Incidental FindingsNCT05272163
Brief Title: Project 4 Example: Mixed Hybrid Checklist
A study testing Stimulus Type, Target Presence and Checklist in people with Incidental Findings and Visual Attention, run by Brigham and Women's Hospital at 1 site in United States.
Trial summary
In "Mixed Hybrid Search", participants look for 3 specific target (e.g. this boot, this cat, this hat) and 3 categorical items (ANY fruit, ANY car, ANY game). In this task, participants tend to miss many categorical items. This is analogous to radiologists missing "incidental findings" when reading medical images. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Incidental Findings, Visual Attention, Visual Search
- What is being tested?
- Stimulus Type, Target Presence and Checklist
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Jan 2018to 1 Jan 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- All welcome to enroll
Who cannot join
- excluded if Participant fails Ishihara color vision test
- excluded if Participant has acuity worse than 20/25 with correction
Trial locations and contacts
1 site in 1 country.
United States1 site
Visual Attention Lab / Brigham and Women's Hospital
Boston, Massachusetts, 02215
About this study
Official title: Project 4 Example: Mixed Hybrid Checklist
In "Mixed Hybrid Search", participants look for 3 specific target (e.g. this boot, this cat, this hat) and 3 categorical items (ANY fruit, ANY car, ANY game). In this task, participants tend to miss many categorical items. This is analogous to radiologists missing "incidental findings" when reading medical images. In this experiment, participants were given a checklist to help them to find categorical targets.
Read the detailed description
This experiment is one member of a 'bundle' of BESH experiments that were registered as part of the grant application process. It is not possible or meaningful to register a bundle of experiments in a single CT.gov filing so "Mixed Hybrid Checklist" is being registered as an example of this bundle.
This is the text of the pre-registration of Mixed Hybrid Checklist that was originally placed on the Open Science Framework: https://osf.io/j6h4s
NOTE: Since the pronoun comment is advisory, we will leave this for later. The website is, indeed, a functioning OSF page.
========
What's the main question being asked or hypothesis being tested in this study?
In real world search (and, notably, in radiology), it can be important to keep "an eye out" for items of interest that are not the primary subject of the search. In radiology these are known as "incidental findings," and they are a significant issue because clinicians are expected to detect items of clinical importance even they are answering a different question (e.g. you need to detect pneumonia even if your task was to screen for lung cancer). We have developed a "model system," in the form of a 'mixed hybrid search' task that can be used to investigate the fundamental cognitive processes that lie behind incidental finding errors. In this mixed hybrid search task, observers search for any one of multiple specific targets (e.g., this rabbit, this truck, and this spoon) and multiple categorical targets (e.g. any masks, furniture, and plants). In the all of the 'mixed hybrid search' experiments conducted thus far, the categorical targets are missed at a much higher rate than the specific targets. The categorical targets, thus, become the analog of the incidental error and our goal is to reduce those errors in our model system in the hope that this will provide guidance as to how to reduce errors in real-world tasks.
We have tested two strategies intended to reduce the number of missed categorical targets. In Experiment 5, we reminded observers about the categorical targets via non-search trials in which categorical targets were clearly marked. In Experiment 6, we forced observers to respond twice on each trial: Once to confirm the presence or absence of specific targets, and once to confirm the presence or absence of categorical targets. Both of these interventions failed.
This 'Hybrid Checklist' experiment is another attempt to develop a strategy that helps us reduce these categorical errors. Like the previous experiments, observers begin by memorizing three specific targets and three categorical targets. After viewing the targets, observers must pass an old/new recognition test with 100% correct responses to move to the search phase. Each memory test consists of 2×N items where N is the memory set size, and 50% of the items are old (targets) and 50% are new. Having passed the memory test, observers search for their targets in displays with 4, 8, or 12 items. Observers must indicate whether each target in the memory set is present or absent in the current display by clicking with a mouse. There are 6 targets (3 specific, 3 categorical), so observers make 6 responses on each trial. Error and reaction time will be recorded for each click, and for each trial.
Hypothesis (H1):
- We hypothesize that this checklist procedure will improve accuracy and reduce miss errors. However, given that there are 6 responses on each trial, the time per trial (or time per case for radiologists) is likely to increase significantly.
Describe the key dependent variable(s) specifying how they will be measured.
Miss errors and reaction times are the key dependent variables. These will be averaged across trials of the same condition (specific target, categorical target, and absent trials) and visual set size (4, 8, 12). Note that these measures will be compared to results from previous experiments rather than a within-observer design.
How many and which conditions will participants be assigned to?
In this experiment, participants are assigned to a single, 'checklist' condition. All observers memorize a set of three specific and three categorical targets. They are then required to pass a memory test before moving on to perform 20 practice trials and 300 experimental trials of the visual search task. Of these 300 trials:
70% are target-present trials 45% of target-present trials will have one target
- 80% of one-target trials have one specific target
- 20% of one-target trials have one categorical target 25% of target-present trials will have two targets
- 65% of two-target trials have two specific targets
- 5% of two-target trials have two categorical targets
- 30% of two-target trials have one specific and one categorical target The remaining 30% of trials will have no targets
Specify exactly which analyses you will conduct to examine the main question/hypothesis.
Reaction time and error rate will be compared to those in the previous mixed hybrid search experiment - a between-subjects design (Wolfe, Soce, and Schill, 2017). Analyses will be performed on both reaction time and miss error rate. For reaction time, a repeated measures ANOVA will be run with two factors: condition (specific target, categorical target, and absent) and visual set size. For the miss error rate, statistical analysis of errors will be performed on arcsine transformed error rates (Hogg \& Craig, 1995).
Any secondary analyses?
We will explore the data for other patterns of interest: E.g.
- Order effects: Does a categorical target on trial N influence the probability of detecting such a target on N+1.
How many observations will be collected or what will determine sample size? No need to justify decision, but be precise about exactly how the number will be determined.
To be consistent with the previous 'Mixed Hybrid Search' experiments, we will collect data from 12 observers. Participants are excluded if they are not between the ages of 18 and 55, if their visual acuity is worse than 20/25, or if they do not pass the Ishihara Color Test.
Anything else you would like to pre-register? (e.g., data exclusions, variables collected for exploratory purposes, unusual analyses planned?)
N/A
- Conditions
- Incidental Findings, Visual Attention, Visual Search, Hybrid Search
- Being tested
- Stimulus Type, Target Presence, Checklist
- Keywords
- visual perception, BESH, visual search, errors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Stimulus TypeBehavioural
Targets can be specific or categorical
Target PresenceBehavioural
There is or is not a target present on each trial
ChecklistBehavioural
In fact, there is a checklist on every trial but these results will be compared to a non-checklist condition from another experiment
| Study group | Role | What they receive |
|---|---|---|
| Main Experiment | Experimental | This is a single arm study where all participants are tested on 1-2 hours of visual search. Receives: Behavioral: Stimulus Type; Behavioral: Target Presence; Behavioral: Checklist |
What is being measured
The primary outcome is the main question the study is designed to answer.
Accuracy
Did the Participant get the right answer?
Measured: Within 1 hour
Response Time (RT)
How long did it take to respond on each trial?
Measured: Within 1 hour
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Mar 2022
- Study start17 Jan 2018
- Primary completion1 Jan 2024
- Study completion1 Jan 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Incidental FindingsStudies of the same condition, open and under way.
- More trials run by Brigham and Women's HospitalThe 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 N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 12 participants (actual)
Sponsor and investigators
- Lead sponsor
- Brigham and Women's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jeremy M Wolfe, PhD, Brigham and Women's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05272163
- Sponsor's protocol ID
- 2007P000646-C
- Status last verified
- Feb 2025
- First submitted
- 18 Feb 2022
- Last updated
- 19 Feb 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified raw data and other materials will be posted on the OSF site for the experiment
Study at a glance
From the registry record, last updated by the sponsor on 19 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Project 4 Example: Mixed Hybrid Checklist
- ClinicalTrials.gov ID
- NCT05272163
- Acronym / sponsor ID
- 2007P000646-C
- Conditions
- Incidental Findings, Visual Attention, Visual Search, Hybrid Search
- Keywords
- visual perception, BESH, visual search, errors
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants (actual)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Study start
- 17 Jan 2018 (actual)
- Primary completion
- 1 Jan 2024 (actual)
- Study completion
- 1 Jan 2024 (actual)
- First posted
- 9 Mar 2022 (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.
In "Mixed Hybrid Search", participants look for 3 specific target (e.g. this boot, this cat, this hat) and 3 categorical items (ANY fruit, ANY car, ANY game). In this task, participants tend to miss many categorical items. This is analogous to radiologists missing "incidental findings" when reading medical images. In this experiment, participants were given a checklist to help them to find categorical targets.
Detailed description
This experiment is one member of a 'bundle' of BESH experiments that were registered as part of the grant application process. It is not possible or meaningful to register a bundle of experiments in a single CT.gov filing so "Mixed Hybrid Checklist" is being registered as an example of this bundle.
This is the text of the pre-registration of Mixed Hybrid Checklist that was originally placed on the Open Science Framework: https://osf.io/j6h4s
NOTE: Since the pronoun comment is advisory, we will leave this for later. The website is, indeed, a functioning OSF page.
========
What's the main question being asked or hypothesis being tested in this study?
In real world search (and, notably, in radiology), it can be important to keep "an eye out" for items of interest that are not the primary subject of the search. In radiology these are known as "incidental findings," and they are a significant issue because clinicians are expected to detect items of clinical importance even they are answering a different question (e.g. you need to detect pneumonia even if your task was to screen for lung cancer). We have developed a "model system," in the form of a 'mixed hybrid search' task that can be used to investigate the fundamental cognitive processes that lie behind incidental finding errors. In this mixed hybrid search task, observers search for any one of multiple specific targets (e.g., this rabbit, this truck, and this spoon) and multiple categorical targets (e.g. any masks, furniture, and plants). In the all of the 'mixed hybrid search' experiments conducted thus far, the categorical targets are missed at a much higher rate than the specific targets. The categorical targets, thus, become the analog of the incidental error and our goal is to reduce those errors in our model system in the hope that this will provide guidance as to how to reduce errors in real-world tasks.
We have tested two strategies intended to reduce the number of missed categorical targets. In Experiment 5, we reminded observers about the categorical targets via non-search trials in which categorical targets were clearly marked. In Experiment 6, we forced observers to respond twice on each trial: Once to confirm the presence or absence of specific targets, and once to confirm the presence or absence of categorical targets. Both of these interventions failed.
This 'Hybrid Checklist' experiment is another attempt to develop a strategy that helps us reduce these categorical errors. Like the previous experiments, observers begin by memorizing three specific targets and three categorical targets. After viewing the targets, observers must pass an old/new recognition test with 100% correct responses to move to the search phase. Each memory test consists of 2×N items where N is the memory set size, and 50% of the items are old (targets) and 50% are new. Having passed the memory test, observers search for their targets in displays with 4, 8, or 12 items. Observers must indicate whether each target in the memory set is present or absent in the current display by clicking with a mouse. There are 6 targets (3 specific, 3 categorical), so observers make 6 responses on each trial. Error and reaction time will be recorded for each click, and for each trial.
Hypothesis (H1):
- We hypothesize that this checklist procedure will improve accuracy and reduce miss errors. However, given that there are 6 responses on each trial, the time per trial (or time per case for radiologists) is likely to increase significantly.
Describe the key dependent variable(s) specifying how they will be measured.
Miss errors and reaction times are the key dependent variables. These will be averaged across trials of the same condition (specific target, categorical target, and absent trials) and visual set size (4, 8, 12). Note that these measures will be compared to results from previous experiments rather than a within-observer design.
How many and which conditions will participants be assigned to?
In this experiment, participants are assigned to a single, 'checklist' condition. All observers memorize a set of three specific and three categorical targets. They are then required to pass a memory test before moving on to perform 20 practice trials and 300 experimental trials of the visual search task. Of these 300 trials:
70% are target-present trials 45% of target-present trials will have one target
- 80% of one-target trials have one specific target
- 20% of one-target trials have one categorical target 25% of target-present trials will have two targets
- 65% of two-target trials have two specific targets
- 5% of two-target trials have two categorical targets
- 30% of two-target trials have one specific and one categorical target The remaining 30% of trials will have no targets
Specify exactly which analyses you will conduct to examine the main question/hypothesis.
Reaction time and error rate will be compared to those in the previous mixed hybrid search experiment - a between-subjects design (Wolfe, Soce, and Schill, 2017). Analyses will be performed on both reaction time and miss error rate. For reaction time, a repeated measures ANOVA will be run with two factors: condition (specific target, categorical target, and absent) and visual set size. For the miss error rate, statistical analysis of errors will be performed on arcsine transformed error rates (Hogg \& Craig, 1995).
Any secondary analyses?
We will explore the data for other patterns of interest: E.g.
- Order effects: Does a categorical target on trial N influence the probability of detecting such a target on N+1.
How many observations will be collected or what will determine sample size? No need to justify decision, but be precise about exactly how the number will be determined.
To be consistent with the previous 'Mixed Hybrid Search' experiments, we will collect data from 12 observers. Participants are excluded if they are not between the ages of 18 and 55, if their visual acuity is worse than 20/25, or if they do not pass the Ishihara Color Test.
Anything else you would like to pre-register? (e.g., data exclusions, variables collected for exploratory purposes, unusual analyses planned?)
N/A
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Main Experiment | Experimental | Behavioral: Stimulus Type, Behavioral: Target Presence, Behavioral: ChecklistThis is a single arm study where all participants are tested on 1-2 hours of visual search. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- All welcome to enroll
Key exclusion criteria (2 listed)
- excluded if Participant fails Ishihara color vision test
- excluded if Participant has acuity worse than 20/25 with correction
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 |
|---|---|---|
| Stimulus TypeTargets can be specific or categorical | Behavioural | Main Experiment |
| Target PresenceThere is or is not a target present on each trial | Behavioural | Main Experiment |
| ChecklistIn fact, there is a checklist on every trial but these results will be compared to a non-checklist condition from another experiment | Behavioural | Main Experiment |
Primary outcome
Accuracy
Time frame: Within 1 hour
Did the Participant get the right answer?
Response Time (RT)
Time frame: Within 1 hour
How long did it take to respond on each trial?
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Feb 2025.
- Individual participant dataSharing planned: Yes. De-identified raw data and other materials will be posted on the OSF site for the experiment
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Stimulus Type, Target Presence and Checklist in people with Incidental Findings and Visual Attention, run by Brigham and Women's Hospital 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 1 inclusion and 2 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: finished, as of the sponsor's last update on 19 Feb 2025. 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. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Accuracy (time frame: Within 1 hour). The study lists 2 primary outcomes in all. 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 19 Feb 2025; AzTrials last refreshed its copy on 30 Oct 2026.