Clinical trial NCT04652856: Neurocognitive Basis of Attention and Eye Movement Guidance in the Real World Scenes
Official title: Neurocognitive Basis of Attention and Eye Movement Guidance in the Real World Scenes
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: NA
Conditions: Cognition
Attention
Eye Movements
Keywords: Visual Attention
Naturalistic Vision
Intracranial Electroencephalography
Electrical Brain Stimulation
Lead sponsor: University of Pittsburgh
Sponsor class: OTHER
Collaborators: name: National Eye Institute (NEI)
First posted: 2020-12-03
Enrollment: 0
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: All participants will undergo both electrical brain stimulation (EBS) and sham electrical brain stimulation (SEBS) at brain locations where alteration of visual attention behavior is expected to occur, as well as at control locations.

The participants will be informed that they will receive both EBS and SEBS, but blinded to the location of each trial and whether the trial is EBS or SEBS. Participants will also be blinded to the objectives of stimulation.

The order of stimulation locations and whether the trial is EBS or SEBS will be randomized.
Primary purpose: BASIC_SCIENCE

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

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Incidence of eye fixations during electrical brain stimulation (EBS) vs. sham electrical brain stimulation (SEBS).
timeFrame: Eye fixation incidence will be assessed during the intervention, through study completion, up to 1 week on average.
Secondary outcomes:
measure: Search time for target object during EBS vs. SEBS.
timeFrame: Search Time will be assessed during the intervention, through study completion, up to 1 week on average.
measure: Identification accuracy during EBS vs. SEBS.
timeFrame: Identification accuracy will be assessed during the intervention, through study completion, up to 1 week on average.
Other outcomes:
Locations:
city: Pittsburgh
country: United States
facility: UPMC Presbyterian
state: Pennsylvania
Study officials:
affiliation: University of Pittsburgh
name: Avniel S Ghuman, PhD
role: PRINCIPAL_INVESTIGATOR
References: