Synaesthesia is a condition in which one type of stimulation evokes the sensation of another, as when the hearing of a sound produces photisms, i.e. mental percepts of colours. R is a 20 year old colour blind subject who, in addition to the relatively common grapheme-colour synaesthesia, presents a rarely reported cross modal perception in which a variety of visual stimuli elicit aura-like percepts of colour. In R, photisms seem to be closely related to the affective valence of stimuli and (...) typically bring out a consistent pattern of emotional responses. The present case study suggests that colours might be an intrinsic category of the human brain. We developed an empirical methodology that allowed us to study the subject's otherwise inaccessible phenomenological experience. First, we found that R shows a Stroop effect (delayed response due to interference) elicited by photisms despite the fact that he does not show a regular Stroop with real colours. Secondly, by manipulating the colour context we confirmed that colours can alter R's emotional evaluation of the stimuli. Furthermore, we demonstrated that R's auras may actually lead to a partially inverted emotional spectrum where certain stimuli bring out emotional reactions opposite to the normal ones. These findings can only be accounted for by considering R's subjective colour experience or qualia. Therefore the present paper defends the view that qualia are a useful scientific concept that can be approached and studied by experimental methods. (shrink)

Synaesthesia is a condition in which one type of stimulation evokes the sensation of another, as when the hearing of a sound produces photisms, i.e. mental percepts of colours. R is a 20 year old colour blind subject who, in addition to the relatively common grapheme-colour synaesthesia, presents a rarely reported cross modal perception in which a variety of visual stimuli elicit aura-like percepts of colour. In R, photisms seem to be closely related to the affective valence of stimuli and (...) typically bring out a consistent pattern of emotional responses. The present case study suggests that colours might be an intrinsic category of the human brain. We developed an empirical methodology that allowed us to study the subject's otherwise inaccessible phenomenological experience. First, we found that R shows a Stroop effect elicited by photisms despite the fact that he does not show a regular Stroop with real colours. Secondly, by manipulating the colour context we confirmed that colours can alter R's emotional evaluation of the stimuli. Furthermore, we demonstrated that R's auras may actually lead to a partially inverted emotional spectrum where certain stimuli bring out emotional reactions opposite to the normal ones. These findings can only be accounted for by considering R's subjective colour experience or qualia. Therefore the present paper defends the view that qualia are a useful scientific concept that can be approached and studied by experimental methods. (shrink)

A hypnotic induction produces different patterns of spontaneous experiences across individuals. The magnitude and characteristics of these responses covary moderately with hypnotic suggestibility, but also differ within levels of hypnotic suggestibility. This study sought to identify discrete phenomenological profiles in response to a hypnotic induction and assess whether experiential variability among highly suggestible individuals matches the phenomenological profiles predicted by dissociative typological models of high hypnotic suggestibility. Phenomenological state scores indexed in reference to a resting epoch during hypnosis were submitted (...) to a latent profile analysis. The profiles in the derived four-class solution differed in multiple experiential dimensions and hypnotic suggestibility. Highly suggestible individuals were distributed across two classes that exhibited response patterns suggesting an inward attention subtype and a dissociative subtype. These results provide support for dissociative typological models of high hypnotic suggestibility and indicate that highly suggestible individuals do not display a uniform response to a hypnotic induction. (shrink)

Although the condition known as synaesthesia is currently undergoing a scientific resurgence, to date the literature has largely focused on the heterogeneous nature of synaesthesia across individuals. In order to provide a better understanding of synaesthesia, however, general characteristics need to be investigated. Synaesthetic experiences are often described as occurring ‘internally’ or in the ‘mind’s eye’, which is remarkably similar to how we would describe our experience of visual mental imagery. We assessed the role of visual imagery in synaesthesia by (...) sampling a large group of synaesthetes and found that they report experiencing more vivid mental images than controls. These findings have important implications for our general understanding of synaesthesia and, in particular, emphasize the need to control for visual imagery in behavioural and neuroimaging paradigms. (shrink)

Synaesthesia is considered a rare perceptual capacity, and one that is not capable of cultivation. However, meditators report the experience quite commonly, and in questionnaire surveys, respondents claimed to experience synaesthesia in 35% of meditation retreatants, in 63% of a group of regular meditators, and in 86% of advanced teachers. These rates were significantly higher than in nonmeditator controls, and displayed significant correlations with measures of amount of meditation experience. A review of ancient texts found reports suggestive of synaesthesia in (...) advanced meditators from India and China. These findings suggest that synaesthesia may be cultivated by meditation, and that laboratory studies of meditators could be rewarding. (shrink)