Cognitive Control Functions of the Human Thalamus
Network Mechanisms of Cognitive Control
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
There are 3 types of testing procedures, (cognitive behavioral testing, EEG, and MRI,) that investigators will describe in detail below. The types of procedures involved vary from participant to participant, depending on what kind of data investigators need and which procedure subjects agree to participate. The subject may participate in all testing procedures, (MRI, EEG, and behavioral,) two or three. The subject is also free to decline any of the testing procedures, equivalent to not participating in the research study. For each procedure, the testing time will never exceed 3 hours, so the maximum time commitment for the subject will be 9 hrs. For each subject, no more than two testing procedures will occur within 24 hours. When two testing procedures occur within the same 24-hour period, the time between the two testing procedures will be whatever is most convenient for the subject. The time between testing procedures that do not occur within the same 24-hour period will be whatever is most convenient for the subject, (this could mean weeks or months depending on the subject.) The specific procedure(s) the subject agrees to participate in will be checked on the consent form. The order which a subject will participate in these three types of procedures will also vary from subject to subject, which depends on the subject's schedule and the availability of the research facilities.
COGNITIVE BEHAVIORAL PROCEDURES: The type of cognitive task that will be administered aimed at measuring subject's ability to monitor internal goals and intentions, maintain and manipulate information in working memory, select task-relevant information, inhibit distractions, and organize action plans to accomplish these goals. These tasks involve the presentation of visual or auditory stimuli through a computer system, and the subjects must pay attention to the presented stimuli and make button press responses. Their eye movements may be monitored by a non-invasive eye-tracking device placed 1 to 2 feet in front of the participants. The eye-tracking device passively records the subject's eye gaze direction and no part of the device will be touching the subject, therefore, there will be no negative impact on the subject's comfort. The testing time for this procedure will be 1 to 3hrs.
EEG PROCEDURES: In this procedure, subjects will have EEG recorded while concurrently monitoring behavior. Subjects are asked to sit in a testing room and have conventional EEG electrodes placed on their scalp with conducting paste. The experiments involve the presentation of images on a computer monitor, sounds through speakers or headphones. The tasks may be changed flexibly as required by our behavioral testing of the tasks (i.e., is this task too easy for subjects? Too hard? These are questions investigators can only answer once investigators begin piloting the task behaviorally), however the task will always be asking subjects to manipulate the simple or complex stimuli in mind and respond to the participants in a brief period of time. The task will get at our questions about cognitive control by engaging brain regions involved in memorizing stimuli, attending to stimuli, ignoring stimuli, and preparing responses. These are components of cognitive control that are of interest for this project. The subject is asked to respond to certain stimuli by pressing a button. All stimuli are presented at a comfortable level. Similar to the cognitive behavioral procedure, a non-invasive eye tracking device may record subject's eye movements during EEG recording. This eye-tracking device is non-invasive and no parts of the device will cause any discomfort or interfere with the EEG recording. An EEG recording session typically takes 1 to 3hrs. The subject is given breaks every 5- 10 minutes, but may request a break or stop the experiment at any time. After the testing, investigators will remove the electrodes, and provide shampoo and towels for subjects to wash off the EEG conducting paste. Investigators will provide a hairdryer.
MRI (3T) PROCEDURES: Before participants enter the magnet room, participants will be screened for contradictions (i.e., metal implant). If the subject also wears glasses that contain metal to correct their visual acuity to 20/40 or better, investigators will have the subject use plastic, MR-compatible glasses provided by the MRI center. If the subject knows their prescription it will expedite the process of finding lenses suitable for the participants. If not, a few minutes will be allocated to trying on the best fitting pair to approximate the vision required to view the screen within the MRI, which is positioned close to subjects' face. Brain anatomical MRI scans are collected. Brain anatomical MRI scans are collected to determine the location of brain structures. In MRI studies, subjects who have history of brain MRIs will be acclimated to the MRI environment in a mock scanner. This is performed at a dedicated setup at MRRF in PBDB. For comfort, foam pads are placed around the subject's head to limit head movement during the scan. A MRI scanning session takes about 40 - 60 minutes and the subject is given breaks every 5-10 minutes. The subject may request a break or stop the experiment at any time.
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
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Iowa
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Iowa City, Iowa, United States, 52246
- The University of Iowa
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Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Adult
- Older Adult
Accepts Healthy Volunteers
Description
Inclusion Criteria:
- Healthy adults age 18-35 without neurological or psychological disorders. No metal implants. No Claustrophobia.
- Patients with focal lesions within the thalamus. Age 18 or older. No diagnosis of psychiatric disorders. No metal implants. No Claustrophobia.
- Patients with focal lesions that spare the frontal and parietal cortices. Age 18 or older. No diagnosis of psychiatric disorders.
No metal implants. No Claustrophobia.
Exclusion Criteria:
- claustrophobic Psychiatric conditions such as depression and ADHD. Implanted device such as cardia pacemakers and autodefbrillaotors, aneurysm, cochlear implants.
- Not fluent in English.
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)
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
|---|---|
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Experimental: Determine how the thalamus contributes to cognitive control
We conducted cognitive behavioral testing on cognitive flexibility using EEG, fMRI and behavioral experiments.
The intervention for all three methods (EEG, fMRI, behavioral) were the same, subjects performed a cognitive flexibility task with three conditions: extradimensional shift, intradimensional shift, and no switching condition.
With all three experiments we can measure the behavioral accuracy.
With fMRI we can measure evoked fMRI response amplitude in the thalamus, with EEG we can measure scalp voltage signal in patients.
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A behavioral task that requires subjects to switch between stimulus- response contingencies based on a colored contextual cue.
In addition, this task requires subjects to memorize a set of visual stimuli.
Subjects will then be presented with a test set and will be asked to indicate whether any stimulus therein is not part of original memorized set.
Three conditions will be measured, including EDS (extradimensional shift), IDS (intradimensionaly shift), and Stay (no switching).
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What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Cognitive Flexibility Performance as Measured by Accuracy, in the Unit of Percentage of Correct Responses
Time Frame: 2 weeks
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The accuracy measure of the behavioral task will determine whether the hypothesized cognitive function of cognitive flexibility is implemented by a hierarchical cognitive control model instantiated in the human thalamus.
A lower accuracy scale for the extradimensional shift condition (EDS) relative to other conditions would suggest increased difficulty in engaging in cognitive flexibility.
The scale is from 0 to 100.
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2 weeks
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Measure of Thalamus Response to Cognitive Flexibility, in the Unit of fMRI BOLD Signal Increase Relative to no Stimulus Presentation.
Time Frame: 2 hours
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When subjects perform the cognitive flexibility task, we can then measure how strongly the medial thalamus responds to different task conditions.
The signal scale will be in beta coefficients measured by fMRI BOLD response.
This is a measurement of relative signal increase in response to the presented task.
A higher beta value for the thalamus for the extradimensional shift condition would indicate thalamus involvement in cognitive flexibility.
The scale is from -100 to 100
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2 hours
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Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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EEG Oscillations in the Theta Frequency Band, in the Unit of Signal Increase Relative to Recordings From no Stimulus Presentation.
Time Frame: 2hrs
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In stroke patients, we can measure their EEG response in the theta frequency band in response to the three cognitive flexibility conditions (EDS, IDS, Stay).
The measure is percent signal change (%) from -100 to 100.
We expect that there should be no difference in this measure, indicating that the brain structure is limiting patients' ability to engage in cognitive flexibility-related brain processes.
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2hrs
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Collaborators and Investigators
Sponsor
Collaborators
Publications and helpful links
General Publications
- Shine JM, Lewis LD, Garrett DD, Hwang K. The impact of the human thalamus on brain-wide information processing. Nat Rev Neurosci. 2023 Jul;24(7):416-430. doi: 10.1038/s41583-023-00701-0. Epub 2023 May 26.
- Cellier D, Petersen IT, Hwang K. Dynamics of Hierarchical Task Representations. J Neurosci. 2022 Sep 21;42(38):7276-7284. doi: 10.1523/JNEUROSCI.0233-22.2022.
- Hwang K, Bruss J, Tranel D, Boes AD. Network Localization of Executive Function Deficits in Patients with Focal Thalamic Lesions. J Cogn Neurosci. 2020 Dec;32(12):2303-2319. doi: 10.1162/jocn_a_01628. Epub 2020 Sep 9.
- Hwang K, Shine JM, Bruss J, Tranel D, Boes A. Neuropsychological evidence of multi-domain network hubs in the human thalamus. Elife. 2021 Oct 8;10:e69480. doi: 10.7554/eLife.69480.
- Chen X, Leach SC, Hollis J, Cellier D, Hwang K. The thalamus encodes and updates context representations during hierarchical cognitive control. PLoS Biol. 2024 Dec 2;22(12):e3002937. doi: 10.1371/journal.pbio.3002937. eCollection 2024 Dec.
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- 201808855
- R01MH122613 (U.S. NIH Grant/Contract)
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
IPD Plan Description
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
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