He closed his eyes and visualised himself standing on the podium.

visualised 是动词 visualise 的过去式，visualise 由词根 visual（视觉的）加上后缀 -ise（使...化）构成，意思是"在脑海中形成视觉形象"，即"想象、可视化"。在美式英语中拼写为 visualized。