ConductCognition

  • Domains

    Tests

    • Processing speed43
    • Attention113
    • Working memory50
    • Executive function143
    • Episodic memory72
    • Response inhibition9
    • Social cognition75
    • Language42

    Most used

    Evidence

    1. Verbal Fluency TestGradeA
    2. Stroop Color-Word TestGradeA
    3. Trail Making TestGradeA
    4. N-Back TaskGradeA
    5. Go/No-Go TaskGradeA
    6. Digit Span TestGradeA
    7. Symbol Coding TestGradeA
    8. Verbal Learning TestGradeA
    REDTry it nowStroop Color-Word Test
    All 547 tests

    Browse by

    • Phone290
    • Tablet323
    • Untimed326
    • Up to 5 minutes69
    • Evidence grade A40

  • First studies

    Grade, length

    • Reaction Time StudyGradeA7 min
    • Pilot ScreeningGradeA15 min
    • Medication StudiesGradeA−26 min
    • Language-Minimized ScreeningGradeA−30 min

    Age groups

    • Older Adult Executive SpeedGradeA20 min
    • School-AgeGradeA−33 min

    Memory

    • At-Home MemoryGradeA26 min
    • Working Memory and LearningGradeA−19 min
    • Associative MemoryGradeB32 min
    • Working Memory CapacityGradeB34 min

    Language and perception

    • LanguageGradeA−33 min
    • Visual PerceptionGradeB27 min
    • Listening and Auditory ProcessingGradeB31 min

    Executive function and attention

    • Executive ControlGradeA18 min
    • Attention and ImpulsivityGradeA−26 min
    • Visual AttentionGradeB27 min
    • Creativity and Flexible ThinkingGradeB30 min
    • Reasoning and SpatialGradeB32 min

    Movement

    • Motor and AttentionGradeA−29 min
    • Motor LearningGradeB34 min

    Behavior, mood and choice

    • Food Choice and Self-ControlGradeA−29 min
    • Sleep and FatigueGradeB23 min
    • Social CognitionGradeB23 min
    • Impulsivity and Substance UseGradeB26 min
    • Emotion and MoodGradeB28 min
    • Decisions and RewardGradeB29 min
    All 26 batteries

    Find one

    Up to 15 minutes2Up to 30 minutes19Phone8
    Test order labBattery gradesHow batteries work

  • Use and evidence

    • Overview
    • Compare all 547 tests
    • Test-retest
    • Reliability and validity
    • Battery grades26
    • Download and cite

    Clinical trials

    • Overview
    • By condition25
    • By test101
    • Trial design benchmark
    • Cognitive outcomes, 2026

    Conditions

    Registered studies

    • Dementia and Alzheimer's1,673
    • Aging, frailty and exercise1,398
    • Depression and bipolar disorder1,247
    • Stroke1,233
    • Substance use and addiction895
    • Parkinson's disease892
    • Cancer760
    All 25 conditions
    16,361Registered studies name a cognitive test in an outcome measure11,688 name a test you can run hereExplore the studies
  • 1

    Build

    • Study design
    • Customize tests
    • Repeat visits
    • Study cost calculator
    2

    Recruit

    • Recruitment setup
    • Prolific
    • Sona Systems
    • CloudResearch Connect
    • Qualtrics
    3

    Run

    • Remote testing
    • Participant devices
    • Phone timing check
    • Offline edition
    4

    Results

    • Automated scoring
    • Test norms
    • Study Quality Monitor
    • Data export
    Platform overview

    Compliance

    • HIPAA-ready testing
    • US clinical research
    • Data Policy
    • Privacy Policy
    • Terms of Use

  • Research areas

    Tests used in each

    • Aging and dementia188
    • Decisions and reward105
    • Child development and education87
    • Language and bilingualism64
    • Social behavior62
    • Psychiatric groups35
    • Training and intervention28
    • Mood, anxiety and trauma25
    • Substance use and impulsivity25
    • Neurological and movement research19
    • Brain injury and concussion14
    • Sleep and fatigue14
    • ADHD11
    • Eating and obesity8
    • Medication and drug trials8

    Research settings

    • Student participant pools
    • Teaching a class
    • Clinical trials
    • US clinical research
    • Sites without internet
    Planning a study?

  • Methods

    • How evidence grades work
    • How test batteries work
    • How test order works
    Methods and questions

    Help

    • FAQ
    • Recruitment guides
    • Compare platforms

    Updates

    • Blog
    • New tests by email
    Latest post10 November 2026What you can do in ConductCognition todayA short tour of ConductCognition as it stands on 10 November. After this, we'll post when something changes how you run a study.Read the post
  • Pricing
Start Free
Log In
Log InStart Free
  1. Home
  2. /Data
  3. /Clinical trials
  4. /Conditions
  5. /Parkinson's disease
  6. /Verbal Learning

Clinical trials data

Verbal Learning in Parkinson's disease trials: 61 registered studies

Every registered Parkinson's disease study on ClinicalTrials.gov that names Verbal Learning in an outcome measure: how often it is a primary outcome, the tests named with it, how large the studies are and when they measure it.

Registered Parkinson's disease studies name it in an outcome measure
61
Name it in a primary outcome, 36%
22 of 61
Of the condition's 892 studies name it, against 11% of all registered studies
7%
Other conditions
Median participants per study
45
By phase
Try Verbal LearningTry the Grocery Trip Game

Tests named in the same studies

The library tests that Parkinson's disease studies naming Verbal Learning name most often beside it.
  1. 1

    Verbal Fluency33 studies, 10 as a primary outcome

  2. 2

    Trail Making Test32 studies, 10 as a primary outcome

  3. 3

    Stroop Color-Word Test21 studies, 7 as a primary outcome

  4. 4

    Digit Span Test21 studies, 4 as a primary outcome

  5. 5

    Line Angle Matching17 studies, 5 as a primary outcome

  6. 6

    Picture Naming Test16 studies, 4 as a primary outcome

  7. 7

    Category Fluency12 studies, 5 as a primary outcome

  8. 8

    Card Sorting Test (Berg)10 studies, 5 as a primary outcome

  9. 9

    Complex Figure Copy and Recall10 studies, 2 as a primary outcome

  10. 10

    Symbol Coding7 studies, 1 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Studies by start year

Each study counted once. 2026 is partly planned starts.
02000: 0 studies, 0 with a test as a primary outcome20002001: 0 studies, 0 with a test as a primary outcome2002: 0 studies, 0 with a test as a primary outcome2003: 2 studies, 0 with a test as a primary outcome2004: 0 studies, 0 with a test as a primary outcome2005: 0 studies, 0 with a test as a primary outcome20052006: 0 studies, 0 with a test as a primary outcome2007: 1 studies, 0 with a test as a primary outcome2008: 0 studies, 0 with a test as a primary outcome2009: 0 studies, 0 with a test as a primary outcome2010: 0 studies, 0 with a test as a primary outcome20102011: 2 studies, 2 with a test as a primary outcome2012: 3 studies, 2 with a test as a primary outcome2013: 1 studies, 1 with a test as a primary outcome2014: 3 studies, 0 with a test as a primary outcome2015: 2 studies, 0 with a test as a primary outcome20152016: 2 studies, 0 with a test as a primary outcome2017: 6 studies, 2 with a test as a primary outcome2018: 4 studies, 2 with a test as a primary outcome2019: 6 studies, 3 with a test as a primary outcome2020: 3 studies, 2 with a test as a primary outcome20202021: 3 studies, 2 with a test as a primary outcome2022: 5 studies, 1 with a test as a primary outcome2023: 2 studies, 1 with a test as a primary outcome2024: 5 studies, 2 with a test as a primary outcome2025: 5 studies, 1 with a test as a primary outcome20252026: 6 studies, 1 with a test as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

Show as a table
Registered studies by start year
Start yearStudiesA test as a primary outcome
200000
200100
200200
200320
200400
200500
200600
200710
200800
200900
201000
201122
201232
201311
201430
201520
201620
201762
201842
201963
202032
202132
202251
202321
202452
202551
202661

Phases and study sizes

By phase

  • Early phase 12 studies, 0 as a primary outcome
  • Phase 12 studies, 0 as a primary outcome
  • Phase 1/21 studies, 1 as a primary outcome
  • Phase 211 studies, 1 as a primary outcome
  • Phase 31 studies, 1 as a primary outcome
  • Phase 42 studies, 1 as a primary outcome
  • Not applicable29 studies, 10 as a primary outcome
  • Observational13 studies, 8 as a primary outcome

Participants per study

102050100200
  • Phase 274 median, 36 to 114
  • Not applicable32 median, 23 to 50
  • Observational71 median, 48 to 137
Participants per study. The bar spans the middle half of the studies in each phase, the mark is the median, and the axis is logarithmic. Phases with fewer than 10 studies that give a size are left out.
Show as a table
Participants per Parkinson's disease study that names Verbal Learning, by phase
PhaseStudies with a sizeMedianMiddle half
Phase 2117436 to 114
Not applicable293223 to 50
Observational127148 to 137

When Parkinson's disease trials measure it

Half of the primary outcomes that name Verbal Learning are measured within 11 weeks of the start, and the middle half from the first day to 6 months. 20 primary outcomes give a duration.

Latest time point of each outcome

  • Within a day12 outcomes, 6 as a primary outcome
  • Up to 4 weeks10 outcomes, 3 as a primary outcome
  • 1 to 3 months10 outcomes, 2 as a primary outcome
  • 3 to 6 months14 outcomes, 5 as a primary outcome
  • 6 to 12 months4 outcomes, 3 as a primary outcome
  • 1 to 2 years3 outcomes, 0 as a primary outcome
  • Over 2 years4 outcomes, 1 as a primary outcome
  • No duration given4 outcomes, 2 as a primary outcome

A test as a primary outcomeOnly in secondary or other outcomes

57 of the 61 outcome measures give a duration. A single visit counts as within a day.

Status, results, interventions and countries

Status

  • Recruiting15 studies, 4 as a primary outcome
  • Not yet recruiting2 studies, 1 as a primary outcome
  • Active, not recruiting2 studies, 1 as a primary outcome
  • Completed26 studies, 11 as a primary outcome
  • Stopped early6 studies, 2 as a primary outcome
  • Status unknown10 studies, 3 as a primary outcome

What they test

  • Behavioral13 studies, 4 as a primary outcome
  • Drug16 studies, 4 as a primary outcome
  • Device13 studies, 5 as a primary outcome
  • Dietary supplement1 studies, 0 as a primary outcome
  • Procedure3 studies, 1 as a primary outcome
  • Diagnostic test3 studies, 3 as a primary outcome
  • Biological3 studies, 1 as a primary outcome
  • Radiation2 studies, 2 as a primary outcome
  • Genetic1 studies, 1 as a primary outcome
  • Other14 studies, 7 as a primary outcome
  • None given5 studies, 2 as a primary outcome

Intervention types as registered. A study can list several; observational studies often list none.

Where their sites are

  • United States28 studies, 12 as a primary outcome
  • Netherlands6 studies, 0 as a primary outcome
  • Sweden6 studies, 1 as a primary outcome
  • Germany4 studies, 0 as a primary outcome
  • Italy4 studies, 3 as a primary outcome
  • Switzerland4 studies, 2 as a primary outcome
  • China3 studies, 1 as a primary outcome
  • France3 studies, 0 as a primary outcome
  • Spain3 studies, 1 as a primary outcome
  • United Kingdom3 studies, 0 as a primary outcome
  • Canada2 studies, 0 as a primary outcome
  • Czechia2 studies, 0 as a primary outcome

20 countries in all. A study with sites in several counts in each; 0 list no site.

Reported results

Completed studies with results posted on ClinicalTrials.gov, a results paper the registry links to the study, or both.

Completed Parkinson's disease studies that name Verbal Learning: 16 of 26, 62%

Every completed study with a cognitive outcome: 3,626 of 7,953, 46%

Completed Parkinson's disease studies that name Verbal Learning and every completed study, by how they reported results
ResultsCompleted Parkinson's disease studies that name Verbal LearningEvery completed study
Results on ClinicalTrials.gov and a paper5, 19%776, 10%
Results on ClinicalTrials.gov only8, 31%1,139, 14%
A results paper only3, 12%1,711, 22%
Neither10, 38%4,327, 54%

The 61 studies

Filter by phase, sponsor, status, country, intervention, outcome list, size and start year. Each study links to its record on ClinicalTrials.gov.
ConditionParkinson's disease
TestVerbal Learning

61 studies match. 22 name Verbal Learning in a primary outcome. Median size 45 participants. Median time to the primary outcome: 11 weeks.

Loading 61 studies; the filters turn on when they arrive.

By start year
02462000: 0 studies, 0 naming Verbal Learning in a primary outcome20002001: 0 studies, 0 naming Verbal Learning in a primary outcome2002: 0 studies, 0 naming Verbal Learning in a primary outcome2003: 2 studies, 0 naming Verbal Learning in a primary outcome2004: 0 studies, 0 naming Verbal Learning in a primary outcome2005: 0 studies, 0 naming Verbal Learning in a primary outcome20052006: 0 studies, 0 naming Verbal Learning in a primary outcome2007: 1 studies, 0 naming Verbal Learning in a primary outcome2008: 0 studies, 0 naming Verbal Learning in a primary outcome2009: 0 studies, 0 naming Verbal Learning in a primary outcome2010: 0 studies, 0 naming Verbal Learning in a primary outcome20102011: 2 studies, 2 naming Verbal Learning in a primary outcome2012: 3 studies, 2 naming Verbal Learning in a primary outcome2013: 1 studies, 1 naming Verbal Learning in a primary outcome2014: 3 studies, 0 naming Verbal Learning in a primary outcome2015: 2 studies, 0 naming Verbal Learning in a primary outcome20152016: 2 studies, 0 naming Verbal Learning in a primary outcome2017: 6 studies, 2 naming Verbal Learning in a primary outcome2018: 4 studies, 2 naming Verbal Learning in a primary outcome2019: 6 studies, 3 naming Verbal Learning in a primary outcome2020: 3 studies, 2 naming Verbal Learning in a primary outcome20202021: 3 studies, 2 naming Verbal Learning in a primary outcome2022: 5 studies, 1 naming Verbal Learning in a primary outcome2023: 2 studies, 1 naming Verbal Learning in a primary outcome2024: 5 studies, 2 naming Verbal Learning in a primary outcome2025: 5 studies, 1 naming Verbal Learning in a primary outcome20252026: 6 studies, 1 naming Verbal Learning in a primary outcome

2026 is partly planned starts.

Show as a table
Matching studies by start year
Start yearStudiesAs a primary outcome
200000
200100
200200
200320
200400
200500
200600
200710
200800
200900
201000
201122
201232
201311
201430
201520
201620
201762
201842
201963
202032
202132
202251
202321
202452
202551
202661

Library tests named most

  • Verbal Learning61 studies, 22 as a primary outcome
  • Verbal Fluency33 studies, 10 as a primary outcome
  • Trail Making Test32 studies, 10 as a primary outcome
  • Stroop Color-Word Test21 studies, 7 as a primary outcome
  • Digit Span Test21 studies, 4 as a primary outcome
  • Line Angle Matching17 studies, 5 as a primary outcome
  • Picture Naming Test16 studies, 4 as a primary outcome
  • Category Fluency12 studies, 5 as a primary outcome
  • Card Sorting Test (Berg)10 studies, 5 as a primary outcome
  • Complex Figure Copy and Recall10 studies, 2 as a primary outcome

Largest condition groups

  • Parkinson's disease61 studies, 22 as a primary outcome
  • Mild cognitive impairment7 studies, 4 as a primary outcome
  • Dementia and Alzheimer's6 studies, 5 as a primary outcome
  • Sleep and sleep disorders6 studies, 3 as a primary outcome
  • Aging, frailty and exercise5 studies, 1 as a primary outcome
  • Depression and bipolar disorder4 studies, 1 as a primary outcome
  • Multiple sclerosis3 studies, 1 as a primary outcome
  • Epilepsy2 studies, 1 as a primary outcome
  • Stroke1 study, 1 as a primary outcome
  • Brain injury and concussion1 study, 1 as a primary outcome
  • Schizophrenia and psychosis1 study, 0 as a primary outcome
  • Cancer1 study, 1 as a primary outcome

Phases

Participants

Lead sponsor: industry 4, other 57. Interventional 48, observational 13.

As a primary outcomeSecondary or other outcomeVerbal Learning

The studies, newest registration first

Each number opens the study's record on ClinicalTrials.gov.

Registered studies that match the filters, newest registration first, with the library tests each one names and the outcome list that names them.
StudyStartPhaseConditionsParticipantsLead sponsorStatusLibrary tests named, with the latest time point
NCT07651085Start2024PhaseObservationalConditionsDementia and Alzheimer's, Mild cognitive impairment, Parkinson's disease, Sleep and sleep disordersParticipants65Lead sponsorOtherStatusActive, not recruitingLibrary tests named
  • Verbal LearningPrimary
  • Verbal FluencyPrimary
  • Category FluencyPrimary
  • Clock Drawing TaskPrimary
NCT07610369Start2026PhasePhase 2ConditionsParkinson's disease, Depression and bipolar disorderParticipants40Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal LearningSecondary13 weeks
  • Digit Span TestSecondary13 weeks
  • Delay DiscountingSecondary13 weeks
  • Probabilistic Reversal LearningSecondary13 weeks
  • Simon TaskSecondary13 weeks
NCT07540325Start2026PhaseObservationalConditionsParkinson's diseaseParticipants30Lead sponsorOtherStatusNot yet recruitingLibrary tests named
  • Stroop Color-Word TestPrimarysame day
  • Verbal LearningPrimarysame day
  • Digit Span TestPrimarysame day
  • Picture Naming TestPrimarysame day
  • Line Angle MatchingPrimarysame day
NCT07355842Start2026PhaseNot applicableConditionsParkinson's disease, Sleep and sleep disordersParticipants80Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary18 months
  • Stroop Color-Word TestSecondary18 months
  • Verbal LearningSecondary18 months
  • Verbal FluencySecondary18 months
  • Digit Span TestSecondary18 months
  • Category FluencySecondary18 months
  • Picture Naming TestSecondary18 months
  • Psychomotor Vigilance TaskOther outcome18 months
  • Complex Figure Copy and RecallSecondary18 months
  • Finger Tapping TaskSecondary18 months
  • Sustained Attention to ResponseOther outcome18 months
  • Line Angle MatchingSecondary18 months
NCT07312110Start2026PhasePhase 2ConditionsParkinson's diseaseParticipants100Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal LearningSecondary6 months
NCT07271927Start2025PhaseNot applicableConditionsParkinson's diseaseParticipants15Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary10 weeks
  • Stroop Color-Word TestSecondary10 weeks
  • Verbal LearningSecondary10 weeks
  • Digit Span TestSecondary10 weeks
  • Complex Figure Copy and RecallSecondary10 weeks
NCT07262658Start2022PhaseObservationalConditionsParkinson's diseaseParticipants40Lead sponsorOtherStatusCompletedLibrary tests named
  • Trail Making TestPrimarysame day
  • Verbal LearningPrimarysame day
  • Verbal FluencyPrimarysame day
  • Category FluencyPrimarysame day
  • Card Sorting Test (Berg)Primarysame day
  • Paced Visual Serial Addition TestPrimarysame day
  • Symbol Scan TaskPrimarysame day
NCT07214974Start2026PhaseEarly phase 1ConditionsDementia and Alzheimer's, Mild cognitive impairment, Parkinson's diseaseParticipants600Lead sponsorIndustryStatusNot yet recruitingLibrary tests named
  • Trail Making TestSecondary5 years
  • Verbal LearningSecondary5 years
  • Picture Naming TestSecondary5 years
NCT07154511Start2025PhasePhase 1/2ConditionsDementia and Alzheimer's, Parkinson's diseaseParticipants45Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestPrimary14 weeks
  • Verbal LearningPrimary14 weeks
  • Verbal FluencyPrimary14 weeks
  • Line Angle MatchingPrimary14 weeks
NCT07055087Start2026PhasePhase 2ConditionsParkinson's diseaseParticipants120Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary2 years
  • Stroop Color-Word TestSecondary2 years
  • Verbal LearningSecondary2 years
  • Verbal FluencySecondary2 years
  • Category FluencySecondary2 years
  • Picture Naming TestSecondary2 years
  • Short Story RecallSecondary2 years
  • Line Angle MatchingSecondary2 years
NCT06906276Start2025PhaseObservationalConditionsParkinson's disease, Aging, frailty and exerciseParticipants30Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondarysame day
  • Stroop Color-Word TestPrimarysame day
  • Verbal LearningSecondarysame day
  • Verbal FluencySecondarysame day
  • Symbol CodingSecondarysame day
NCT06901869Start2025PhaseObservationalConditionsParkinson's disease, Aging, frailty and exerciseParticipants50Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal LearningOther outcomesame day
NCT06782724Start2025PhasePhase 2ConditionsParkinson's disease, Multiple sclerosis, Depression and bipolar disorder, Lung diseaseParticipants108Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestOther outcome8 weeks
  • Verbal LearningOther outcome8 weeks
  • Verbal FluencyOther outcome8 weeks
  • Digit Span TestOther outcome8 weeks
  • Symbol CodingOther outcome8 weeks
NCT06688357Start2019PhaseNot applicableConditionsParkinson's diseaseParticipants23Lead sponsorOtherStatusCompleted

Results

Library tests named
  • Verbal LearningSecondary2 weeks
  • Verbal FluencyPrimary2 weeks
  • N-Back TaskSecondary2 weeks
  • Category FluencyPrimary2 weeks
NCT06665113Start2024PhaseNot applicableConditionsParkinson's diseaseParticipants12Lead sponsorOtherStatusRecruitingLibrary tests named
  • Verbal LearningOther outcome1 week
  • Symbol CodingOther outcome1 week
  • Letter-Number Sequencing TaskOther outcome1 week
  • Line Angle MatchingOther outcome1 week
NCT06580977Start2024PhaseNot applicableConditionsParkinson's diseaseParticipants60Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary16 weeks
  • Stroop Color-Word TestSecondary16 weeks
  • Verbal LearningSecondary16 weeks
  • Motor Sequence TaskPrimary16 weeks
NCT06400017Start2024PhaseNot applicableConditionsParkinson's diseaseParticipants60Lead sponsorOtherStatusRecruiting

Paper

Library tests named
  • Trail Making TestPrimary4 weeks
  • Verbal LearningPrimary4 weeks
NCT06399731Start2024PhaseNot applicableConditionsMild cognitive impairment, Parkinson's diseaseParticipants20Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestSecondary
  • Verbal LearningSecondary
  • Verbal FluencySecondary
  • Digit Span TestSecondary
  • Symbol CodingSecondary
  • Tower PlanningSecondary
  • Line Angle MatchingOther outcomesame day
NCT05819008Start2023PhaseObservationalConditionsStroke, Brain injury and concussion, Parkinson's disease, Multiple sclerosis, Cancer, EpilepsyParticipants350Lead sponsorOtherStatusRecruitingLibrary tests named
  • Trail Making TestPrimarysame day
  • Verbal LearningPrimarysame day
  • Verbal FluencyPrimarysame day
  • Corsi Block-Tapping TestPrimarysame day
NCT05635409Start2022PhasePhase 1ConditionsParkinson's diseaseParticipants8Lead sponsorOtherStatusActive, not recruitingLibrary tests named
  • Stroop Color-Word TestSecondary3 years
  • Verbal LearningSecondary3 years
  • Digit Span TestSecondary3 years
  • Category FluencySecondary3 years
  • Picture Naming TestSecondary3 years
NCT05514379Start2022PhaseNot applicableConditionsParkinson's diseaseParticipants50Lead sponsorOtherStatusStatus unknownLibrary tests named
  • Trail Making TestSecondary13 weeks
  • Stroop Color-Word TestSecondary13 weeks
  • Verbal LearningOther outcome13 weeks
  • Verbal FluencyOther outcome13 weeks
  • Digit Span TestOther outcome13 weeks
  • Category FluencyOther outcome13 weeks
  • Tower PlanningSecondary13 weeks
NCT05506891Start2023PhasePhase 2ConditionsParkinson's diseaseParticipants40Lead sponsorOtherStatusStatus unknownLibrary tests named
  • Verbal LearningSecondary13 weeks
  • Digit Span TestSecondary13 weeks
NCT05333549Start2022PhasePhase 2ConditionsParkinson's diseaseParticipants15Lead sponsorOtherStatusCompleted

Results

Library tests named
  • Trail Making TestSecondary6 months
  • Verbal LearningSecondary6 months
  • Verbal FluencySecondary6 months
NCT05218213Start2022PhaseObservationalConditionsParkinson's disease, Aging, frailty and exerciseParticipants133Lead sponsorOtherStatusCompletedLibrary tests named
  • Trail Making TestSecondarysame day
  • Stroop Color-Word TestPrimary
  • Verbal LearningSecondarysame day
  • Verbal FluencySecondarysame day
NCT04878679Start2021PhaseNot applicableConditionsParkinson's diseaseParticipants36Lead sponsorOtherStatusStatus unknown

Paper

Library tests named
  • Trail Making TestPrimary14 weeks
  • Stroop Color-Word TestPrimary14 weeks
  • Verbal LearningPrimary14 weeks

Page 1 of 3

Questions, answered from the data

How many Parkinson's disease trials use Verbal Learning?

61 registered Parkinson's disease studies on ClinicalTrials.gov name it in an outcome measure, 22 of them in a primary outcome: 7% of the condition's 892 studies with a cognitive outcome, against 11% of all of them. It is the 5th most named test in Parkinson's disease trials.

Which tests do Parkinson's disease trials use with Verbal Learning?

Verbal Fluency (33 studies), the Trail Making Test (32 studies) and the Stroop Color-Word Test (21 studies).

How many participants do phase 2 Parkinson's disease trials that use Verbal Learning enroll?

Half of the phase 2 studies that name it enroll 74 participants or fewer, and the middle half enroll 36 to 114. 11 of them give a size.

When do Parkinson's disease trials measure Verbal Learning?

Half of the primary outcomes that name Verbal Learning are measured within 11 weeks of the start, and the middle half from the first day to 6 months. 20 primary outcomes give a duration.

How many completed Parkinson's disease trials that use Verbal Learning have reported results?

16 of the 26 completed studies that name it, 62%, have reported results: 13 posted them on ClinicalTrials.gov, 8 have a results paper linked to the registry record, and 5 did both. The other 10 show neither. Of all completed studies with a cognitive outcome, 46% have reported results.

More on Verbal Learning and Parkinson's disease

  • Every cognitive test in Parkinson's disease trials: 892 studies
  • Verbal Learning in all clinical trials: 1,832 studies

Verbal Learning in other conditions

  • Cancer235
  • Dementia and Alzheimer's224
  • Mild cognitive impairment183
  • Depression and bipolar disorder178
  • Multiple sclerosis139
  • Aging, frailty and exercise128
  • Schizophrenia and psychosis112
  • Brain injury and concussion111
  • Cognitive impairment and decline79
  • Substance use and addiction77
  • Obesity and diabetes74
  • Pain and fatigue72
  • Anxiety, PTSD and OCD70
  • Sleep and sleep disorders66
  • Cardiovascular disease64
  • Stroke63
  • Healthy volunteers56
  • Delirium, surgery and intensive care51

Other tests in Parkinson's disease trials

  • Trail Making Test156
  • Verbal Fluency140
  • Stroop Color-Word Test126
  • Digit Span Test86

How the studies are counted

For each test family, the census runs ClinicalTrials.gov's own outcome search for the family's names and reads every study first posted by the day the family was counted. These studies were read on 10 November 2026. A study counts once on a page, however many tests it names. Counts for a test cover every version of the task under any of its names, so a page can count studies that used a commercial version.

The census adds two things to each record and changes nothing in it: which outcome list names the test (primary, then secondary, then other), and the condition groups, matched on the study's condition names and MeSH terms. A study can fall in several groups; one whose only condition is cognitive impairment or decline falls in “Cognitive impairment and decline”. Studies that name only instruments outside the library count in every total and share but are not listed.

A second read on 10 November 2026 added each study's overall status, whether results are posted, its intervention types, the countries of its sites and the time frame of the outcome that names each test. A time frame counts by the latest time point it names: “Baseline, 12 and 24 weeks” is 24 weeks, a single visit is within a day, and one that names no duration, such as “end of treatment”, is left out of the timings.

A third read on 10 November 2026 added the papers the registry links to each study: those its sponsor lists as reporting results, and those PubMed links to it through the study's NCT number. A study has a results paper when one of them came out in or after the month of its primary completion and PubMed does not class it as a protocol, review or comment. A paper that never gives the NCT number is not linked, so some studies counted as reporting neither did publish.

Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine, which does not endorse these pages. Every study line is in the data release 2.1.0, and the explorer's own file is clinical-trials-studies.json.

The census counts Verbal Learning and Grocery Trip Game as one test family, so this page counts their studies together.

Run Verbal Learning in your trial

Choose tests with a record in registered trials, and run them in a browser at every site, on the same version each visit.

Start free
ConductCognition

Hosted browser-native cognitive testing for academic and commercial research workflows.

A product of ConductScience, Inc.

New tests and features, about once a month. Unsubscribe at any time.

Tests

  • All cognitive tests
  • Test batteries
  • Use and evidence
  • Test norms
  • Trail Making Test
  • N-Back Task
  • Automated scoring
  • Study design
  • New tests by email

Guides

  • Methods and questions
  • Blog
  • Recruitment setup
  • Participant devices
  • Prolific
  • Sona Systems
  • CloudResearch Connect
  • Qualtrics

Use cases

  • Student participant pools
  • Aging and dementia research
  • Clinical trials
  • US clinical research
  • Remote testing

Compare and buy

  • Pricing
  • Compare platforms
  • Offline edition
  • FAQ

Trust

  • Study Quality Monitor
  • HIPAA-ready testing
  • Data export
  • Privacy Policy
  • Terms of Use
  • Data Policy

Company

  • ConductScience
  • Affiliate Program
© 2026 ConductScience, Inc. Research use only.