VisionNCT04332783
Isolating and Mitigating Sequentially Dependent Perceptual Errors in Clinical Visual Search
A study testing psychophysics of sequential biases (no drug or patient work) in people with Vision, run by University of California, Berkeley at 1 site in United States.
Trial summary
Remote-store-and-forward teledermatology has recently grown exponentially in popularity and use as an efficient, accurate, and cost-effective way to improve the health and well-being of countless patients. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Vision
- What is being tested?
- psychophysics of sequential biases (no drug or patient work)
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10,120 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2019to 30 Oct 2032
- Phase
- Interventional
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Subjects must have normal or corrected to normal vision with contacts or glasses.
Who cannot join
- Subjects may not be under the age of 18 to participate.
- Subjects may not participate if they are blind.
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, Berkeley
Berkeley, California, 94720
Valerie Ekko, BA, 510 642-5797, vekko@berkeley.edu
About this study
Remote-store-and-forward teledermatology has recently grown exponentially in popularity and use as an efficient, accurate, and cost-effective way to improve the health and well-being of countless patients. Despite advances in machine learning and computer vision, the screening and reading of dermatological images still depends on the visual system of human observers (e.g., clinicians), who receive extensive training to best recognize lesions and anomalies. In remote store-and-forward teledermatology settings, clinicians may examine hundreds of images on a daily basis, seeing several images one after the other. A main underlying assumption of their work is that clinician percepts and decisions about a current image are completely independent from prior viewings. However, we and other groups demonstrated that the visual system has visual serial dependencies (VSDs) at many levels, from perception to decision making, including in clinical tasks. These sequential dependencies, replicated hundreds of times in the literature, mean that what was seen in the past influences (and captures) what is seen and reported at this moment. Theoretically, VSDs are helpful in an autocorrelated natural world, but they are suboptimal in visual tasks conducted in artificial situations where images are not always related. Importantly, serial dependencies in perceptual processing could thus produce significant errors during diagnostic judgments of dermatological images. Our central hypothesis is that VSD can have a disruptive effect in asynchronous remote-store-and-forward teledermatology judgments that impairs accurate detection and recognition of lesions. This hypothesis is supported by our robust pilot data, which show that VSD strongly biases lesion classification in both untrained observers and expert clinicians. The rationale for the proposed research projects is that once it is known how serial dependence arises and how it impacts judgments, we can understand how to control for it. Hence, accuracy of lesion detection and diagnosis can significantly improve. The specific objectives of this proposal are to establish (Aim 1), identify (Aim 2) and mitigate (Aim 3) the impact of VSD on remote-store-and-forward dermatological judgments.
Read the detailed description
Our proposal is designed to investigate the detrimental impact of visual serial dependencies in a remote store and forward teledermatology setting. Serial dependencies likely underlie much of our perceptual experience, but little is known about their negative consequences when dermatologists are tasked with recognizing lesions in remote store and forward teledermatology. The final goal of our research project is to develop recommendation and guidelines to mitigate the negative effect of serial effects in remote store and forward teledermatology, improving accuracy of clinical judgments.
Each experiment will involve a group of observers, dermatologists or untrained observers. Each subject will complete all conditions of the assigned experiment. The procedure will be psychophysical (BESH) across all the experiments. Observers will see images of skin lesions and they will be asked to classify/detect/and recognize features and structures about the lesion images.
- Conditions
- Vision
- Being tested
- psychophysics of sequential biases (no drug or patient work)
- Keywords
- Visual Perception, Psychophysics, Visual Search
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
psychophysics of sequential biases (no drug or patient work)Behavioural
Psychophysical experiment on sequential effects in medical image perception. Observers, including clinicians, perform psychophysical continuous report match-to-sample and forced-choice discrimination judgments of medical images. Observer discrimination accuracy is measured on a trial-wise basis and sequential effects in those judgments are measured. Images can be presented with different interstimulus intervals and in different spatial locations and in different orders. Accuracy, and other signal detection metrics are computed as a function of these factors.
| Study group | Role | What they receive |
|---|---|---|
| Healthy Typical Adults | Experimental | Observers including clinicians and non-clinicians will be asked to participate in computer based tasks in which they visually search for, detect, localize, and categorize medical images. Receives: Behavioral: psychophysics of sequential biases (no drug or patient work) |
| Healthy typical adults | Experimental | Observers including clinicians and non-clinicians will be asked to participate in computer based tasks in which they visually search for, detect, localize, and categorize medical images. Receives: Behavioral: psychophysics of sequential biases (no drug or patient work) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Serial Dependence Assessment using psychophysical procedures
This is a medical image perception experiment using psychophysical methods, including continuous report match-to-sample and method-of-constant stimuli designs. Human observers, including clinicians and untrained observers, are recruited to classify or discriminate medical images. Each observer participates in approximately 300 trials in a session. On each trial, observers view a medical image on a computer monitor and are asked to make either a match-to-sample or a two-alternative forced choice decisions about the image. Observer responses on each trial are classified in terms of their accuracy. Outcome measures include hit rate, false alarm rate, sensitivity, selectivity, d', and criterion. Changes in these metrics from trial-to-trial throughout the course of the experiment are quantified as metrics of sequential biases that might be present in observer judgments.
Measured: Each participant is tested for 30-60 minutes in a psychophysical experiment.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Apr 2020
- Study start1 Apr 2019
- Primary completion30 Jun 2031 (estimated)
- Study completion30 Oct 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for VisionStudies of the same condition, open and under way.
- 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
- Randomised
- Intervention model
- Single group
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 10,120 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of California, Berkeley
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, David Whitney, University of California, Berkeley
- Investigators
- David Whitney, PhD, Principal investigator, University of California, Berkeley
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04332783
- Sponsor's protocol ID
- R01CA236793
- Status last verified
- Jan 2026
- First submitted
- 31 Mar 2020
- Last updated
- 3 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified participant data may be shared with other researchers who are interested or when peer-reviewed journals require this. The data will be anonymized and will not be linked to any individual participant identity.
Study at a glance
From the registry record, last updated by the sponsor on 3 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Isolating and Mitigating Sequentially Dependent Perceptual Errors in Clinical Visual Search
- ClinicalTrials.gov ID
- NCT04332783
- Acronym / sponsor ID
- R01CA236793
- Conditions
- Vision
- Keywords
- Visual Perception, Psychophysics, Visual Search
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 10,120 participants (estimated)
- Lead sponsor
- University of California, BerkeleyUniversity, hospital or other
- Study start
- 1 Apr 2019 (actual)
- Primary completion
- 30 Jun 2031 (estimated)
- Study completion
- 30 Oct 2032 (estimated)
- First posted
- 3 Apr 2020 (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.
Remote-store-and-forward teledermatology has recently grown exponentially in popularity and use as an efficient, accurate, and cost-effective way to improve the health and well-being of countless patients. Despite advances in machine learning and computer vision, the screening and reading of dermatological images still depends on the visual system of human observers (e.g., clinicians), who receive extensive training to best recognize lesions and anomalies. In remote store-and-forward teledermatology settings, clinicians may examine hundreds of images on a daily basis, seeing several images one after the other. A main underlying assumption of their work is that clinician percepts and decisions about a current image are completely independent from prior viewings. However, we and other groups demonstrated that the visual system has visual serial dependencies (VSDs) at many levels, from perception to decision making, including in clinical tasks. These sequential dependencies, replicated hundreds of times in the literature, mean that what was seen in the past influences (and captures) what is seen and reported at this moment. Theoretically, VSDs are helpful in an autocorrelated natural world, but they are suboptimal in visual tasks conducted in artificial situations where images are not always related. Importantly, serial dependencies in perceptual processing could thus produce significant errors during diagnostic judgments of dermatological images. Our central hypothesis is that VSD can have a disruptive effect in asynchronous remote-store-and-forward teledermatology judgments that impairs accurate detection and recognition of lesions. This hypothesis is supported by our robust pilot data, which show that VSD strongly biases lesion classification in both untrained observers and expert clinicians. The rationale for the proposed research projects is that once it is known how serial dependence arises and how it impacts judgments, we can understand how to control for it. Hence, accuracy of lesion detection and diagnosis can significantly improve. The specific objectives of this proposal are to establish (Aim 1), identify (Aim 2) and mitigate (Aim 3) the impact of VSD on remote-store-and-forward dermatological judgments.
Detailed description
Our proposal is designed to investigate the detrimental impact of visual serial dependencies in a remote store and forward teledermatology setting. Serial dependencies likely underlie much of our perceptual experience, but little is known about their negative consequences when dermatologists are tasked with recognizing lesions in remote store and forward teledermatology. The final goal of our research project is to develop recommendation and guidelines to mitigate the negative effect of serial effects in remote store and forward teledermatology, improving accuracy of clinical judgments.
Each experiment will involve a group of observers, dermatologists or untrained observers. Each subject will complete all conditions of the assigned experiment. The procedure will be psychophysical (BESH) across all the experiments. Observers will see images of skin lesions and they will be asked to classify/detect/and recognize features and structures about the lesion images.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Healthy Typical Adults | Experimental | Behavioral: psychophysics of sequential biases (no drug or patient work)Observers including clinicians and non-clinicians will be asked to participate in computer based tasks in which they visually search for, detect, localize, and categorize medical images. |
| Healthy typical adults | Experimental | Behavioral: psychophysics of sequential biases (no drug or patient work)Observers including clinicians and non-clinicians will be asked to participate in computer based tasks in which they visually search for, detect, localize, and categorize medical images. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Subjects must have normal or corrected to normal vision with contacts or glasses.
Key exclusion criteria (2 listed)
- Subjects may not be under the age of 18 to participate.
- Subjects may not participate if they are blind.
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 |
|---|---|---|
| psychophysics of sequential biases (no drug or patient work)Psychophysical experiment on sequential effects in medical image perception. Observers, including clinicians, perform psychophysical continuous report match-to-sample and forced-choice discrimination judgments of medical images. Observer discrimination accuracy is measured on a trial-wise basis and sequential effects in those judgments are measured. Images can be presented with different interstimulus intervals and in different spatial locations and in different orders. Accuracy, and other signal detection metrics are computed as a function of these factors. | Behavioural | Healthy Typical Adults, Healthy typical adults |
Primary outcome
Serial Dependence Assessment using psychophysical procedures
Time frame: Each participant is tested for 30-60 minutes in a psychophysical experiment.
This is a medical image perception experiment using psychophysical methods, including continuous report match-to-sample and method-of-constant stimuli designs. Human observers, including clinicians and untrained observers, are recruited to classify or discriminate medical images. Each observer participates in approximately 300 trials in a session. On each trial, observers view a medical image on a computer monitor and are asked to make either a match-to-sample or a two-alternative forced choice decisions about the image. Observer responses on each trial are classified in terms of their accuracy. Outcome measures include hit rate, false alarm rate, sensitivity, selectivity, d', and criterion. Changes in these metrics from trial-to-trial throughout the course of the experiment are quantified as metrics of sequential biases that might be present in observer judgments.
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 3 Feb 2026.
- Individual participant dataSharing planned: Yes. De-identified participant data may be shared with other researchers who are interested or when peer-reviewed journals require this. The data will be anonymized and will not be linked to any individual participant identity.
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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.
David Whitney, PhD principal investigator
University of California, Berkeley
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing psychophysics of sequential biases (no drug or patient work) in people with Vision, run by University of California, Berkeley 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: looking for participants now, as of the sponsor's last update on 3 Feb 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. 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?
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 Katrina Wolters, BA (510-642-5797, katrinaw@berkeley.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serial Dependence Assessment using psychophysical procedures (time frame: Each participant is tested for 30-60 minutes in a psychophysical experiment.). 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 3 Feb 2026.