The Role of Fixation in Visual Attention Performance

BACKGROUND: Attending information presented in the peripheral visual field is crucial for many tasks, such as car driving and playing sports. A substantial body of research addresses the performance in detecting visual information across the visual field. However, there is a lack of studies presenting targets in a naturalistic visual environment and controlling the location of fixation by recording gaze objectively. The present study aims to close this gap and contribute to the knowledge on role of retinal periphery in information processing.

METHOD: Central and peripheral targets were presented on a dynamic background consisting of car driving, as seen from the position of the driver. Targets consisted of six-digit numbers presented for 200 ms, either in the central visual field or at a ± 15.3° periphery on the horizontal meridian. The acuity demand of the target was 0.1, exceeding peripheral acuity. In 50% of cases, the target included the digit "3". Participants were instructed to report as quickly and accurately as possible, whether or not the presented number included the digit "3". While performing the test, the gaze of participants was recorded with a commercial device. Correct and incorrect responses were analysed separately for responses occurring while the target was fixated and responses given without fixation of the target.

RESULTS: Participants were 53% female with a mean (SD) age of 29.7 (1.6) years. Number of correctly detected targets was found to be significantly higher (p < 0.0001, binomial test, two-tailed) than the number of targets reported incorrectly, no matter whether the target was fixated or not.

CONCLUSIONS: Findings from this study suggest that target recognition in a naturalistic environment operates in the central and in the peripheral visual field as well, provided the acuity demand of the target exceeds the acuity of the peripheral visual field. Fixation of the target is beneficial for performance but not required. Further studies will explore whether patients with central vision loss improve their peripheral visual processing as a compensatory mechanism.