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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.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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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
What is being tested?
Stimulus Type, Target Presence and Checklist
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

Other trials in United States

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.

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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

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 groups in NCT05272163
Study groupRoleWhat they receive
Main ExperimentExperimentalThis 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.

  1. Accuracy

    Did the Participant get the right answer?

    Measured: Within 1 hour

  2. 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.

  1. First posted9 Mar 2022
  2. Study start17 Jan 2018
  3. Primary completion1 Jan 2024
  4. Study completion1 Jan 2024

Resources

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)
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

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.

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