In a three-year joint project, Dr. Tzu-Yu Hsu at Taipei Medical University (TMU) and Professor Marcus Missal at Université Catholique de Louvain (UCL) are testing relationships between eye movements and mental disorders. With preliminary testing expected to be completed soon, their findings could lead to dramatic changes for psychiatric treatment and mental health policy.
Current psychiatric diagnostic methods are limited due to their subjective nature. As neuroscience progresses, there has been a trend away from reliance on clinicians’ experience and patient reports. Instead, the hope is that diagnoses and treatment decisions can be better informed using objective evidence gained from behavioral, biological and neuroimaging information.
The goal of the researchers at TMU and UCL is to create a precise measure of impulsivity using “visually-guided saccades” [fast eye movements]. Impulsivity is often higher in those with mental illnesses such as severe depression and attention deficit hyperactivity disorder (ADHD). “Premature saccades” occur when subjects’ focus twitches or bounces before the light moves; an objective response that may be associated with pathology or treatment outcomes.
At lab facilities in TMU’s Shuangho Hospital, an initial cohort of 30 subjects and 30 controls were instructed to follow dots that jump across a screen. The recordings will be analyzed alongside four other kinds of data: Electroencephalogram (EEG) readings, magnetic resonance images, questionnaires, and medical records. If eye movements show solid associations with the other data, this method may be eagerly adopted by the medical community as preferable to more expensive, invasive, and subjective measures.
So far, their method appears reliable and could be used in conjunction with other measures of mental disorders. Advantages of measuring saccades include low cost and freedom from subjective bias. Professor Missal praised TMU’s commitment and proactive approach to research as well as patients’ open-mindedness.
Clinicians, scientists, and policymakers have long sought an objective measure for mental problems and treatment outcomes. Professor Missal and Dr. Hsu hope that their method can contribute to psychiatric diagnosis worldwide. If the eye-movement method proves effective, insurers can use the objective criteria obtained from low-cost testing to expand coverage for psychiatric services to people who are currently under-insured due to difficulties with subjective criteria.
Caption: Visually-guided Saccade Testing