Bresar, M.Martindale, W. S.Miers, C. Robert2010-04-282010-04-2819912010-04-28http://hdl.handle.net/1828/2661Let R be a prime ring with involution, of characteristic \ne 2, with center Z, skew elements K, and extended centroid C. Theorem. Suppose [K,K] \ne {0} and f:K->K is an additive map such that [f(x),x] \in Z for all x \in K. Then, unless R is an order in a 16-dimensional central simple algebra, there exists \lambda \in C and an additive map \mu: K -> C such that f(x)=\lambda x + \mu(x) for all x \in K.entechnical reports (mathematics and statistics)Technical ReportDepartment of Mathematics and Statistics