Why color synesthesia involves more than color.
Synesthesia is a perceptual phenomenon in which stimuli can trigger experiences in non-stimulated sensory dimensions. The literature has focused on forms of synesthesia in which stimuli (e.g. music, touch or numbers) trigger experiences of color. Generally missing, however, is the observation that synesthetic colors are often accompanied by the experience of other surface properties such as texture (e.g. a visual experience of linen, metal, marble, velvet, etc). Current frameworks for synesthesia focus only upon the involvement of brain regions such as the V4 color complex. Here, we propose an expanded framework that includes brain regions involved in the encoding of material properties - specifically, larger regions of the medial ventral stream. The overlap of visual texture and color processing within ventral regions might explain why many experiences of synesthesia extend beyond color to other material properties.
Eagleman
David M
DM
Departments of Neuroscience and Department of Psychiatry, Baylor College of Medicine, Houston, TX 77030, USA. eagleman@bcm.edu
Goodale
Melvyn A
MA
D001921:Brain / Q000502:physiology*; D003116:Color; D003118:Color Perception / Q000502:physiology*; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D014795:Visual Pathways / Q000502:physiology