Direct comparison of visual cortex activation in human and non-human primates using functional magnetic resonance imaging

We report a technique for functional magnetic resonance imaging (fMRI) in a n awake, co-operative, rhesus macaque (Macaca mulatta) in a conventional 1. 5T clinical MR scanner, thus accomplishing the first direct comparison of a ctivation in visual cortex between humans and non-human primates with fMRI. Activation was seen in multiple areas of striate and extra-striate visual cortex and in areas for motion, object and face recognition in the monkey a nd in homologous visual areas in a human volunteer. This article describes T-1, T-2 and T-2* values for macaque cortex, suitable MR imaging sequences, a training schedule, stimulus delivery apparatus and restraining hardware for monkey fMRI using a conventional 19 cm knee coil. Much of our understan ding of the functional organization of the primate brain comes from physiol ogical studies in monkeys. Direct comparison between species using fMRI suc h as those described here will help us to relate the wealth of existing kno wledge on the functional organization of the non-human primate brain to hum an fMRI. (C) 2001 Elsevier Science B.V. All rights reserved.