Investigating Mediodorsal Thalamus Representations Underlying Human Cognitive Flexibility
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-35
SponsorKai Hwang
About this trial
The goal of this basic experimental research study is to examine how the human thalamus supports flexible thinking and behavior. Specifically, the research aims to elucidate how the mediodorsal (MD) thalamus encodes and updates "context"-the mental framework that determines which rules or actions are relevant in a given situation. This work may contribute to understanding why certain psychiatric conditions, such as schizophrenia and ADHD, involve difficulties with cognitive flexibility and control.
The primary research questions are:
Does the MD thalamus represent the context that organizes how working memory guides task selection? Does the MD thalamus signal when context needs to be updated after a change in task demands? Do these thalamic representations support generalization to new situations or rules?
Participants will complete cognitive tasks while undergoing high-resolution brain imaging using 7-Tesla MRI. The investigators will combine behavioral data, computational modeling, and advanced neuroimaging analyses to examine how the thalamus interacts with the cortex during flexible decision-making.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
No history of any neurological, psychiatric, or medical condition that could affect cognition
No use of benzodiazepines, long-acting opioids, or other psychotropic drugs that could alter cognitive performance
Normal or corrected-to-normal vision (visual acuity)
Normal color perception (Farnsworth-Munsell 100 Hue Test)
Disqualifiers
Has a history of any neurological, psychiatric, or medical condition that could affect cognition
Use of benzodiazepines, long-acting opioids, or other psychotropic drugs that could alter cognitive performance
Not fluent in English
Known metal implants (including aneurysm clip, cardiac pacemaker, ICD, IUD, neurostimulation system, spinal cord stimulator, internal electrodes or wires, bone stimulator, ear implant, insulin or other infusion pump or device, prosthesis, artificial or prosthetic limb, shunt, vascular access port or catheter, thermodilution catheter, medication patch, radiation seeds or implants, wire mesh implant, tissue expander, surgical staples or clips or sutures, joint replacement, joint/bone pin/screw/nail/wire/plate, dentures, or non-removable hearing aid)
Trial design
Design model
Single group
Treatments tested in this trial
High-resolution fMRI during working memory, cognitive control, and decision-making tasks
Other interventionParticipants will perform a set of computerized cognitive tasks designed to test working memory, cognitive control, and decision-making while undergoing high-resolution 7-Tesla functional MRI. These tasks require participants to maintain and update contextual information, switch between rules, and make value-based choices under changing conditions. The intervention is distinguished by its integration of advanced neuroimaging with computational modeling to identify how the mediodorsal thalamus and prefrontal cortex represent, update, and generalize context. This approach allows precise mapping of thalamocortical mechanisms that support flexible cognition and goal-directed behavior.
Treatment groups
100 Participants
are divided into 1 treatment groupGroup A: Within subject manipulation of working memory, cognitive control, and decision makingExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Decoding of context representations in the medial dorsal thalamus from 7 T MRI data
This outcome measure will quantify the extent to which multivariate patterns of brain activity in the MD thalamus encode task context. High-resolution 7-Tesla fMRI data will be analyzed using computational modeling and multivariate pattern analysis (MVPA) techniques. The primary metric will be decoding accuracy, expressed as a percentage ranging from 0% to 100%. Decoding accuracy reflects how well task contexts for working memory, cognitive control, and decision-making can be predicted from MD thalamic activity patterns. A value of 0% indicates chance-level or poor performance, while 100% indicates perfect prediction accuracy. For each participant, decoding accuracy will be computed as a single value using the same unit of measure (percentage accuracy). This value will reflect the overall ability to decode task context from MD activity and thus serves as the primary measure of this research study.
Time frame
Measured throughout the MRI session (approximately 90 minutes per participant).Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Kai Hwang
Lead sponsor
University of Iowa
Sponsor institution
Source ClinicalTrials.gov