Visual sensitivity and cortical response to the temporal envelope of amplitude-modulated flicker.
To investigate the perception of a temporal envelope of flickering light is important for understanding nonlinear temporal processing in the visual system. The influence of the frequency components of a flickering light on the perception of the envelope remains unclear, with few studies having investigated the cortical activities for the envelope. We investigated the detection thresholds, brightness, and magnetoencephalographic responses related to amplitude-modulated (AM) flickering lights. The results showed that the sensitivity to flicker at the envelope periodicity of the AM flickering light was lower for a high-frequency carrier (40 Hz) than for a lower-frequency one (10, 20, or 30 Hz). Also, the primary visual cortex responded at the frequency corresponding to the envelope periodicity of the AM flickering light, and the strength of the cortical response reflected the brightness of the flicker at the envelope periodicity.
Okamoto
Yosuke
Y
Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan. yos-okamoto@aist.go.jp
Nakagawa
Seiji
S
Fujii
Kenji
K
Yano
Takashi
T
D000328:Adult; D005260:Female; D006801:Humans; D008027:Light; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D010775:Photic Stimulation; D010783:Photometry; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D012984:Software; D013997:Time Factors; D014785:Vision, Ocular; D014796:Visual Perception