Experienced meditators often report spontaneous visual imagery during deep meditation in the form of lights or other types of visual images. These experiences are usually interpreted as an "encounters with light" and gain mystical meaning. Contrary to the well-studied intentional and controlled visual imagery, spontaneous imagery is poorly understood, yet it plays an important role in...
Synaesthesia is a condition in which one property of a stimulus induces a conscious experience of an additional attribute. For example, in grapheme-colour synaesthesia, a visually presented grapheme results in synaesthetic experiences of colour. These experiences occur in approximately 4% of the population (Simner et al., 2006) and the authenticity of the condition is well established (Cohen...