Spatial Scene Recognition Memory in Epilepsy Surgery

Purpose

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.

Conditions

  • Focal Epilepsy
  • Temporal Lobe Epilepsy
  • Medically Refractory Epilepsy
  • Memory Disorders
  • Epilepsy Comorbidities
  • Epilepsy Intractable
  • Epilepsy Surgery
  • Epilepsy, Temporal Lobe
  • Memory Deficits
  • Memory Disorder, Spatial
  • Memory Dysfunction
  • Spatial Perception

Eligibility

Eligible Ages
Between 18 Years and 55 Years
Eligible Sex
All
Accepts Healthy Volunteers
Yes

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)

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Parallel Assignment
Intervention Model Description
Note: Under the NIH clinical trial definition used at the time of submission (2024-2025), this study is classified as a clinical trial because participants are prospectively assigned to interventions (cognitive testing paradigms; in Aim III, research electrode recordings). However, the primary purpose is basic science - understanding the neural basis of memory - not evaluating a clinical/health outcome.
Primary Purpose
Basic Science
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Aim I: Lesion-Symptom Mapping 		Patients with temporal lobe lesions (n≈310) and healthy controls (n≈150) at Emory University. Retrospective cohort with existing surgical lesions plus prospectively enrolled new surgical patients (~60 over 5 years). Intervention(s): Behavioral: Virtual Tour Recognition Memory Task; Diagnostic: MRI neuroimaging and neuropsychological assessment
  • Behavioral: Virtual Tour Recognition Memory Task
    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.
  • Diagnostic Test: MRI Neuroimaging and Neuropsychological Assessment (Aim I)
    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.
Experimental
Aim II: Scalp ERP Study 		Healthy participants (n=80) recruited from UC Davis campus community. Intervention: Behavioral: Virtual Tour Recognition Memory Task (still-image version) during Scalp EEG/ERP recording and eye tracking
  • Behavioral: Virtual Tour Recognition Memory Task
    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.
Experimental
Aim III: Intracranial EEG 		Patients with epilepsy undergoing clinically indicated SEEG (n≈80) at UC Davis Medical Center. Behavioral Intervention: Virtual Tour Recognition Memory Task; Other Intervention: Intracranial EEG recording via clinically placed electrodes, a minority of which have research microelectrodes (FDA-approved Dixi micro-macro or Behnke-Fried Ad-Tech electrodes)
  • Behavioral: Virtual Tour Recognition Memory Task
    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.
  • Device: Intracranial EEG Recording with Research Electrodes (Aim III only)
    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.

Recruiting Locations

UC Davis Medical Center
Sacramento, California 95817
Contact:
Nigel P Pedersen, MD
916-734-3251
nppedersen@health.ucdavis.edu

Emory University Hospital
Atlanta, Georgia 30322
Contact:
Daniel L Drane, PhD
404-727-2844
ddrane@emory.edu

More Details

Status
Recruiting
Sponsor
University of California, Davis

Study Contact

Nigel P Pedersen, MD
916-734-3251
nppedersen@health.ucdavis.edu

Detailed Description

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.