BRAIN RESEARCH 271 REPRESENTATION OF CENTRAL VISUAL FIELDS IN PRESTRIATE CORTEX OF MONKEY S. M. ZEKI* National Center for Prevention and Control of Alcoholism, National Institute of Mental Health at St. Elizabeths Hospital, Washington, D.C. (U.S.A.) (Accepted January 7th, 1969) INTRODUCTION In 1941, Talbot and Marshall 16 reported the manner in which the visual fields are represented in striate cortex of monkey. From this study, later confirmed by Daniel and Whitteridge 6, it appeared that the vertical meridian of the lower and upper visual fields is represented at the striate prestriate boundary behind the lunate and above the inferior occipital sulci respectively with the foveal representation occupying a circular area below the tip of the lunate sulcus and the representation of the hori- zontal meridian extending backwards from the 'foveal cortex' (see Fig. 10). Since that time the projections of the striate cortex have been studied by Myers lz and by Kuypers et al. 9. Although in both studies the Nauta staining technique was used, the results obtained are not strictly in accord 19. The many disagreements over the anat- omy, extent and functions of the prestriate cortex in the monkey have been reviewed at length elsewhere 19. Here it is sufficient to point out that the disagreements have not only been interdisciplinary but also intradisciplinary. For example, among students of cytoarchitectonics, Lashley and Clark 10 and, to a lesser extent, yon Bonin and Bailey 1 were not able to confirm the subdivision into the areas 18 and 19 proposed by Brodmann ~. Lashley and Clark concluded from their architectonic work that the areas 18 and 19 of Brodmann 3 could not be told apart and that, together with the area 7, they should be considered a single functional area. Von Bonin and Bailey 1 conceded that differences in cytoarchitecture may exist but disagreed with Brodmann 3 on the distinguishing cytoarchitectonic criteria and also found the differences to be too gradual and too 'subtle' to justify subdivision into 2 distinct fields. And although they did propose a subdivision into the 2 fields OA and OB, they were unable to clearly specify the boundary between these 2 fields or the anterior boundary of OA, the authors not being able to find any striking cytoarchitectonic differences posterior to the temporal pole. * Visiting Associate: present address: Department of Anatomy, University of Wisconsin, Madison~ Wisc. 53706, U.S.A. Brain Research, 14 (1969) 271-291