2 The Characteristics of Two Negative Peaks on Visual Evoked Potentials with Depth Perception Yoichi MIYAWAKI, Yasuyuki YANAGIDA, Taro MAEDA, and Susumu TACHI Random-Dot Stereogram 200 ms 40 180 ms 280 ms 2 N180 N280 N180 N280 N280 Random-Dot Stereogram 2 1. Random-Dot Stereogram RDS Visual Evoked Potential, VEP [1], [2] RDS 1960 Julesz RDS VEP RDS [3] [8] 200 ms 1 Graduate School of Engineering, The University of Tokyo, Tokyo, 113 8656 Japan CRT Head- Mounted Display HMD HMD [9] VEP [8] 45 45 [10] 40 RDS VEP D II Vol. J82 D II No. 5 pp. 961 972 1999 5 961
99/5 Vol. J82 D II No. 5 2 VEP RDS 2 2. A 2. 1 Static RDS Correlogram, CRG 100 ms 0 RECT 0 3 RECT R3 6 RECT R6 3 RECT L3 6 RECT L6 CRG 6 1 700 ms CRG 600 ms CRG 1 25 1 CRG 1 2 CRG CRG 1400 ms 3 4 100 1 41 31 2.4 27 30 1.2 1.2 40% 2. 2 2. 2. 1 4 2 6 2. 2. 2 2 1m 1m 1 Fig. 1 Presentation of the stereo-rectangle stimuli (RECT). Fig. 2 2 Schematic of the experimental system. 1.6 m SHARP 962
2 XV-E500 41 cd/m 2 2. 2. 3 10 20 19 ch 1ch 7 20 kω MME- 3132 5 µv/v 0.53 100 Hz A/D 1 khz 100 IBM PC/AT 1 2. 3 3 RECT 0 CRG 3 O1, O2 2 3 RECT 0 CRG 4 2 RECT 0, RECT R3, CRG O1, O2 1 1000 ms O1, O2 180 ms 280 ms 1 N180 2 N280 N180 CRG N280 CRG 3 Fig. 3Examples of the topographies for stereo-rectangle (RECT 0) and correlogram (CRG). 2 963
99/5 Vol. J82 D II No. 5 N180 N280 A VEP VEP B, C (a) 3. B A VEP B C RDS B RDS VEP A VEP 3. 1 A 5 5 [13], [14] Fig. 4 (b) 4 Examples of the VEPs for stereo-rectangles with lateral shifts. 5 Fig. 5 Geometry of the occluding contours and the binocular unpaired regions. 964
2 Fig. 6 6 RDS RDS patterns for the unpaired region stimuli. Fig. 7 7 Presentation of the unpaired region stimuli (UNP). A 6 6 AAA CCC A1 AAA CCC Unpaired AAA CCC Illusory Occluder BBB RDS BBB CCC A 5 A 7 7 UNP 0 0 UNP R3, UNP R6, UNP L3, UNP L6 3 6 3 6 3. 2 A 2 1 3 3. 3 8 A 2 0 RECT 0 UNP 0 CRG O1, O2 8 UNP 0 RECT 0 2 1 2 CRG 2 N280 10 80 ms 2 N280 5. 3 965
99/5 Vol. J82 D II No. 5 (a) Fig. 9 9 2 Latency of the two peaks for stereo-rectangles and unpaired region stimuli. (b) 8 Fig. 8 Examples of the VEPs for stereo-rectangles and unpaired region stimuli. N180 N280 RECT UNP 9 9 N180 N280 N180 N280 9 16 A N180 N280 4. C B 4. 1 10 30 Wide 966
2 Table 1 1 Characteristics of each stimulus. arcmin RECT 0 30 UNP 0 0 SRG 30 UCG 0, 12, 30 CRG 0 Fig. 10 10 Schematic of the wide stereogram (SRG) and uncorrelogram (UCG). (a) Fig. 11 11 Presentaion of the wide stereogram (SRG) and uncorrelogram (UCG). (b) Stereogram, SRG 0, 12,30 Uncorrelogram, UCG RECT 0 CRG A, B 11 1 C B UNP 0 4. 2 A 1 12 Fig. 12 Examples of the VEPs for wide stereogram and uncorrelogram. 1 2 4. 3 12 A, B 2 O1, O2 12 A, B 2 1 N180 967
99/5 Vol. J82 D II No. 5 CRG 2 N280 RECT 0, SRG, CRG UCG CRG SRG RECT 0 N180 N280 13 1 13 N280 CRG SRG CRG SRG RECT 0 UCG RECT 0, SRG, CRG RECT 0 SRG CRG 132 Fig. 13Average amplitude and variance of N180 and N280 for each stimulus. UCG UCG B UNP 0 3. UNP 0 N280 UCG N180 N280 N280 N180 5. 5. 1 N180 N280 N180 N280 N180 N280 C SRG RECT 0 SRG 30 RECT 0 SRG RECT 0 SRG 968
2 V4 O1, O2 Pz 150 200 ms O1, O2 O1, O2 O1, O2 V1 N280 O1, O2 2 RDS 1 HMD [9] 2 1 Lehmann VEP [15] 2 5. 2 2 2 N280 CRG 14 CRG Fig. 14 Examples of the VEPs for the stereo-rectangle stimulus subtracted CRG response. 15 CRG Fig. 15 Examples of the VEPs for the unpaired region stimulus subtracted CRG response. 969
99/5 Vol. J82 D II No. 5 14 15 RECT 0 UNP 0 14 15 N180 N280 0 N280 5. 3 O1, O2 N280 16 0 16 [3] V1 O1, O2 RECT 0 UNP 0 RECT 0 UNP 0 R3, L3 RECT 0 UNP 0 N280 RECT 0 VEP 6. 16 N280 Fig. 16 Dependency of amplitude on the location of rectangle area. 40 RDS VEP 180 ms 280 ms 2 N180, N280 N180 N280 N180 N280 CRG N180 970
2 N280 VEP 2 2 [1] VEP 11 pp.429 432, 1996. [2] MBE96-126, vol.96, no.581, 1997. [3] vol.98, no.3, pp.298 305, 1994. [4] vol.89, no.3, pp.470 475, 1985. [5] Static random-dot stereogram VEP vol.89, no.4, pp.582 588, 1985. [6] VEP vol.89, no.9, pp.1059 1063, 1985. [7] random dot stereogram VEP vol.96, no.8, pp.985 992, 1992. [8] B. Julesz, W. Kropff, and B. Petrig, Large evoked potentials to dynamic random-dot correlograms and stereograms permit quick determination of stereopsis, Proc. Natl. Acad. Sci. USA, vol.77, no.4, pp.2348 2351, 1980. [9] vol.10, no.5, pp.655 665, 1992. [10] 10 IV 1, O plus E, no.122, pp.168 174, 1990. [11] VEP, Mook, vol.14, pp.182 189, 1980. [12] 1995. [13] K. Nakayama and S. Shimojo, Da Vinci stereopsis:depth and subjective occluding contours from unpaired image points, Vision Res., vol.30, pp.1811 1825, 1990. [14] L. Liu, S.B. Stevenson, and C.M. Schor, Quantitative stereoscopic depth without binocular correspondence, Nature, vol.367, no.6, pp.66 69, 1994. [15] D. Lehmann, H.P. Meles, and Z. Mir, Average multichannel EEG potential fields evoked from upper and lower hemi-retina: latency differences, Electroenceph. Clin. Neurophysiol., vol.43, no.5, pp.725 731, 1977. 10 5 18 11 18 8 10 63 2 9 10 62 4 6 9 2 9 3 IEEE 971
99/5 Vol. J82 D II No. 5 43 48 50 MIT 1 4 6 IEEE/EMBS IMEKO IMEKO SICE 972