Effects of lateralized light flash and color on unilateral neglect

Abstract

Purpose: Bottom-up-based sensory stimulation has been useful in promoting recovery from post-stroke neglect. Light and color are salient stimuli for guiding our orienting behaviors and influence the degree of spatial bias. This study evaluated the effects of lateralized light flash and color on spatial bias in unilateral neglect (UN). Method: We enrolled 15 individuals with UN as a consequence of a right hemispheric stroke of less than 65 d. This was a 3 × 3 design study with three conditions of lens color (colorless, red, and blue) and three conditions of flash light locations (no flash, left, and right). Results: All participants showed a decrease in ipsilesional spatial bias under left-side light flash and a red lens. Right-side light flash and a blue lens induced more rightward bias than other conditions. Conclusions: This evidence confirms the use of sensory stimulation to complement post-stroke UN remediation. Lateralized light flash to the contralesional space and red-colored lenses have beneficial effects on amelioration of UN, whereas ipsilesional light flash and the color blue may exacerbate ipsilesional spatial bias in stroke survivors with UN.

Implications for Rehabilitation

• Contralesional light flash and the color red may ameliorate ipsilesional spatial bias in stroke survivors with unilateral neglect (UN).

• Ipsilesional flash of light and the color blue may worsen ipsilesional spatial bias in stroke survivors with UN.

• Color
• lateralized lights
• stroke
• unilateral neglect

Declaration of interest

No commercial party having a direct financial interest in the results of the research supported this article neither has nor will confer a benefit on the authors or on any organization with which the authors are associated. The study was partly funded by the Ministry of Science and Technology (MOST-94-2314-B-182-027; MOST-102-2811-B-002-081) in Taiwan. The authors declare no conflicts of interests.