Sharing the load: How a personally coloured calculator for grapheme-colour synaesthetes can reduce processing costs.

Synaesthesia refers to a diverse group of perceptions. These unusual perceptions are defined by the experience of concurrents; these are conscious experiences that are catalysed by attention to some normally unrelated stimulus, the inducer. In grapheme-colour synaesthesia numbers, letters, and words can all cause colour concurrents, and these are independent of the actual colour with which the graphemes are displayed.

Substantiating synesthesia: a novel aid in a case of grapheme-colour synesthesia and concomitant dyscalculia.

Here we present the case of SP, a 21-year-old female with life-long dyscalculia. SP was subsequently diagnosed with grapheme-color synesthesia, a diagnosis that serendipitously catalyzed our development of a novel aid:The digit-color calculator (DCC). The DCC substantiates SP's color , dramatically ameliorating her difficulties with basic calculations.

Synesthetes show normal sound-induced flash fission and fusion illusions.

Idiopathic synesthesia, a neurological condition in which a stimulus in one sense generates a concurrent experience in a different sense, is often considered an example of multisensory integration. Consequently it has been suggested that synesthetes should experience multisensory illusions more consistently and compellingly than typical participants. To test this we measured the sound induced flash fission and fusion illusions in 22 coloured hearing synesthetes and 31 control participants.