Neural basis of photo/chromatic sensitivity in adolescence.
OBJECTIVE
To determine a psychophysiological basis for age visual sensitivity to chromatic and achromatic stimuli.


METHODS
We investigated the effects of achromatic and four isoluminant color combinations (blue/red, blue/green, green/red, and blue/yellow), luminance ratio changes in color combinations (blue/red; 1:1, 3:4, 4:3) and contrast changes (3 to 100%) on steady-state electroretinograms (ERGs) and visual evoked potentials (VEPs) in 32 healthy teenagers and 30 young adults.


RESULTS
We found that (1) dual peaks at 9 and 18 Hz with a dip at 12 Hz were observed in VEPs with all isoluminant color combinations, (2) VEP responses were significantly enhanced and the 12-Hz dip became unclear with luminance ratio changes between two colors with a nonantagonistic relationship (blue/red), and (3) VEP amplitudes were significantly increased when the contrast was increased. These characteristics were more evident in teenagers than young adults; however, ERGs were qualitatively similar between the two groups.


CONCLUSIONS
The visual cortex is differently modulated by different color-luminance combinations, and higher sensitivity to color-luminance combinations in the visual cortex in teenagers is responsible for the high prevalence of photo/chromatic sensitivity in adolescence.
Yamasaki
Takao
T
Department of Clinical Neurophysiology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. yamasa@neurophy.med.kyushuu.ac.jp
Goto
Yoshinobu
Y
Kinukawa
Naoko
N
Tobimatsu
Shozo
S
D000293:Adolescent; D000328:Adult; D002648:Child; D003118:Color Perception; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010812:Physical Stimulation / Q000379:methods*; D012160:Retina / Q000502:physiology*; D014793:Visual Cortex / Q000503:physiopathology*