High Resolution Tractography in Macaque Visual System Validation Against in Vivo Tracing

Laura M. Parkes^1,2, Hamied A. Haroon^1,2, Mark Augarth³, Nikos K. Logothetis, ^2,3, Geoff JM Parker^1,2

The aim is to validate the connections identified with high angular resolution diffusion imaging in the post-mortem macaque visual system against true connections from the many detailed in vivo tracer studies. A probabilistic tractography approach is used, and comparisons are made between identified connections at different thresholds of connection strength, and the true connections. The accuracy of connections increases up until an acceptance threshold of 5%, beyond which accuracy is not greatly affected. 72% of connections were correctly identified at 5% threshold. The majority of false connections involved areas of higher level processing, particularly parietal and temporal regions.