The Effect of Visual Impairment on the Controllability of a Brain-Computer Interface Using Visual Spatial Attention

A brain-computer interface (BCI) aims to generate control signals from brain activity, independent of physical movement or gaze shifts. Earlier studies revealed that attentional selection of peripheral objects can control a BCI, but this requires sufficient visual acuity to recognize the target stimulus reliably. This study systematically examined how visual impairments, such as blurred or monocular vision, affect event-related potentials (ERPs) and BCI performance in healthy participants directing covert attention to peripheral visual stimuli.

The researchers expected visual impairments to alter attention-related visual ERPs but expected minimal or no impact on BCI performance when color is the target feature.

Comparing binocular vision to monocular vision, the study found differences in early attention-sensitive visual components. Simulated vision degradation led to a reduction in ERPs within the P300 range. However, these differences in ERPs across vision conditions did not affect the BCI's decoding accuracy. The findings not only highlight variations in visual ERPs in different viewing conditions but primarily demonstrate that a BCI can be reliably controlled by focusing attention on a visual stimulus, even with visual impairments.

The color of the stimulus is crucial for recognition, regardless of visual impairment. This research provides a promising approach to enable paralyzed individuals to communicate using a non-invasive, gaze-independent BCI.