MOTOR-IMAGERY EEG

Decode imagined movement
from recorded
brain signals

This experiment classifies EEG recorded while people imagined moving their left or right fist, letting you inspect each prediction and see how confidence affects whether the model sends a cursor command

—people after data checks
—usable EEG trials
—people held out

PUBLIC EEG · PHYSIONET · 160 Hz

01 / DECODING STUDIO

EEG decoding

Run the model on a held-out recording to inspect its prediction and confidence

THE RECORDING

Three-second EEG recording

HELD-OUT EEG
Cued imagery: ——Download this signal ↓

Change the conditions

Test the same signal with a controlled disturbance

These repeatable disturbances are applied after preprocessing to test specific sensitivities, without simulating every real headset failure

THE DECISION

Ready to decode

— ms
Left —Right —

Choose a trial and run the decoder

Predictions below this confidence level produce no command

COMMAND REPLAYWaiting
L
R

A simulation using recorded EEG, with no headset or physical device connected

MODEL SENSITIVITY

Which channels change the answer?

LIVE OCCLUSION

Each electrode is set to zero in turn to measure the change in the model’s probability of right-fist imagery

The schematic shows model sensitivity to channel removal, which cannot establish where a thought originates in the brain

THE RHYTHMS

Power across frequencies

Alpha / mu · 8–13 Hz Beta · 13–30 Hz

Average power across the displayed channels, with the filter informed by motor-imagery research [1]; the spectrum alone cannot identify the imagined movement

02 / THE EVIDENCE

Evaluation on unseen participants

Participants remain separate across training, validation and testing so the evaluation measures generalisation to unfamiliar people

Selected model · held-out people—

Participant-macro balanced accuracy

When the model accepts a command—

At the declared fallback confidence threshold

Chance-level reference50%

Balanced accuracy for this two-class task

FOUR FIXED CANDIDATES

Model comparison

Model Validation Test

Both columns report participant-macro balanced accuracy for every candidate, with the serving model selected using validation results only

ACCURACY AND COVERAGE

Confidence thresholds

Each point represents a different confidence threshold; high thresholds retain fewer trials, making the resulting accuracy less certain, so this exploratory chart should be interpreted alongside coverage

PARTICIPANT VARIATION

Results by participant

Each bar includes all eligible test trials for one participant, while the demonstration uses their first six valid trials without selecting for successful predictions

CONTROLLED STRESS TESTS

Signal perturbation analysis

The selected model remains frozen while these disturbances measure sensitivity under specific conditions, without establishing suitability for a wearable or assistive device

Inspect calibration, confusion matrix and data exclusions +

Probability calibration

Every prediction, including errors

Rows: recorded label · Columns: model prediction · All test trials before abstention

Data quality audit

Full provenance and exclusions ↗

03 / RESEARCH

Methods and interpretation

01

Research question

IntentLab investigates whether models can distinguish cued left and right fist imagery in previously unseen participants, using a fixed EEG window and allowing uncertain predictions to be rejected.

The comparison includes common spatial patterns [4] and a compact convolutional model inspired by EEGNet [5], with selection based on validation participants.

02

Interpretation

The selected model reaches 61.1% participant-macro balanced accuracy, although its confidence threshold fails the validation target for reliable control, as assessed in the research report.

Visual cues, eye movements and muscle artefacts may contribute to the predictions, so classification performance alone cannot demonstrate that the model has isolated motor intention.

03

Further evaluation

A stronger evaluation would use repeated participant splits, an independent dataset and causal filtering for streaming signals, with a new untouched test set for each subsequent development.

The present results are restricted to a two-class, cued motor-imagery task and provide no evidence for decoding arbitrary thoughts, reconstructing dreams or measuring consciousness.