Eye Tracking Offers New Clues About Cannabis Attention Bias

A cannabis photograph can attract attention for many reasons: familiarity, curiosity, personal experience, or an urge to consume. Understanding which explanation applies is challenging, especially when the research tool captures only a quick button press.

A new Dalhousie University study compared three ways of measuring attention to cannabis images and found that the choice of test mattered.¹ Eye tracking revealed patterns associated with cannabis use severity that a conventional reaction-time task missed. A browser-based cursor tool captured some similar patterns, although with less precision.

The findings suggest a constructive direction for cannabis research: better measurement could help scientists understand how people respond to cannabis cues and evaluate interventions more carefully. However, this small study does not establish an addiction screening test or demonstrate that cannabis causes attention impairment.

What Cannabis Attention Bias Actually Means

Attentional bias describes a tendency to direct attention toward particular information. Someone interested in gardening might notice plants in a crowded photograph. A person anticipating dinner might linger over food images. Cannabis research examines whether cannabis-related objects similarly attract or hold attention.

One theory proposes that repeated substance use can make associated sights and situations more motivationally significant. Researchers investigate whether this contributes to continued consumption or difficulty changing established habits.

Attention, craving, and behaviour nevertheless remain different things. Looking at a cannabis image does not establish that someone wants to consume, has lost control of consumption, or meets criteria for cannabis use disorder. The useful question is whether a particular attention pattern helps explain something beyond the image itself.

How the Cannabis Study Compared Three Attention Tests

The researchers recruited 31 participants aged 15–25. Sixteen reported using cannabis at least weekly during the previous three months, while 15 had never used it. Everyone completed three tasks during an in-person experimental session.

Dot-Probe Reaction-Time Testing

The dot-probe task briefly displayed a cannabis image alongside a neutral image. A probe then appeared where one image had been, and participants responded as quickly as possible. Differences in response speed were used to infer where attention had been directed.

This approach measures attention indirectly. A response time combines several processes, including noticing the probe, deciding what to do, and executing a movement. Small differences can therefore be difficult to interpret.

Eye Tracking During Free Viewing

The eye-tracking task recorded participants’ gaze while they viewed cannabis and neutral images. Rather than inferring attention from a later response, it measured where people looked and how long they remained there.

This continuous record can capture sustained engagement that a single reaction-time measurement may overlook.

MouseView.js Cursor Tracking

MouseView.js presented blurred images that participants explored by moving a cursor to reveal small areas. The time spent revealing different regions served as a proxy for visual attention.

The approach could support more accessible online research without specialized eye-tracking equipment. However, moving a mouse involves deliberate exploration, so it cannot be assumed to reproduce every aspect of eye movement.

What the Cannabis Attention Study Found

Eye tracking and MouseView.js identified differences in how the groups distributed attention. The dot-probe task did not detect significant effects of stimulus type, group, or their interaction.

The table below summarizes findings reported in the paper.

The direction of the result deserves attention. Both groups generally spent longer on neutral images than cannabis images. Cannabis users showed a smaller neutral-image preference, rather than a straightforward preference for cannabis over everything else.

That distinction prevents an exaggerated conclusion. The study suggests relative differences in engagement with cannabis cues, not an irresistible visual attraction shared by everyone who uses cannabis.

Why Attention and Cannabis Craving Need Separate Measurements

None of the three tasks detected significant associations with individual differences in craving. This limits any claim that a gaze pattern directly reveals how strongly someone wants cannabis.

The timing of measurement may matter. Craving was assessed independently of cue exposure, rather than repeatedly during or immediately after the image tasks. Future studies could examine whether changes in attention coincide with changes in craving.

Separate 2026 research on cannabis craving profiles examined craving across multiple treatment and follow-up assessments. That approach illustrates why repeated measurements can add information that a single score cannot provide.

A useful next step would combine repeated gaze measurements, contemporaneous craving reports, and later consumption outcomes. Researchers could then test whether attention predicts meaningful changes instead of assuming the connection.

Better Measurement Could Strengthen Cannabis Treatment Research

Some experimental interventions attempt to train attention away from substance-related cues. The proposed benefit is that changing habitual responses might help people manage triggers. Establishing that benefit requires more than showing improvement on the training task.

Consider a hypothetical programme that teaches participants to respond faster to neutral images. Better performance could reflect practice with that particular exercise. It would not automatically demonstrate fewer cravings, reduced cannabis consumption, or improved daily functioning.

This creates a practical research opportunity. Eye tracking could provide an additional measurement of whether attention changes, while independent assessments establish whether those changes matter outside the laboratory.

Useful outcomes would include:

• Whether attention changes persist beyond the testing session.
• Whether those changes accompany reduced cannabis-related difficulties.
• Whether participants experience improvements in everyday functioning.

MyCannabis coverage of attachment-based therapy for adolescent cannabis use offers a complementary perspective. Treatment research also needs to consider coping skills, relationships, and engagement. Attention measurements could contribute to that wider picture without replacing it.

Can Browser Tools Make Cannabis Research More Accessible?

MouseView.js offers an appealing possibility: studies that reach people who cannot easily visit a specialist laboratory. That could help researchers recruit beyond nearby universities and investigate a wider range of experiences.

Earlier MouseView.js validation research established its potential for certain web-based attention experiments. The cannabis study adds a narrower lesson: usefulness in one setting does not guarantee equivalent performance for every research question.

Eye tracking and cursor tracking showed only a small positive association between their attention indices. Their overlap should therefore not be treated as interchangeability.

A sensible future design could use browser tools for broad recruitment and repeated observations, alongside eye tracking in a smaller validation sample. That remains a proposal to test. Importantly, the present study administered MouseView.js in person, so it did not establish how well this cannabis task performs in participants’ homes.

Why the Cannabis Findings Still Need Replication

The sample was small, and the groups differed in age, sex, education, and ethnicity. Statistical adjustment attempted to account for those differences, but it cannot guarantee that the observed patterns specifically reflect cannabis use.

Participants were recruited from the community rather than a clinical treatment population. The findings therefore cannot establish how the tasks perform among people diagnosed with cannabis use disorder.

There is also a comparison problem: the tests capture partly different processes. Reaction-time testing, gaze allocation, and purposeful cursor exploration are related activities, but they are not identical measurements of one underlying ability.

This reflects a broader challenge discussed in MyCannabis reporting on how tobacco history complicates cannabis research: the comparison group and the variables measured can substantially shape the interpretation. Better cannabis science requires more specific questions as well as more sophisticated instruments.

A More Precise Future for Cannabis Attention Research

The most promising contribution of this study is methodological. It suggests that sustained looking behaviour may reveal information that conventional reaction-time testing misses under these experimental conditions.

Larger, more balanced studies can now examine whether those patterns replicate, remain stable over time, and predict outcomes that matter to people seeking support. Browser tools could expand participation, while laboratory measurements help establish what those tools actually capture.

Progress does not require turning every eye movement into a diagnosis. It requires connecting careful measurements with clear questions. That approach could produce cannabis research that is more accessible, more informative, and ultimately more useful for improving care.

References:

¹ Yildirim, S. D., Banire, B., Sutherland, D., McGowan, Y., Stewart, S. H., Klein, R. M., & Meier, S. M. (2027). Comparison of visual tasks for assessing attentional bias in cannabis users and non-users. Addictive Behaviors, 185, 108879. https://doi.org/10.1016/j.addbeh.2026.108879