Investigating Surprise Signals in the Anterior Insula

NCT ID: NCT05997758

Last Updated: 2024-05-08

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 50 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-01-15
• Study Completion Date: 2025-12-31

Brief 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. 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.

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.

Conditions

Drug Resistant Epilepsy; Healthy

Study Design

• Observational Model Type: CASE_CONTROL
• Study Time Perspective: CROSS_SECTIONAL

Study Groups

Patients

Patients 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

SEEG stimulation

Intervention Type: OTHER

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 task

Intervention Type: BEHAVIORAL

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.

Subclinical

Healthy individuals who match the clinical population in age and level of education.

N = 40

Adaptation task

Intervention Type: BEHAVIORAL

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.

Interventions

SEEG stimulation

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.

Intervention Type: OTHER

Adaptation task

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.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• 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

Exclusion Criteria

• 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.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Geneva, Switzerland

OTHER

Sponsor Role: collaborator

University Hospital, Geneva

OTHER

Sponsor Role: lead

Responsible Party

Fabienne PICARD

Prof

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Service de Neurologie, Dpt des Neurosciences cliniques HUG

Geneva, , Switzerland

Site Status: RECRUITING

Countries

Switzerland

Central Contacts

Fabienne Picard, MD

Role: CONTACT

Fabienne.Picard@hcuge.ch

+41 22 372 5258

Nina Sooter

Role: CONTACT

nina.sooter@unige.ch

+41 79 6791 949

Facility Contacts

Fabienne Picard, MD

Role: primary

Fabienne.Picard@hcuge.ch

+41 22.3725.258

References

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.

Reference Type: BACKGROUND

PMID: 26850528 (View on PubMed)

Other Identifiers

2022-02041

Identifier Type: -

Identifier Source: org_study_id