Infant temporal contrast sensitivity functions (tCSFs) mature earlier for luminance than for chromatic stimuli: evidence for precocious magnocellular development?

Abstract

In order to investigate the development of luminance and chromatic temporal contrast sensitivity functions (tCSFs), we obtained chromatic and luminance contrast thresholds from individual 3- and 4-month old infants, and compared them to previously obtained functions in adults. Stimuli were moving sinusoidal gratings of 0.27 cyc/deg, presented at one of five temporal frequencies: 1.0, 2.1, 4.2, 9.4 or 19 Hz (corresponding speeds: 3.8, 7.7, 15, 34, 69 deg/s). Previous studies, including our own, have shown that adult tCSFs are bandpass for luminance stimuli (peaking at 5-10 Hz), yet lowpass for chromatic stimuli (sensitivity falling at > 2 Hz), and that the two functions cross one another near 4-5 Hz when plotted in terms of cone contrast. In the present study, we find that the shapes and peaks of the luminance tCSF in both 3- and 4-months-olds appear quite similar to those of adults. By contrast, chromatic tCSFs in infants are markedly different from those of adults. In agreement with our earlier report (Dobkins, K. R., Lia, B., & Teller, D. Y. (1997). Vision Research, 37(19), 2699-2716), the chromatic function in 3-month-olds is rather flat, lacking the sharp high temporal frequency fall-off characteristic of the adult function. In addition, the luminance tCSF in 3-month-olds is elevated above the chromatic tCSF, and the two functions do not exhibit an adult-like cross-over within the range of temporal frequencies tested. By 4 months of age, substantial development of chromatic contrast sensitivity takes place at the lowest temporal frequencies. Although still immature, the 4-month-old chromatic tCSF has begun to adopt a more adult-like shape. In addition, similar to adults, luminance and chromatic tCSFs in 4-month-olds cross one another near 5 Hz. In adults, magnocellular (M) and parvocellular (P) pathways are thought to underlie the bandpass luminance and lowpass chromatic tCSF, respectively (e.g. Lee, B. B., Pokorny, J., Smith, V. C., Martin, P. R., & Valberg, A. (1990). Journal of the Optical Society of America (a), 7(12), 2223-2236). Based on this correspondence between psychophysical and neural responses in adults, our results suggest that the relatively slow development of the chromatic tCSF in infants may reflect immature chromatic responses in the P pathway and/or reliance on chromatic responses originating in the M pathway.

Spatial Contrast Sensitivity in Adolescents with Autism Spectrum Disorders

“…The log contrast sensitivities derived for the seven different spatial frequencies were fitted with a double exponential function to create a contrast sensitivity function (CSF), using an iterative minimization process as previously described (Dobkins, Anderson, & Lia, 1999;Movshon & Kiorpes, 1988). The function is described as:…”

Development of Temporal Response Properties and Contrast Sensitivity of V1 and V2 Neurons in Macaque Monkeys

“…Human infants also have poor sensitivity to temporally modulating stimuli during the first 8 mo of life (roughly equivalent to 8 wk of age in monkeys) (e.g., Dobkins et al 1999;Rasengane et al 1997;Swanson and Birch 1991;but see Regal 1981). Normal maturation of "higher-order" temporal vision (e.g., motion integration) is relatively delayed and continues for Ն3 yr, although this ability was reported to be present around 2 mo of age in humans (Dobkins et al 2004).…”

Development of sensitivity to visual motion in macaque monkeys

“…Regal (1981) reported adult-level critical flicker fusion frequency (CFF) in 2-month-old infants (but see also, Rasengane et al, 1997). However, temporal contrast sensitivity is quite immature below the CFF up to at least 8 months (Swanson & Birch, 1990;Teller et al, 1992;Hartmann & Banks, 1992;Rasengane et al, 1997;Dobkins et al, 1999), though it reaches adult levels relatively early compared to spatial contrast sensitivity (Ellemberg et al, 1999). No data are as yet available on the development of temporal mechanisms in the monkey.…”