Attention - no Condition is Being Assessed - Healthy AdultsPhase 4LCNCT06041048
Investigation of Locus Coeruleus Function in Sustained Attention
A Phase 4 study testing Modafinil in people with Attention - no Condition is Being Assessed - Healthy Adults, run by University of California, Davis at 1 site in United States.
Trial summary
The norepinephrine-producing locus coeruleus (LC) is thought to be central to a wide array of cognitive functions, like attention and goal pursuit, and has been implicated in dysfunctions including attention deficit hyperactivity disorder and schizophrenia. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Attention - no Condition is Being Assessed - Healthy Adults
- What is being tested?
- Modafinil
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Oct 2023to 19 Dec 2026
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Between the ages of 18 - 60 years of age,
- Typically developing, healthy adult
Who cannot join
- History of schizophrenia, other forms of psychosis,
- Specific or focal neurological disorder or severe alcohol or drug use disorder within the past 5 years
- History of left ventricular hypertrophy or in patients with mitral valve prolapse who have experienced the mitral valve prolapse syndrome when previously receiving CNS stimulants, or who have had recent history of myocardial infarction or unstable angina.
- Volunteers with known hypersensitivity to modafinil or armodafinil or its inactive ingredients
- Known allergy/sensitivity or any hypersensitivity to components of modafinil or its formulation
- Inability to swallow tablets or tolerate oral medication;
Show all 10Show fewer
- Pregnant or nursing (participants will be required to have a negative pregnancy test)
- Contraindication for MRI scanning (metal implants, pacemakers, metal foreign bodies, or pregnancy)
- Use of psychotropic medication within the past week
- Claustrophobic and not comfortable being in a small space may also not want to participate
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of California, Davis
Sacramento, California, 95817
Jared Borden, jborden@ucdavis.edu
About this study
The norepinephrine-producing locus coeruleus (LC) is thought to be central to a wide array of cognitive functions, like attention and goal pursuit, and has been implicated in dysfunctions including attention deficit hyperactivity disorder and schizophrenia. The goal of this proposal is to develop methods that permit measurement of activity in the human LC. Because the LC is small and located in the pons, the Investigators will use high resolution magnetic resonance imaging techniques tailored to the brainstem environment, including neuromelanin-sensitive images shown to delineate the LC, combined with pharmacological manipulation to confirm the location of functional activity.
Read the detailed description
Attention failures negatively impact goal pursuit and have significant consequences on performance in many environments. Attentional control of perceptual, motor and cognitive functions are believed to be partly determined by functioning of the locus coeruleus-norepinephrine (LC-NE) system. The LC, a small brainstem nucleus that is the primary source for NE in the forebrain, has motivated hypotheses about human cognition, including mental health disorders with known alterations in attention and cognition (e.g., attentiondeficit/ hyperactivity disorder (ADHD), schizophrenia) even though methods for measuring human LC activity have significant limitations. Existing methods to study LC function in humans rely on pupillometry and fMRI.
Because pupil diameter correlates with LC activity, it has been used as a proxy for LC activity. However, the anatomical pathway linking the LC to pupil dilation has not been established and pupil diameter also correlates with activity in other brain areas. Thus, inferring LC activity from pupillometry alone is problematic. fMRI has also been used to measure activity from the LC, but the imaging methods used to date have relied on resolutions that are coarse relative to the size and shape of LC. Prior fMRI results have therefore not been adequate for event-related analyses. The goal of the proposed work is to develop and validate methods for using fMRI to measure LC activity, specifically event-related responses that will allow for testing of influential hypotheses of LC function in humans. This goal is appropriate for the R21 mechanism, which is meant to "encourage exploratory/developmental research by providing support for the early and conceptual stages of project development" and to test innovative, high-risk, high reward research. This project has two specific aims, which are both tested with sustained attention tasks. The first aim uses high-resolution fMRI to maximize the number of measurements within LC combined with neuromelanin-sensitive imaging to localize BOLD responses to LC. The Investigators will measure (a) pre-trial activity (i.e., during inter-trial intervals; this period is thought to reflect tonic LC activity) and (b) trial response (i.e., phasic LC activity) by estimating the beta weights for each trial. The second aim uses modafinil administration to modulate LC activity and confirm the location of BOLD responses measured during the sustained attention tasks to the LC. The Investigators will administer modafinil and placebo to participants in a double-blind, placebo-controlled crossover study. Pupillometry data will also be collected for both the modafinil and placebo conditions, and the Investigators will use the pupillometry data to test for a correlation with LC BOLD response amplitude. This combination of techniques will demonstrate whether fMRI can be used to measure LC activity in a targeted fashion. Developing these tools meets Goal 1 (Strategy 1.3D) of the 2020 Strategic Plan of the NIMH by permitting direct measurement of a brain structure central in attentional control.
- Being tested
- Modafinil
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ModafinilDrug
Also called Provigil
Single dose (200 mg) of medication versus placebo given to healthy control subjects
| Study group | Role | What they receive |
|---|---|---|
| Modafinil | Active comparator | Single oral dose (200 mg) of medication versus placebo given to healthy control subjects Receives: Drug: Modafinil |
| Placebo | Placebo comparator | Oral placebo Receives: Drug: Modafinil |
What is being measured
The primary outcome is the main question the study is designed to answer.
Brain activity - BOLD response
Measured: 1 hour
Secondary outcomes (1)
Attention on Oddball and POP task
Response time and accuracy on Oddball and POP task
Measured: 1 hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Sep 2023
- Study start1 Oct 2023
- Primary completion19 Dec 2026 (estimated)
- Study completion19 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Attention - no Condition is Being Assessed - Healthy AdultsStudies of the same condition, open and under way.
- More trials run by University of California, DavisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Davis
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06041048
- Sponsor's protocol ID
- 1939774
- Acronym
- LC
- Status last verified
- Jun 2026
- First submitted
- 17 Jul 2023
- Last updated
- 18 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified data will be uploaded to the NIH NDA, following their procedures.
Study at a glance
From the registry record, last updated by the sponsor on 18 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of Locus Coeruleus Function in Sustained Attention
- ClinicalTrials.gov ID
- NCT06041048
- Acronym / sponsor ID
- LC / 1939774
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of California, DavisUniversity, hospital or other
- Study start
- 1 Oct 2023 (actual)
- Primary completion
- 19 Dec 2026 (estimated)
- Study completion
- 19 Dec 2026 (estimated)
- First posted
- 18 Sep 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The norepinephrine-producing locus coeruleus (LC) is thought to be central to a wide array of cognitive functions, like attention and goal pursuit, and has been implicated in dysfunctions including attention deficit hyperactivity disorder and schizophrenia. The goal of this proposal is to develop methods that permit measurement of activity in the human LC. Because the LC is small and located in the pons, the Investigators will use high resolution magnetic resonance imaging techniques tailored to the brainstem environment, including neuromelanin-sensitive images shown to delineate the LC, combined with pharmacological manipulation to confirm the location of functional activity.
Detailed description
Attention failures negatively impact goal pursuit and have significant consequences on performance in many environments. Attentional control of perceptual, motor and cognitive functions are believed to be partly determined by functioning of the locus coeruleus-norepinephrine (LC-NE) system. The LC, a small brainstem nucleus that is the primary source for NE in the forebrain, has motivated hypotheses about human cognition, including mental health disorders with known alterations in attention and cognition (e.g., attentiondeficit/ hyperactivity disorder (ADHD), schizophrenia) even though methods for measuring human LC activity have significant limitations. Existing methods to study LC function in humans rely on pupillometry and fMRI.
Because pupil diameter correlates with LC activity, it has been used as a proxy for LC activity. However, the anatomical pathway linking the LC to pupil dilation has not been established and pupil diameter also correlates with activity in other brain areas. Thus, inferring LC activity from pupillometry alone is problematic. fMRI has also been used to measure activity from the LC, but the imaging methods used to date have relied on resolutions that are coarse relative to the size and shape of LC. Prior fMRI results have therefore not been adequate for event-related analyses. The goal of the proposed work is to develop and validate methods for using fMRI to measure LC activity, specifically event-related responses that will allow for testing of influential hypotheses of LC function in humans. This goal is appropriate for the R21 mechanism, which is meant to "encourage exploratory/developmental research by providing support for the early and conceptual stages of project development" and to test innovative, high-risk, high reward research. This project has two specific aims, which are both tested with sustained attention tasks. The first aim uses high-resolution fMRI to maximize the number of measurements within LC combined with neuromelanin-sensitive imaging to localize BOLD responses to LC. The Investigators will measure (a) pre-trial activity (i.e., during inter-trial intervals; this period is thought to reflect tonic LC activity) and (b) trial response (i.e., phasic LC activity) by estimating the beta weights for each trial. The second aim uses modafinil administration to modulate LC activity and confirm the location of BOLD responses measured during the sustained attention tasks to the LC. The Investigators will administer modafinil and placebo to participants in a double-blind, placebo-controlled crossover study. Pupillometry data will also be collected for both the modafinil and placebo conditions, and the Investigators will use the pupillometry data to test for a correlation with LC BOLD response amplitude. This combination of techniques will demonstrate whether fMRI can be used to measure LC activity in a targeted fashion. Developing these tools meets Goal 1 (Strategy 1.3D) of the 2020 Strategic Plan of the NIMH by permitting direct measurement of a brain structure central in attentional control.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Modafinil | Active comparator | Drug: ModafinilSingle oral dose (200 mg) of medication versus placebo given to healthy control subjects |
| Placebo | Placebo comparator | Drug: ModafinilOral placebo |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Between the ages of 18 - 60 years of age,
- Typically developing, healthy adult
Key exclusion criteria (10 listed)
- History of schizophrenia, other forms of psychosis,
- Specific or focal neurological disorder or severe alcohol or drug use disorder within the past 5 years
- History of left ventricular hypertrophy or in patients with mitral valve prolapse who have experienced the mitral valve prolapse syndrome when previously receiving CNS stimulants, or who have had recent history of myocardial infarction or unstable angina.
- Volunteers with known hypersensitivity to modafinil or armodafinil or its inactive ingredients
- Known allergy/sensitivity or any hypersensitivity to components of modafinil or its formulation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ModafinilAlso: ProvigilSingle dose (200 mg) of medication versus placebo given to healthy control subjects | Drug | Modafinil, Placebo |
Primary outcome
Brain activity - BOLD response
Time frame: 1 hour
1 secondary outcome
Attention on Oddball and POP task
Time frame: 1 hour
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Jun 2026.
- Individual participant dataSharing planned: Yes. De-identified data will be uploaded to the NIH NDA, following their procedures.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Modafinil in people with Attention - no Condition is Being Assessed - Healthy Adults, run by University of California, Davis at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Julie Schweitzer, PhD (9167030450, jschweitzer@ucdavis.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Brain activity - BOLD response (time frame: 1 hour). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jun 2026.