"The sequencing of the pictures on these trials was randomly determined by a randomizing algorithm … and their left/right target positions were determined by an

"The sequencing of the pictures on these trials was randomly determined by a randomizing algorithm … and their left/right target positions were determined by an Araneus Alea I hardware-based random number generator." http://www.araneus.fi/products-alea-eng.html http://www.araneus.fi/products-alea-eng.html