"Facephenes": Brain Stimulation Creates Phantasmal Faces

Have you ever seen a face on a football? In a new paper, neuroscientists Gerwin Schalk et al. report that brain stimulation caused a man to experience strange hallucinations. The patient saw faces in everyday objects, including an orange soccer ball and a featureless box. The researchers coined the word "facephenes" to refer to these face-like perceptions. Schalk et al. studied a 26 year old Japanese man suffering from intractable epilepsy. The patient was implanted with a large number of brain electrodes in order to pin down the source of his seizures. Crucially for Schalk et al., several of the electrodes lay on the fusiform face area (FFA). The FFA has been a focus of much research to determine whether it is - as the name suggests - a brain area devoted to the perception of faces. While there have been monkey studies previously, Schalk et al. say this is the first human study to focus on the how FFA stimulation affects the perception of non-face objects.