Abstract
Critical flicker fusion threshold (CFFT) is the lowest level of continuous flicker that is perceived as a steady source of light and has historically been shown to be remarkably stable within and across multiple days of testing. The current study was designed to test the relationship between CFFT and subliminal learning. Seven participants were exposed to sub-threshold coherent dot motion occurring as a background feature of a rapid serial visual presentation task, with twenty-eight additional subjects serving as controls. A subset of the experimental participants was retested one year after their initial exposure. Neural plasticity was instigated and measured with a Dynamic Random-Dot Display computer program, and a Macular Pigment Densitometer was used to measure CFFT. Herein, we demonstrate that subjects who underwent one hour of subliminal motion training per day for nine days experienced a significant increase in CFFTs (an average of 30%). Subjects who completed tasks without the motion-pairing showed no significant improvement. Subjects who were retested after one year showed sustained CFFT increases. These results indicate that: 1) A unique visual experience can dramatically alter one's CFFT; 2) CFFT may be highly related to dorsal stream motion processing; and 3) Increases in CFFT can be maintained long-term.