Identification of tachistoscopically exposed symmetrical and asymmetrical letter arrays

Six-letter arrays containing symmetrical, e.g., H, M, T, or asymmetrical letters, e.g., J, K, R, were tachistoscopically exposed bilaterally for 100 msec. to 100 college students. Significantly more asymmetrical than symmetrical letters were identified, and significantly more Ss identified more asymmetrical than symmetrical items. This experiment, which incorporated methodological considerations suggested by Harcum (1964) and Bryden (1968), corroborates their findings. Their ideas and other findings were used to account for the data. Asymmetrical letters have more intrinsic left-to-right directionality than symmetrical elements. The rapidly fading after-stimulation of tachistoscopically presented alphabetical material is usually scanned from left to right. Individual array letters might also be scanned in the same direction. Confluence of directionality of letter and scan, which obtains only with asymmetrical letters, might have typically allowed asymmetrical targets to be scanned more rapidly and, consequently, more efficiently than symmetrical displays.