We are withdrawing this study due to issues with recruitment. These issues arose as a result of the COVID-19 pandemic, effecting the availability of patients and our ability as a lab to work with these patients.

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

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.

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.