Abstract

The responses of macaque monkey lateral geniculate neurons to full-field temporal achromatic flicker and drifting sine-wave gratings (mean luminance 17 cd/m²) were studied using single-unit recording methods. Cells were also classified into spectrally opponent or broadband on the basis of their responses to diffuse narrowband spectral luminance increments, using principal-component analysis¹ and cross-point techniques. The results showed that the mean peak temporal frequency response of broadband cells (10.8 ± 3.2 Hz, n = 12) was significantly greater than that of opponent cells (4.0 ± 0.3 Hz, n = 36) regardless of stimulus modulation level, electrode depth, or whether a cell was the on-or off-center type. Also, the mean response amplitude to the optimum temporal frequency stimulus was significantly larger for broadband cells than opponent cells, again for all conditions tested. Finally, broadband cells responded to lower spatial frequencies of drifting gratings than did opponent cells at all stimulus modulations (e.g., 1.1 ± 0.1 cycles/deg, n = 14 for broadband cells; 1.9 ± 0.2 cycles/deg, n = 45 for opponent cells, 95% stimulus modulation). These spatiotemporal differences between opponent and broadband cell groups in the monkey LGN are consistent with differences between opponent and broadband chromatic channels as inferred from human psychophysical studies.

© 1987 Optical Society of America