 A well-known experiment asks subjects to attend to the number of passes of a ball thrown by players in white shirts while ignoring a second ball passed by players in black shirts (Simons &amp; Chabris 1999). During the task, a person in a gorilla costume walks across the scene. Half of the subjects fail to notice and report the gorilla, this being construed as evidence for the absence of visual awareness of the gorilla. Hence, failure to attend to the gorilla is said to render subjects phenomenally blind to it. Similar claims are made in change blindness where subjects fail to detect the difference between two similar pictures (Simons &amp; Ambinder 2005), the attentional blink where subjects fail to detect a stimulus presented immediately after detecting a prior stimulus (Dux &amp; Marois 2009; Martens &amp; Wyble 2010), and hemispatial neglect where patients fail to report objects in a part of their visual field that they cannot attend to due to brain lesions.