruitment — Self 1 vs. Self 2): imagery is Self 2's rehearsal language — non-verbal, kinesthetic, subcortical — which is why verbal self-talk cannot substitute for it.
Article 047 (Pre-Point Routines and Sympathetic Modulation): the between-point imagery micro-routine and the physiological reset share one ritual window; this article supplies its cognitive content.
Article 048 (Neuro-Priming Protocols for Explosive First-Step Readiness): priming for the body's readiness; this article primes the brain's program selection — two windows, one warm-up.
Article 051 (Neural Myelination through High-Density Precision Repetitions): imagery adds coincident firing without movement — precision repetitions for the consolidation machinery, at zero joint cost.
Article 053 (Cognitive Load Reduction through Automated Tactical Heuristics): imagery of tactical patterns (opponent position → shot selection) automates the decision layer, not just the stroke.
Article 060 (BDNF and Motor Skill Acquisition): the amoral-consolidation principle is shared — the simulator strengthens what it runs, so the imagery script is a plasticity request and must be designed like one.
Article 069 (Subconscious Target Projection): target imagery is the outcome layer of the simulation — this article supplies the process imagery that delivers to it.
Article 075 (Tactical Between-Point Rituals) and Article 166 (Sleep Architecture and Growth Hormone Peak Tuning): the deployment windows — the between-point routine and the pre-sleep replay are where a trained simulator pays its highest dividends.

9. Self-Assessment Matrix

#	Assessment Question	Yes	No
1	Do you run structured, scored imagery sessions (script, ratings, stopwatch) rather than ad-hoc visualization?	☐	☐
2	Is your default rehearsal internal-perspective and kinesthetic, with external perspective used only for form audits?	☐	☐
3	When you time your imagined serving ritual against a stopwatch, does it land within ~10% of the real duration?	☐	☐
4	Do you interleave imagined reps with physical reps (about 1:2–1:3) inside technical blocks?	☐	☐
5	After an error, do you run the stop–reset–highlight–re-run protocol instead of replaying the miss?	☐	☐
6	Do you replay the session's best 3–4 executions in a 5-minute block before sleep on technical days?	☐	☐
7	Can you feel the difference in your body (grip pressure, leg load) between a vivid rep and a gray one — and do you end sets when vividness drops?	☐	☐
8	On injury or travel days, do you run a 10–15 minute maintenance session on your key pattern?	☐	☐

Scoring: 7–8 "Yes" — the simulator is deployed as a training tool; refine scripts and transfer-test. 4–6 — mixed profile; fix structure first (items 1, 2, 5 — script, seat, and error protocol cost nothing and gate everything). 0–3 — imagery is currently daydreaming; run the full Section 3 protocol for four weeks with the Section 4 metrics before crediting or discrediting the tool.

10. Printable Practice Card: The Simulator Protocol

Session goal: run the right program, at the right speed, from the right seat — and log every rep.

Block	Drill / Action	Dose	Cue
A — Calibrate (5 min)	Watch 3–5 clips of own best execution of the target pattern; define the feel target in writing	1 pass full speed, 1 slow-mo audit, 1 eyes-closed afterimage	"Steal from your own best day."
B — Stack (3 min)	Assemble the PETTLEP scene: kit on, racket in hand, court geometry, score, emotion	Before every set	"The body is part of the input."
C — Simulate (8 min)	Full situational reps: read → split → load → strike → outcome hold 2 s; score vividness + controllability per rep	3 sets × 5–8 reps; 30–60 s between sets	"Real time, from inside, with feeling."
C — Simulate	Error protocol on any corrupt rep: stop → exhale → 3-s clean highlight → re-run	As needed	"Never replay the miss."
D — Deploy (5 min)	Interleave: 1 imagined rep per 2–3 physical reps in the day's technical block; post-block replay of best 3–4 reps; pre-sleep 5-min replay	Attached to every technical day	"Prime it, interleave it, sleep on it."

Weekly frequency: 3–5 scored imagery sessions (6–15 min) + interleave on every technical day + between-point micro-routine in matches. Progression gate: do not add imagery volume until duration fidelity is within ±10% and mean vividness is ≥ 4/5 across two consecutive weeks — a gray simulator run twice as long is still a gray simulator. If a 4-week block shows no transfer to the target test, audit the script's task specificity and the seat (internal-kinesthetic) first.

Cross-references: ART-041, ART-044, ART-045, ART-047, ART-048, ART-050, ART-051, ART-053, ART-060, ART-069, ART-075, ART-166. Pillar II: Neuro-Athletics & Cognition — TennisKB 200-Article Knowledge Base.