grayscale phone friction
This evidence decision is attached to the maintained Brali entry above. The public protocol may be narrowed, reviewed, or kept practical according to the decision.
Evidence Ledger · Protocol candidate · reviewed 2026-09-11
A cross-over feasibility trial of smartphone grayscale mode in medical students
The reviewed source can support a conservative practical protocol.
Brali decision: Protocol candidate. This page summarizes a reviewed evidence boundary; it does not reproduce the source and it does not turn one paper into a universal prescription.
What the source supports
For a person who already wants to reduce habitual smartphone use, grayscale is a reasonable low-cost, reversible experiment. In this small short cross-over trial, grayscale was associated with about 28 fewer minutes of daily phone screen time on average. The result supports a screen-time-friction protocol, not a productivity, sleep, mental-health, or durable behavior-change claim.
What it does not establish
- Grayscale reliably improves productivity or sleep.
- Grayscale treats problematic smartphone use or mental-health conditions.
- Everyone will reduce phone use by about 28 minutes per day.
- One week is an optimal or necessary duration.
- Lower phone screen time necessarily means less total digital distraction rather than substitution to another device.
Important limitations
- Small single-school sample of first-year medical students.
- Short two-week study with one week per condition and no washout period.
- Participants and investigators could not blind the visible display condition.
- Screen-time values were participant-reported from built-in device trackers without screenshot verification.
- Exploratory productivity and sleep measures were non-validated and not powered for formal inference.
- Qualitative comments described color-dependent usability problems and substitution to other devices.
Source context
A cross-over feasibility trial of smartphone grayscale mode in medical students
- Source type: primary-study
- Design: Two-week cross-over feasibility trial with consecutive one-week grayscale and color conditions. Assignment used a balanced alternating sequence based on enrollment order; participants served as their own controls. Mixed-effects models analyzed repeated daily screen-time observations.
- Population: First-year medical students at one US allopathic medical school. Sixty-one enrolled and 51 completed both study phases.
- Exposure / intervention: Smartphone display set to grayscale for one week versus normal color for one week. Participants transcribed daily screen-time values from their device's built-in tracking feature and completed exploratory end-of-week surveys.
- Outcomes: Daily smartphone screen time; Exploratory self-reported productivity; Exploratory self-reported sleep quality; Feasibility and qualitative usability feedback
Citation: Hagerty J, Saretha S, Phung B, et al. Front Digit Health. 2026;8:1816095.
DOI: 10.3389/fdgth.2026.1816095
What this changes in Brali
Editorial note: Publish as a reversible interface nudge. Track the actual target behavior and substitution, allow color for functional tasks, and do not use broad digital-detox language.
Use the boundary, not just the headline
When an AI agent or a person retrieves this decision, preserve both the supported claim and the unsupported or overstated claims. Dropping the boundary would turn a reviewed source into a stronger claim than Brali actually maintains.
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