Control and description of visual function in research on aphasia and related disorders

Background: Most experimental and assessment tasks in studies of neurogenic language disorders rely on visual information processing. Failure to describe and/or control for visual function may lead to invalid data collection and interpretation. Aims: An empirical study was initiated to describe current practice and needs for improvement in the description of and control for visual acuity, colour perception, visual fields, visual attention, and oculomotor functions. Methods & Procedures: Data were collected from all articles (N = 668) on aphasia (subsequent to left hemisphere damage) and related language disorders (subsequent to TBI and right hemisphere damage) in adults published during a 10-year period in each of 17 journals. Outcomes & Results: Few authors control for or describe even basic aspects of vision. Conclusions: Specific needs and strategies for improvement are discussed. The need for improved continuing education concerning means of screening for various forms of visual function is highlighted. Researchers are encouraged to employ basic screenings corresponding to the visual functions implemented in their assessment and experimental tasks for a given study. Improved feedback to manuscript authors and those seeking grant funding regarding appropriate control for and description of visual function is advocated.