Neurocognitive Basis of Attention and Eye Movement Guidance in the Real World Scenes

The objective of this study is to determine the effects of electrical brain stimulation (EBS) on visual search in natural scenes in humans.

Study Overview

• Status: Withdrawn
• Conditions: Cognition; Attention; Eye Movements
• Intervention / Treatment: Device: Electrical Brain Stimulation; Device: Sham Electrical Brain Stimulation

Detailed Description

The ability to conduct a visual search for an object in a naturalistic scene is a crucial component of everyday interactions with the environment. This process requires the recognition of different items, accessing stored semantic knowledge about those items and their relationships with other objects, and guiding vision based on that knowledge. Classical models of attention emphasize low-level visual salience maps for attentional guidance. However, behavioral studies increasingly support a role for object knowledge in guiding attention and eye movements. Despite strong behavioral evidence that conceptual information about objects and scenes is critical for real world guidance of attention, very little is known about the neural basis of the guidance of attention based on meaning.

Previous human imaging studies have identified several brain regions that represent object and scene/context knowledge as it relates to visual recognition. In particular, regions of the temporal lobes (inferior temporal regions (ITC), parahippocampal cortex (PHC), and the hippocampus) are critical for perceiving and understanding objects, but little is known about the role of these individual regions in how they interact to guide attention and eye movements in real-world scenes.

Electrical brain stimulation is routinely performed clinically in the surgical treatment of epilepsy patients, both intraoperatively and using implanted electrodes. It is used as standard of care both to map eloquent brain function prior to surgical treatment for epilepsy and to map the seizure network. The purpose of this study is to gain a better understanding of the information flow and neural dynamics of the brain, examining the impact of electrical brain stimulation on stimulus search time, accuracy, and eye movement trajectories.

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15213
      • UPMC Presbyterian

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Have intracranial EEG electrodes implanted for stage II epilepsy planning.
• Have adequate cognitive and communication ability to give informed consent, understand instructions, and follow direction.
• Be able to understand the tasks and provide responses.
• IQ > 75 (done as part of standard-of-care neuropsychological testing as part of the surgical treatment for epilepsy)
• Speak English

Exclusion Criteria:

• Inability to understand or perform the tasks outlined in this protocol
• In excessive postoperative discomfort.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Electrical and Sham Electrical Brain Stimulation; Electrical brain stimulation and sham electrical brain stimulation will be administered to all participants.

Device: Electrical Brain Stimulation; Electrical Brain Stimulation (EBS) will be used to disrupt local neural activity in inferior temporal regions (ITC), parahippocampal cortex (PHC), the hippocampus, and control regions. The effects of EBS will be examined on attention and eye movement behavior, and all participants will receive both EBS and sham electrical brain stimulation.; Device: Sham Electrical Brain Stimulation; Sham electrical brain stimulation (SEBS) will be applied to inferior temporal regions (ITC), parahippocampal cortex (PHC), the hippocampus, and control regions. The effects of SEBS will be examined on attention and eye movement behavior, and all participants will receive both SEBS and EBS.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of eye fixations during electrical brain stimulation (EBS) vs. sham electrical brain stimulation (SEBS).	Eye fixations will be assessed using an eye tracking device, which collects videos of eye movements. Participants will be presented with an image of a scene, and asked to locate a target object. The incidence of eye fixations occurring before participants locate the target object will be measured at preferred and control brain regions during EBS and SEBS.	Eye fixation incidence will be assessed during the intervention, through study completion, up to 1 week on average.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Search time for target object during EBS vs. SEBS.	Visual search time will be assessed by asking participants to answer a simple question about a target object in an image of a scene as quickly and accurately as possible. The question will presented to the participants, followed by the image of the scene. The search time to locate the target object and respond to the question will be measured at preferred and control brain regions during EBS and SEBS.	Search Time will be assessed during the intervention, through study completion, up to 1 week on average.
Identification accuracy during EBS vs. SEBS.	Identification accuracy rate will be assessed based on the participants' correct responses for identifying a target object in an image of a scene (described in Outcomes 1 and 2). The search time to locate the target object will be measured at preferred and control brain regions during EBS and SEBS.	Identification accuracy will be assessed during the intervention, through study completion, up to 1 week on average.

Collaborators and Investigators

• Sponsor: Avniel Ghuman
• Collaborators: National Eye Institute (NEI)
• Investigators: Principal Investigator: Avniel S Ghuman, PhD, University of Pittsburgh

Study record dates

Study Major Dates

• Study Start (Anticipated): May 1, 2022
• Primary Completion (Anticipated): June 1, 2022
• Study Completion (Anticipated): June 1, 2022

Study Registration Dates

• First Submitted: November 4, 2020
• First Submitted That Met QC Criteria: December 2, 2020
• First Posted (Actual): December 3, 2020

Study Record Updates

• Last Update Posted (Actual): June 13, 2022
• Last Update Submitted That Met QC Criteria: June 8, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Keywords: Visual Attention; Intracranial Electroencephalography; Naturalistic Vision; Electrical Brain Stimulation
• Other Study ID Numbers: STUDY19090010; 1R21EY030297-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No