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Drug Resistant EpilepsyNCT05997758

Investigating Surprise Signals in the Anterior Insula

An observational study of Drug Resistant Epilepsy and Healthy, run by University Hospital, Geneva at 1 site in Switzerland.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

The investigators propose a behavioral experiment with SEEG recording and stimulation, to both confirm the role of a brain region known as the anterior insula in identifying surprise, and disambiguate between competing principles behind adaptation: optimizing and satisficing. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Drug Resistant Epilepsy, Healthy
What is being tested?
SEEG stimulation and Adaptation task
How many people
50 participants
Where
1 siteSwitzerland
Study dates
15 Jan 2024to Dec 2025
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: Patients who suffer from potentially surgically remediable drug-resistant focal epilepsy and require evaluation with intracranial stereo-EEG electrodes and have them implanted in the anterior insula hospitalized at the Hôpitaux Universitaires Genève.

Who may be able to join

  • 18 years or older
  • Fluent in French or English
  • Patient who suffers from potentially surgically remediable drug-resistant focal epilepsy
  • Patient who requires evaluation with intracranial stereo-EEG electrodes and has them implanted in the anterior insula
  • Patient who is able and willing to provide informed consent

Who cannot join

  • Severe concomitant psychiatric disease or major psychological distress
  • Patients who have an implanted stimulation device (e.g. pacemaker, defibrillator, neurostimulator)
  • Intellectual/neurological/psychiatric deficiencies* or inability to understand or follow the procedure
  • Visual/motor deficiencies which could affect task performance
  • The presence of seizures during routine clinical stimulation of insular electrodes
  • Failure to complete the pre-experiment task training
  • As determined by their clinical evaluation.

Trial locations and contacts

1 site in 1 country.

Switzerland1 site, 1 recruiting
  • Service de Neurologie, Dpt des Neurosciences cliniques HUG

    Geneva, 1205

    Fabienne Picard, MD, +41 22.3725.258, Fabienne.Picard@hcuge.ch

    Recruiting

Other trials in Switzerland

About this study

Official title: Investigating Surprise Signals in the Anterior Insula in Epilepsy Patients With Stereoelectroencephalography Recording

The investigators propose a behavioral experiment with SEEG recording and stimulation, to both confirm the role of a brain region known as the anterior insula in identifying surprise, and disambiguate between competing principles behind adaptation: optimizing and satisficing. Optimizers continue to learn and adapt if performance can be improved, while satisficers are satisfied with a good enough performance and will cease adapting once that is reached.

To study surprise signals in the anterior insula, a brain structure where these signals have been very prominent, the investigators will employ an experiment with subjects who are under SEEG (stereoelectroencephalogram) recording, that is, recording from electrodes which have been surgically implanted in the brain. These recordings will be done as patients perform a task where they try to anticipate the movements of a target on a line in two different learning environments (conditions). The experimenters will then determine whether these signals reflect surprise relative to past engagement with the environment, or surprise that reveals that the agent no longer feels in control because uncertainty is not in line with the reference model. If evidence is consistent with the former, adaptation reflects traditional reinforcement and aims at optimizing behavior. If evidence instead is consistent with the latter, behavior is guided by a prior model (a reference model) and behavior is satisficing.

Read more

An fMRI study by d'Acremont and Bossaerts provides initial evidence that activation in the anterior insula supports the satisficing hypothesis, however it lacks the temporal granularity to completely rule out optimizing. In the current project, the investigators propose to use the higher time resolution of SEEG recordings to confirm these findings and reject the optimizing hypothesis.

Additionally, stimulations of the anterior insula during a subset of trials will be used to determine whether insular activation following surprise signals and preceding changes in behavior (learning) is merely correlational or in fact causal. Stimulation will allow us to determine to what extent the subjects' sense of control and subsequent behavior can be influenced in accordance with surprise-based modeling of behavior.

The cohort for this study will be patients with drug-resistant, focal epilepsy and who are hospitalized at the Hôpitaux Universitaires de Genève (HUG) for pre-surgical evaluation of their epilepsy using SEEG. The protocol will run in parallel with the patients' clinical procedures.

Being tested
SEEG stimulation, Adaptation task
Medical subject headings
Drug Resistant Epilepsy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • SEEG stimulationOther

    Electrodes already implanted in patient's anterior insula will be stimulated below the patient-specific threshold at which a seizure was induced. This stimulations will coincide with certain trials in the adaptation task.

  • Adaptation taskBehavioural

    Participants will perform a task that requires them to learn and correctly respond to outliers of two sorts; inconsequential outliers, which require no action, and outliers that are relevant to the course of stimuli and outcomes in future trials, requiring adaptive action.

Study groups in NCT05997758
Study groupRoleWhat they receive
PatientsPatients who suffer from potentially surgically remediable drug-resistant focal epilepsy and who require evaluation with intracranial stereo-EEG electrodes and have them implanted in the anterior insula. N = 10
Receives: Other: SEEG stimulation; Behavioral: Adaptation task
SubclinicalHealthy individuals who match the clinical population in age and level of education. N = 40
Receives: Behavioral: Adaptation task

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Bias adjustment -- non-stimulation trials (behavioral, numerical)

    Subjects' choices, measured as the degree of bias correction they employ (a numerical value typically between 0 and +/-3) during outlier trials and the trials immediately following them. These will be quantitatively compared between conditions using Bayes-optimal choices and choices as predicted by Model-Reference Based Adaptive Control.

    Measured: Up to 2500 ms after stimuli presentation. All data collected during eight 5-minute sessions on the same day

  2. Bias adjustment -- stimulation trials (behavioral, numerical)

    Subjects' choices, measured as the degree of bias correction they employ (a numerical value typically between 0 and +/-3) during stimulation trials (both outlier and non-outlier trials). These will be quantitatively compared to choices on the same trial types without stimulation.

    Measured: Up to 2500 ms after stimuli presentation. All data collected during four 5-minute sessions on the same day

  3. SEEG-ERP--non-stimulation trials

    Event-related potentials (ERPs) extracted from subjects' stereoelectroencephalographies from intercranial electrodes implanted in the anterior insulae. ERPs will be averaged across the time series and t-statistics will be computed for effect of condition (outlier type).

    Measured: Up to 2500 ms after stimuli presentation. Averaged over all trials for each task condition. All data collected during 8 5-minute sessions on the same day

  4. SEEG-TF--non-stimulation trials

    The stereoelectroencephalographies from intercranial electrodes implanted in subjects' anterior insulae will be used for time frequency (TF) analyses. Time series components will be extracted for multiple frequencies and t-statistics of the effects of condition (outlier type) will be computed for each frequency.

    Measured: Up to 2500 ms after stimuli presentation. Averaged over all trials for each task condition. All data collected during 8 5-minute sessions on the same day

Secondary outcomes (1)
  1. Reaction time (numerical)

    Comparison of subjects' response times to stimuli

    Measured: Up to 2500 ms after stimuli presentation. All data collected during 8 5-minute sessions on the same day

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Aug 2023
  2. Study start15 Jan 2024
  3. Primary completionJul 2025 (estimated)
  4. Study completionDec 2025 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case-control
Time perspective
Cross-sectional
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05997758
Sponsor's protocol ID
2022-02041
Status last verified
May 2024
First submitted
1 Jun 2023
Last updated
8 May 2024
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • d'Acremont M, Bossaerts P. Neural Mechanisms Behind Identification of Leptokurtic Noise and Adaptive Behavioral Response. Cereb Cortex. 2016 Apr;26(4):1818-1830. doi: 10.1093/cercor/bhw013. Epub 2016 Feb 4.

    PubMed 26850528

Questions about this trial

What is this clinical trial studying?

An observational study of Drug Resistant Epilepsy and Healthy, run by University Hospital, Geneva at 1 site in Switzerland.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: status not confirmed, as of the sponsor's last update on 8 May 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

Contact Fabienne Picard, MD (+41 22 372 5258, Fabienne.Picard@hcuge.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Bias adjustment -- non-stimulation trials (behavioral, numerical) (time frame: Up to 2500 ms after stimuli presentation. All data collected during eight 5-minute sessions on the same day). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05997758, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2024; AzTrials last refreshed its copy on 7 Nov 2026.

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