Direct current visual evoked potentials on light and dark adaptation process.

Research Project

Project/Area Number	61510031
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Psychology
Research Institution	University of Tsukuba
Principal Investigator	YOSHIDA Shigeru University of Tsukuba, Institute of Health and Sports Sciences, Assistant Professor., 体育科学系, 講師 (40133045)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥2,600,000 (Direct Cost: ¥2,600,000) Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1986: ¥2,300,000 (Direct Cost: ¥2,300,000)
Keywords	Visual evoked potential / Direct current amplification / Luminance / 短期順応 / 明るさ知覚 / 順応水準 / 視覚野脳波 / 直流成分 / サチレーション / EASY
Research Abstract	Visual evoked potentials(VEP) were recorded by direct current amplification from Occipital to investigate the short term light and dark adaptation process. Stimulus patterns were light and dark step functions with the duration of 10, 50, 100, 500, 1000ms, and light and dark flash trains with 5, 10 and 20Hz. Averaged DC VEP and AC VEP(time constant 0.3s) were computed from 50 raw data. Adaptational shifts of DC VEP were found corresponding to light and dark stimulations: upward shift(negative) was for light adaptation and downward shift(positive) was for dark adaptation. Simulation of train VEP with adaptation factor was fitted better than without adaptation factor. A VEP model was proposed including onset, offset, adaptation, contrast and delay factors. Some of computer programs for experiment, EASY(EEG Analysis SYstem), were introduced to researchers of experimental psychology.