Flexible Representation of Speech: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Flexible Representation of Speech (NCT05209386), a na na study. The primary outcome is Supratemporal Neural Response to Change in Acoustic-Phonetic Dimensions.

2. Clinical Question

The research focuses on speech processing in the supratemporal plane, a region that includes Heschl's gyrus, the planum polare, and the planum temporale. The registry summary describes this area as relevant to rapid analysis of acoustic information and its mapping to linguistic representation. Direct study of neural activity in this region is difficult with non-invasive scalp EEG, while this study uses access to sEEG recordings obtained during clinical monitoring.

The question is exploratory and concerns neural encoding during listening tasks. It is not a comparison of treatments for epilepsy. The primary outcome counts channels meeting a criterion for significant encoding; it does not directly measure a clinical outcome or establish how a participant performs outside the recorded task. The registry record does not report the observed channel count or the statistical result for this primary question.

3. Trial Design

The registry lists this as a completed, single-group study sponsored by the University of Pittsburgh. The study began on 2022-05-02, and its primary completion date is 2024-07-01. The recorded enrollment is 48. The phase is listed as NA, and allocation is also listed as NA. Masking is recorded as none.

Participants were patients undergoing invasive neurophysiological monitoring with sEEG and clinically necessary electrode placement in the supratemporal plane. The arm description says participants were recruited through the principal investigator’s clinical practice and that all participants completed the same behavioral response paradigms. This setup reflects access to neural recordings during clinical monitoring, rather than assignment to contrasting treatment groups.

The intervention is named Dimension-Based Statistical Learning and classified as behavioral. During sEEG-EEG recording sessions, which could last up to 3 hours total, participants listened to acoustic stimuli with manipulated dimensions including F0 and VOT. The primary outcome description specifies the count of temporal lobe channels with significant encoding of change in F0 while VOT is held constant.

The registry lists 6 outcome measures and 6 analyses, but their full results and analysis details are not reported in the registry record. Neural data from 3 participants were excluded because of noise contamination. The number of participants included in each analysis is not reported in the registry record.

The design does not support a randomized between-group treatment comparison: there is a single group and no comparator arm. The study instead addresses neural response patterns observed during a behavioral task. Details such as eligibility criteria beyond the described clinical monitoring context, the exact recruitment flow, and the statistical analysis plan are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Before assignment: As there is only a single experimental group in this study, all enrolled patients were assigned to Arm 1 (Patient Participants).

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Neural data from 3 participants was contaminated by noise and was thus excluded from analysis.

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Supratemporal Neural Response to Change in Acoustic-Phonetic Dimensions, measured over During sEEG-EEG recording sessions, up to 3 hours total.

The primary outcome is the count of sEEG channels demonstrating significant encoding of an acoustic-dimension change. The unit is sEEG channels, and the registry classifies the outcome as a count of units. Neural activity is measured through simultaneous EEG-sEEG monitoring in the supratemporal plane, using high-gamma band activity in the electrical signal.

For the reported primary measure, participants listen to acoustic stimuli while F0 changes and VOT is held constant. The endpoint is therefore a channel-level count based on whether the recorded neural signal meets the study’s significance criterion for encoding that change. The registry record does not report the exact significance criterion, the observed count, or the statistical result.

This measure is used to describe whether and how broadly neural responses in the recorded channels reflect a change in an acoustic feature. A channel count can be informative about the distribution of detectable encoding across recorded sites, but it is not itself a direct measure of clinical benefit, speech understanding in daily life, or a treatment effect. It also does not by itself describe the size or precision of each channel’s response.

The registry describes a broader aim involving both F0 and VOT and shifts in listening context. However, the primary outcome description specifically defines the reported count with F0 changing while VOT is constant. Other outcome measures are listed, but their full definitions and numerical results are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the outcome’s unit and structure. Here, the primary measure is a count of sEEG channels, not a continuous score or a participant-level clinical event. Each counted channel is classified according to whether it demonstrates significant encoding of the specified acoustic change. The registry record identifies the outcome as a count of units, but does not report the observed count, the number of channels evaluated, or the statistical model used to produce the result.

What does a channel count describe?

In general, a count describes how many units meet a defined condition. In this study, the units are channels and the condition is significant encoding of change in F0 while VOT is held constant. The count can summarize the spread of detectable responses across recorded channels. It does not, on its own, show the magnitude of the response in each channel, the consistency of responses across participants, or the precision of the estimated count.

In general, interpreting a count also requires a clear account of the units eligible to be counted. For this outcome, the record does not state how many channels were assessed, how channels were assigned to the temporal lobe category, or what threshold determined whether a channel demonstrated significant encoding. Without these details and the numerical outcome, readers cannot assess the proportion of assessed channels that met the criterion or compare the count with another condition.

Why does the analysis unit matter?

In general, observations from the same participant may be related rather than independent. Multiple channels recorded from a participant can share characteristics because they come from the same person and recording session. Treating every channel as independent when there is clustering can understate uncertainty. Appropriate analysis may need to account for participant-level grouping or other dependencies, depending on the data and research question. The statistical model and handling of this structure are not reported in the registry record, so it is not possible to determine how dependence among channels was addressed.

In general, count data can have variability that differs from the assumptions of a simple Poisson model. Over-dispersion means that the observed variability is greater than that model expects; ignoring it can make uncertainty estimates too narrow. Other features, such as many zero counts or variation in the number of channels recorded per participant, may also affect model choice. These are general considerations for count outcomes, not reported features of this study. The record does not identify a count model or describe how variability was assessed.

What does statistical significance mean?

In general, a significance criterion is a rule for deciding whether observed data are sufficiently inconsistent with a specified null model under the chosen analysis. A channel being classified as significant does not itself quantify the size of its response, and statistical significance is not a measure of clinical importance. The registry record does not report the channel-level test, the threshold used, or how tests across channels were handled. It is therefore not possible to assess the classification procedure from the registry entries.

In general, confidence intervals communicate the uncertainty around an estimate by giving a range of values compatible with the data and statistical model. A confidence interval for a count or related effect would help readers understand precision, but none is reported for the primary endpoint in the registry record. A p-value, if reported, would address a different question and would not replace an effect estimate or interval.

How should planning calculations be read?

The planning assumptions associated with the record describe an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two hypothetical arms, and a normal approximation. Such an illustration is not the design of this single-group study and is not observed power. It does not show how likely the completed study was to detect a result, nor does it establish the validity or precision of the reported outcome. The number of participants per arm for a planning scenario is not reported in the registry entries.

In general, sample-size calculations depend on a target effect, variability assumptions, a chosen error rate, and the analysis design. An illustration based on a fraction of an observed effect is a planning aid rather than a retrospective measure of the study’s success. The registry record does not report a protocol-based sample-size justification for this study, so none should be inferred from the planning assumptions.

What can be concluded from the listed analyses?

The record lists 6 outcome measures and 6 analyses. In general, when multiple outcomes or tests are examined, the chance of at least one apparently significant result can increase if no multiplicity approach is used. Adjustments or a prespecified hierarchy may address that concern, but the registry record does not report whether either was used. The number of listed outcomes alone does not establish that every possible comparison was conducted or that a particular multiplicity correction was required.

Because the numerical endpoint result, uncertainty estimates, analysis model, and test details are not reported in the registry record, the statistical evidence cannot be reconstructed from the outcome definition alone. The record supports a description of what was intended to be measured; it does not support an independent assessment of the estimated effect or its precision.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures and 6 analyses. It does not report a prespecified hierarchy of outcomes, a multiplicity adjustment, or how the analyses were selected and interpreted. In general, testing multiple outcomes can increase the chance of at least one statistically significant result under a null setting if tests are treated as independent decisions without adjustment. Whether that concern applies, and how it was addressed, cannot be determined from the registry record.

Neural data from 3 participants were excluded from analysis because of noise contamination. This is an explicit reason for exclusion, but the record does not report the number of participants included in each analysis, the number of usable channels, or whether all outcomes used the same data. It also does not describe missing-data methods, criteria for excluding individual channels, or sensitivity analyses. The final analysis population is therefore not reported in the registry record.

In general, exclusions can affect an estimate if the probability of unusable data is related to the neural response or other study characteristics. That possibility should not be assumed to have occurred in this study, but the record does not provide enough information to evaluate it. A clear account of data availability and exclusions by outcome would help readers understand which recordings contributed to each result.

The study has a single group, but the record does not detail the analysis populations or any distinction between participants enrolled, recorded, and included in each analysis. No additional population definitions or missing-data procedures are reported in the registry record.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

The registry lists 48 patient participants at risk for serious adverse events and reports 0 affected in that category. It also lists 48 at risk for other adverse events and reports 0 affected. Deaths are recorded as 0. No serious adverse event terms are listed.

These figures are registry entries for the reported safety categories; they should not be read as proof that the monitoring procedures or study activities carry no risk. The study involved patients undergoing clinically necessary sEEG monitoring, and the arm description says electrode placement was clinically indicated. The record does not report a detailed account of event definitions, collection procedures, event severity assessment, or the period during which adverse events were monitored.

The safety figures are distinct from the neural analysis exclusions: the record says neural data from 3 participants were excluded because of noise contamination. That is a data-quality statement, not an adverse event. The registry record does not provide further detail about adverse-event ascertainment or whether the reported safety categories cover every event monitored during the study.

12. What the Result Does, and Does Not, Mean

This study addresses how neural activity recorded in the supratemporal plane relates to acoustic features of speech. Its primary endpoint is a count of channels demonstrating significant encoding of a change in F0 while VOT is held constant. The registry summary places that measure within a broader exploratory aim: understanding neural responses to acoustic-phonetic dimensions and how listening context may alter perceptual weighting.

The record does not report the numerical value of the primary endpoint, a confidence interval, a p-value, or a detailed statistical analysis. It is therefore not possible to say from the registry entries how many channels met the criterion, how precise the estimate was, or whether the result was consistent across participants. Completion of the study does not supply that missing result.

The findings, if interpreted from a full analysis, would concern neural recordings made during a behavioral listening task in a clinically monitored population. A channel-level count does not by itself establish how speech is processed in all people, how well a person understands speech in everyday settings, or whether any clinical intervention changes an outcome. No treatment efficacy question is answered by the described single-group design.

The record also does not report the full results for the other listed outcome measures or the methods used to account for multiple analyses. Neural data from 3 participants were excluded because of noise, while the analysis population for each endpoint is not reported. These omissions limit interpretation of how broadly the recorded results apply and how precisely they estimate the neural response.

Overall, the registry record describes a research question and an outcome definition, rather than a result that can be quantitatively evaluated. The endpoint is relevant to the stated mechanistic aim, but the registry entries do not establish the direction, magnitude, or certainty of the observed neural response.

13. Why This Trial Matters Statistically

This study raises statistical questions that are important for research using intracranial neural recordings. The primary endpoint counts channels, while recordings are collected from participants. Those levels of observation are not interchangeable: multiple channels from the same person may be related. Statistical methods need to reflect the structure of the data if uncertainty is to be interpreted appropriately. The registry record does not report the model or how dependence among channels was handled.

It also illustrates why an outcome definition is not enough to interpret an analysis. A count of channels meeting a significance criterion depends on which channels were assessed, how the criterion was defined, and how multiple channel-level tests were managed. Those details, as well as the observed count and its uncertainty, are not reported in the registry record.

The study’s single-group design is suited to describing responses recorded during a task, but it does not create a randomized contrast between treatment groups. The design distinction matters: a neural encoding measure should not be framed as a treatment comparison or clinical efficacy result when no comparator arm is recorded.

Finally, the documented exclusion of noisy neural data from 3 participants emphasizes the importance of transparent analysis populations. Reporting which recordings contributed to each endpoint, alongside the treatment of missing or unusable data, helps readers assess the scope and precision of neural findings. The registry record states the exclusion reason but does not provide the full analysis flow.

14. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The numerical primary outcome and its uncertainty are not reported in the registry record. Consequently, the observed number of channels demonstrating significant encoding, the precision of that estimate, and its compatibility with alternative explanations cannot be assessed. The record also does not describe the threshold for declaring a channel significant or the number of channels evaluated.

Neural data from 3 participants were excluded because of noise contamination, but the number of participants included in each analysis is not reported. The record does not describe how noisy channels or other missing data were handled, whether exclusions were limited to particular outcomes, or whether analyses were repeated under alternative assumptions.

The primary endpoint focuses on F0 change with VOT held constant, while the overall research aim also concerns VOT, perceptual weighting, and changes in listening context. The registry entries do not provide the full outcome definitions or results needed to evaluate those broader questions. They also do not report the statistical model, treatment of dependence among channels, multiplicity procedures, or a protocol-based sample-size justification.

The study is single-group and has no comparator arm. Therefore, its design does not permit a randomized between-group comparison. Participants were patients undergoing clinically necessary sEEG monitoring, so the recordings arise in a specific clinical context; the registry record does not establish how broadly results would generalize beyond that context.

The registry lists no serious adverse event terms and reports zero affected in the listed serious and other adverse event categories, but event definitions and ascertainment details are not reported. These limitations concern what can be concluded from the registry record and do not establish that an unreported method or result was absent from the underlying research.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Flexible Representation of Speech — NCT05209386.
• Registry record last updated 2025-09-08; status last verified 2025-08.
• Results first posted 2025-09-08.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

NCT05209386, titled “Flexible Representation of Speech,” is recorded as a completed single-group study sponsored by the University of Pittsburgh. The study began on 2022-05-02, with primary completion on 2024-07-01, and recorded enrollment of 48. It concerns patients with epilepsy undergoing clinically necessary sEEG monitoring with electrode placement in the supratemporal plane.

Participants completed the same behavioral response paradigms. The primary outcome is the count of temporal lobe sEEG channels demonstrating significant encoding of change in F0 while VOT is held constant. The record lists 6 outcome measures and 6 analyses. Neural data from 3 participants were excluded because of noise contamination.

The observed primary outcome, its uncertainty, the analysis model, and the final analysis population are not reported in the registry record. The design has no separate comparator arm, so the record describes a neural-response study rather than a randomized treatment comparison.