The synaesthetic brain displayed a different pattern of activity to words when compared to the non-synaesthetes, with insula activation related to viewing words that elicited tastes that have an associated emotional valence (i.e., pleasant or unpleasant tastes). The subjective intensity of the synaesthesia was correlated with activity in the medial parietal lobes (precuneus/retrosplenial cortex),
which are implicated in polymodal imagery and self-directed thought. This region has also previously been activated in studies of lexical–colour synaesthesia, suggesting its role may not be limited to the type of synaesthesia explored here. Cilomilast mouse “
“Recent research suggests synesthesia as a result of a hypersensitive multimodal binding mechanism. To address the question whether multimodal integration is altered in synesthetes in general, grapheme-colour and auditory-visual synesthetes were investigated using speech-related stimulation in two behavioural experiments. First, we used the McGurk illusion to test the strength and number of illusory perceptions in synesthesia. In a second selleckchem step, we analysed the gain in speech perception coming from seen articulatory movements under acoustically noisy conditions. We
used disyllabic nouns as stimulation and varied signal-to-noise ratio of the auditory stream presented concurrently to a matching video of the speaker. We hypothesized that if synesthesia is due to a general hyperbinding mechanism this group of subjects should be more susceptible
to McGurk illusions and profit more from the visual information during audiovisual speech perception. The results indicate that there are differences between synesthetes and controls concerning multisensory integration – but in the opposite direction as hypothesized. Synesthetes showed a reduced number of illusions and had a reduced gain in comprehension by viewing matching articulatory movements in comparison 上海皓元 to control subjects. Our results indicate that rather than having a hypersensitive binding mechanism, synesthetes show weaker integration of vision and audition. Synesthesia refers to the uncommon ability to perceive an internally generated sensation in one sensory modality triggered by a stimulus coming from another sensory modality. Thus, an external stimulus, in the synesthesia literature often called inducer, leads to an additional percept called concurrent (Grossenbacher & Lovelace, 2001). The type of synesthesia is named according to the inducer–concurrent pair: in auditory-visual synesthesia, for example, acoustic stimulation leads to a visual experience, whereas in linguistic-colour synesthesia speech-related stimuli lead to a visual experience. Synesthesia has been estimated to affect about 4% of the population (Simner et al., 2006). The most investigated form of synesthesia is grapheme-colour synesthesia with affected subjects perceiving written and heard letters in different colours (Simner et al., 2006).