Skip to main content
OpenTrials
Recruiting

NCT Number: NCT07580183

Spatial Scene Recognition Memory in Epilepsy Surgery

This study investigates the anatomical and physiological basis of spatial scene recognition memory in patients with temporal lobe epilepsy and temporal lobe lesions. Standard neuropsychological tests are insensitive to important memory deficits experienced by patients, particularly in spatial/scene memory, recollective experience, and familiarity processing. Using a validated virtual tour paradigm, the study examines how familiarity-based recognition and recall of spatial scenes relate to specific brain structures. In Aim I, a large cohort of patients with varied temporal lobe lesions at Emory University undergoes the virtual tour task with voxel-based lesion-symptom mapping to localize necessary brain regions. In Aim II, scalp event-related potentials and eye tracking in healthy participants at UC Davis characterize the temporal dynamics and lateralization of scene recognition. In Aim III, intracranial EEG recordings (including local field potentials and single-unit activity) in epilepsy surgery patients at UC Davis determine the precise network dynamics underlying spatial scene familiarity and recall. The long-term goal is to improve the prediction and prevention of cognitive morbidity from epilepsy surgery by providing a more complete model of spatial recognition memory circuits.

Recruiting

Interested in participating?

Request Info

Key information

Conditions

Focal Epilepsy Behavior Brain Diseases Central Nervous System Diseases Drug Resistant Epilepsy Epilepsies, Partial Epilepsy Epilepsy Comorbidities Epilepsy Intractable Epilepsy Surgery Epilepsy, Temporal Lobe Epileptic Syndromes Medically Refractory Epilepsy Memory Deficits Memory Disorder, Spatial Memory Disorders Memory Dysfunction Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations Orientation, Spatial Pathological Conditions, Signs and Symptoms Signs and Symptoms Spatial Behavior Spatial Perception Temporal Lobe Epilepsy

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

UC Davis Medical Center, Sacramento, California, United States

Loading trial locations.

About this study

Recognition memory can be divided into familiarity (a sense that something has been encountered before) and recollection (identification or elaborative recall). Patients with temporal lobe epilepsy often report subjective memory difficulties that are not captured by conventional neuropsychological tests, which lack assessments of true episodic and scene memory. This study uses a virtual tour paradigm that objectively separates familiarity-based recognition from recall for spatial scenes. The central hypothesis is that spatial scene recognition memory critically involves the convergence of dorsal and ventral visual streams in the inferior parietal lobule and parahippocampal gyrus, with familiarity-based recognition involving neocortical structures and recall involving the parahippocampal gyrus, entorhinal cortices, and hippocampus. The study employs three complementary approaches: (1) lesion-symptom mapping in ~310 surgical patients and 150 controls, (2) scalp ERP and eye-tracking in 80 healthy participants, and (3) intracranial electrophysiology (LFP and single-unit recordings) in ~80 patients undergoing stereoelectroencephalography (SEEG) for clinical seizure localization. Research electrodes (FDA-approved Dixi micro-macro or Behnke-Fried with tetrode components) are placed at clinically determined locations to additionally capture single-neuron activity. This study was classified as a Basic Experimental Studies in Humans (BESH) mechanism; it does not evaluate a health-related clinical outcome but uses clinical populations and FDA-approved research electrodes to study basic neuroscience questions about memory.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 years or older
  • For Aims I and III: Diagnosis of focal epilepsy or temporal lobe lesion; patients undergoing evaluation for or having undergone epilepsy surgery
  • For Aim II: Healthy adult participants
  • Full-Scale IQ ≥ 70
  • English proficiency sufficient to understand and complete the task
  • For Aim I: Enrolled in or eligible for Emory University epilepsy surgery research registry
  • For Aim III: Undergoing clinically indicated stereoelectroencephalography (SEEG) at UC Davis Medical Center
  • Able to provide informed consent (or for Aim I retrospective component, prior consent in Emory registry)

Exclusion criteria

  • Full-Scale IQ < 70
  • Inability to provide informed consent
  • For Aim III: Age > 55 years
  • For Aim II: History of neurological or psychiatric disorder (as applicable per study protocol)

Treatment and study plan

Virtual Tour Recognition Memory Task

Behavioral

Participants are passively navigated through virtual tour scenes (5-second video clips) during a study phase and are asked to generate descriptive names for each scene. During the test phase, they view novel, spatially similar (same configuration, different objects), or identical scenes and rate familiarity, indicate old/new judgments, report déjà vu sensations, and attempt to recall scene names. The task consists of two study-test blocks. This is a cognitive/behavioral assessment, not a therapeutic intervention.

Intracranial EEG Recording with Research Electrodes (Aim III only)

Device

Patients undergoing clinically indicated stereoelectroencephalography (SEEG) for seizure localization have electrodes implanted at locations determined solely by clinical need. In a subset of patients, FDA-approved research electrodes (Dixi micro-macro electrodes or Behnke-Fried As-Tech electrodes with tetrode components) substitute standard clinical electrodes at the same clinically determined locations. These electrodes have the same geometry as clinical electrodes and are FDA-approved. The tetrode component enables single-neuron recording for research purposes and adds no additional risk. Electrode placement is not altered by study participation. Local field potentials (LFP) and, where available, single-unit data are recorded during the virtual tour task and resting state.

MRI Neuroimaging and Neuropsychological Assessment (Aim I)

Diagnostic Test

Pre- and post-surgical structural MRI (T1-weighted, diffusion-weighted imaging, resting-state fMRI) obtained as part of the clinical epilepsy surgery evaluation at Emory University. Extensive neuropsychological battery administered pre- and post-operatively (6 months and 1 year) including Wechsler memory scales, Rey-Osterrieth Complex Figure, confrontation naming, and additional measures.

Primary outcomes

  1. Scene familiarity discrimination accuracy

    Time frame: From enrollment until the end of eight weeks, during which time testing is scheduled (Aim II), or during the hospitalization for invasive EEG studies (Aim III). Participants in Aim I can undergo repeat testing (six months, one year, etc.)

    Rate of correct familiarity judgments for spatially similar test scenes versus novel scenes (recognition without identification/RWI effect), measured as the proportion of "familiar" responses to configurally matched scenes minus false alarm rate to novel scenes.

  2. Scene recall accuracy

    Time frame: From enrollment until the end of eight weeks, during which time testing is scheduled (Aim II), or during the hospitalization for invasive EEG studies (Aim III). Participants in Aim I can undergo repeat testing (six months, one year, etc.)

    Proportion of test scenes for which participants correctly recall the name or identifying details of the corresponding study scene (verified recall), separately for identical repeat scenes and configurally similar scenes.

  3. Lesion-symptom correlation for familiarity and recall (Aim I)

    Time frame: Testing is scheduled within eight weeks of enrollment for all patients, with repeat testing at six and 12 months after surgery for those enrolled pre-operatively

    Voxel-based lesion-symptom mapping (VBLSM) correlating surgical lesion volumes in temporal lobe subregions (temporopolar, perirhinal, entorhinal, parahippocampal, hippocampal) with familiarity and recall behavioral scores.

  4. ERP amplitude and latency associated with familiarity and recall (Aim II)

    Time frame: During EEG recording session

    Amplitude and latency of event-related potential components (FN400, late positive component) in specified scalp regions (e.g., LAS, RAS, LPS, RPS) as a function of scene familiarity and recall conditions.

  5. Intracranial theta and gamma power and connectivity during familiarity judgments (Aim III)

    Time frame: During intracranial EEG monitoring (typically 1-2 weeks hospital stay)

    Theta (3-7 Hz) and gamma-band (30-150 Hz) event-related synchronization/desynchronization in parahippocampal, perirhinal, entorhinal, and hippocampal contacts during familiarity versus recall conditions, plus functional connectivity measures (imaginary coherence, phase-amplitude coupling).

Secondary outcomes

  1. Déjà vu report rate

    Time frame: During testing sessions with the virtual tour

    Proportion of test trials in which participants report a feeling of déjà vu, analyzed by scene condition (similar, repeat, novel).

  2. Vividness of Visual Imagery Questionnaire, Second Edition (VVIQ-2) scores (Aim I)

    Time frame: During testing session

    Self-reported vividness of visual imagery correlated with lesion location and recognition memory performance. The VVIQ-2 is a 32-item self-report questionnaire in which each item is rated on a scale from 1 (no image at all) to 5 (perfectly clear and vivid). Total scores range from 32 to 160. Higher scores indicate more vivid visual imagery.

  3. Hyperfamiliarity commission errors

    Time frame: During testing session

    Rate of false positive familiarity judgments for novel scenes (false alarms), as a measure of hyperfamiliarity.

  4. Neuropsychological test performance (Aim I)

    Time frame: Pre-surgery and 6 months / 1 year post-surgery

    Standard neuropsychological battery scores (Wechsler Memory Scale, Rey-Osterrieth Complex Figure, confrontation naming, etc.) correlated with virtual tour performance and lesion characteristics.

  5. Single-unit firing rate (subset of patients in Aim III)

    Time frame: During intracranial EEG monitoring

    Mean firing rate (spikes per second) of individual neurons recorded from parahippocampal and perirhinal cortex during familiarity versus recall conditions, in patients with tetrode/microelectrode recordings.

  6. Single-unit stimulus selectivity (subset of patients in Aim III)

    Time frame: During intracranial EEG monitoring

    Selectivity index (area under the receiver operating characteristic curve) quantifying the discriminability of familiar versus novel scene conditions in individual neurons recorded from parahippocampal and perirhinal cortex, in patients with tetrode/microelectrode recordings.

Study contacts

Contact information is provided by the study sponsor or research team.

Nigel P Pedersen, MD

CONTACT

[email protected]

916-734-3251

Sponsors and collaborators

Lead sponsor

University of California, Davis

Other

Collaborators

  • Emory University

Registry information

Official study title

Investigations of Spatial Recognition Memory to Improve Cognitive Outcomes in Epilepsy Surgery

Important dates

Study start
2024
Primary completion
2030
Study completion
2030
First posted
May 12, 2026
Registry last updated
May 12, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.