The cross-linguistic inner-speech dataset of the BINGO (Brain Imagined-Speech Communication) project at CERTH is one of the two EEG datasets the project releases on its website. On each trial a participant saw one of 15 matched nouns, in Greek or in English, held it in memory through a countdown, and then said it silently during a 1.5-second inner-speech window; each item was repeated ten times, in fully randomised order. The project's public deliverable D3.1 describes the protocol and states that the same preprocessing, including artifact removal, was applied to both released datasets. The source states no licence. Only its complete subject records are used here.
Also known asBINGO (Brain Imagined-Speech Communication) · BINGO cross-linguistic inner speech elicitation dataset · BINGO Dataset 2 · D3.1 – The BINGO Benchmarking Framework
Relative band power + ridge classifier · Trained on Greek, tested on Greek · a subject field left out
6.4% (5.8%–6.9%)
Relative band power + ridge classifier · Trained on Greek, tested on English · a subject field left out
6.6% (5.5%–7.6%)
Relative band power + ridge classifier · Trained on English, tested on English · a subject field left out
6.7% (5.8%–7.6%)
Relative band power + ridge classifier · Trained on English, tested on Greek · a subject field left out
7.1% (6.2%–7.9%)
0%25%50%75%100%
Balanced accuracy, 4 configurations. Dot: the estimate; line: 95% interval; dashed line: chance level where the payload records one.
Method
Condition
Metric
Value
People
Relative band power + ridge classifier
Trained on Greek, tested on Greek · a subject field left out
Balanced accuracy
6.4%5.8%–6.9%Top-3 accuracy 19.1%, against its prior of 20.0%.
17 subject fields as the source defines them, not proven distinct people
Relative band power + ridge classifier
Trained on Greek, tested on English · a subject field left out
Balanced accuracy
6.6%5.5%–7.6%Top-3 accuracy 21.0%, against its prior of 20.0%.
17 subject fields as the source defines them, not proven distinct people
Relative band power + ridge classifier
Trained on English, tested on English · a subject field left out
Balanced accuracy
6.7%5.8%–7.6%Top-3 accuracy 19.9%, against its prior of 20.0%.
17 subject fields as the source defines them, not proven distinct people
Relative band power + ridge classifier
Trained on English, tested on Greek · a subject field left out
Balanced accuracy
7.1%6.2%–7.9%Top-3 accuracy 19.6%, against its prior of 20.0%.
17 subject fields as the source defines them, not proven distinct people
Relative band power + ridge classifier
Across languages minus within, the mean over both training languages
Paired difference
+0.3 pp−0.6–+1.3 ppThe interval spans zero: no superiority or equivalence between languages, and no significance test.
17 subject fields as the source defines them, not proven distinct people
Every direction is close to the 15-class prior. A negative result for this one baseline in this setting: it does not show that inner speech cannot be decoded by other methods. The intervals are approximate and descriptive, from overlapping leave-one-field-out fits. Outside every leaderboard and model ranking.
Delivered signals, as the project describes them (BINGO deliverable D3.1, version 2.0): the same preprocessing for both of its released datasets — band-pass and notch filtering, Artifact Subspace Reconstruction (ASR) and FORCe removal of ocular and muscle artifacts — and then segmentation into trials. The signals analysed here were therefore artifact-cleaned on the continuous recordings before any trial was cut. As the project states it; not re-verified against the delivered file.
Source and licence
BINGO cross-linguistic inner-speech dataset
CreditBINGO (Brain Imagined-Speech Communication) project, CERTH · cross-linguistic inner-speech EEG dataset, https://bingo-project.gr/datasets/; no licence is stated by the source. Documentation: Fotis P. Kalaganis, Kostas Georgiadis, Maria Kyrou, Spiros Nikolopoulos and Ioannis Kompatsiaris, D3.1 – The BINGO Benchmarking Framework, version 2.0, public deliverable (2025), https://bingo-project.gr/download/397. Derived analysis by BCI Report; not endorsed by the authors.
BCI Report does not redistribute any recording. These are aggregate measurements computed by BCI Report from data whose source states no licence; no right to reuse the data is implied.
Ethics and consent, as the source states them
Ethics approval: No ethics-approval reference is published by the source.
Informed consent: The project’s public deliverable D3.1, version 3.0, states that each participant signed a consent form before the sessions. It says so for the project’s 20-participant NATO-alphabet dataset, recorded in the same CERTH laboratory; the cross-language dataset’s own documentation, D3.1 version 2.0, has no ethics or consent statement.
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