Asymmetrical Discrimination in Visuospatial Information at the Preconscious Stage

Abstract

[Purpose] Cerebral responses discriminating information at the preconscious stage of visuospatial information were investigated using magneto-encephalography to clarify their characteristics. [Subjects] The subjects were 10 healthy right-handed adults with visual acuity ≥0.8 who had no history of nervous or mental disease. [Methods] Using apparent movement, the mismatch field (MMF) of repeated stimulus in the same direction and deviant stimulus in the opposite direction was measured, and the inferred current intensities of the MMF generated by stimuli in the up, down, left, and right directions were compared. [Results] The inferred MMF currents generated in the right hemisphere by leftward standard stimulus and rightward deviant stimulus were significantly large. [Conclusion] The results suggest greater brain activity is generated in the detection of rightward deviant stimulus, indicating a directional characteristic exists in the visuospatial perception function, and the relationship of this visuospatial perception function with the fall risk of the elderly should be investigated.