Eye Tracking as a Tool to Identify Mood in Aphasia: A Feasibility Study
Background. Persons with aphasia often present with low mood/depression, which can negatively affect their quality of life. The validity and reliability of existing depression measures for aphasia have been called into question. Eye tracking in nonstroke populations is reliable in identifying low mood/depression. Depressed persons are biased to negative emotions compared with nondepressed persons and have an absence of bias to positive emotions. However, nondepressed persons may be biased to positive emotions. Objective. To examine the feasibility of using eye tracking to measure mood in persons with aphasia. Methods. We recruited 22 persons with chronic aphasia and 12 healthy controls. Participants completed 2 self-report measures of mood. They also viewed faces that showed happy, sad, and neutral facial expressions during eye tracking. We analyzed 2 eye tracking indices: initial gaze orientation and gaze maintenance to happy, sad, and neutral faces. Results. For initial gaze orientation, participants with aphasia fixated faster on emotional faces compared with healthy controls but directed their gaze less often to happy faces compared with healthy controls. For gaze maintenance components, the duration of first fixation and total fixation duration were shorter on sad faces for participants with aphasia compared with healthy controls. Conclusion. Use of eye tracking with faces representing different mood states is feasible in persons with aphasia. Although there were some similarities, participants with aphasia had different gaze patterns to emotional faces compared with healthy controls. Further research is needed to establish whether this is a valid and reliable method of mood assessment.