There has been some controversy regarding the susceptibility of ocular dominance column width to environmental influences. Löwel (1994) and Roe et al. (1995) had claimed that ocular dominance column width is affected by abnormal visual experiences such as strabismus or amblyopia. Horton and Hocking (1996) subsequently placed these claims into question by demonstrating that there is significant normal variability in the width of ocular dominance columns, both across individuals and with respect to eccentricity. Assessing this variability has proven difficultbecause a standard means of quantifying ocular dominance column width is not available (cf. Kaschube et al., 2001). Here, a mathematically-justified, standardized method of calculating mean ocular dominance column width for optical images of primary visual cortex was formulated. The utility of this method was tested by comparing results obtained through its use with those acquired by alternate methods and by applying it to previously published maps. Mean ocular dominance column width was quantified for a large body of optical images from normal adults of three species of macaque monkey, Macaca fascicularis, Macaca mulatta, and Macaca nemestrina, and two visual eccentricity groups, 1° to 3° and 5° to 10°. Cross-species and eccentricity comparisons made from these results were used to determine the variability of ocular dominance column width measurements. Results from this study provide a benchmark by which to compare other sets of ocular dominance column width data, including those from other species, from normal developmental studies, and from studies on abnormal visual development. The successful implementation of this novel technique suggests that it may be suited for future use in additional studies.
ASJC Scopus subject areas
- Sensory Systems