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Synesthesia

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Synesthesia is a remarkable condition where stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway. People with synesthesia experience a blending or crossing of their senses, such as sight and sound, leading to cross-modal sensations. In this condition, the stimulation of one sense, such as hearing a number or musical note, triggers an experience of another sense, like sensing a specific color, taste, or smell. People...

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Related Experiment Video

Updated: May 23, 2026

Training Synesthetic Letter-color Associations by Reading in Color

Training Synesthetic Letter-color Associations by Reading in Color

Published on: February 20, 2014

Synaesthesia and colour constancy.

Holly Erskine¹, Jason B Mattingley, Derek H Arnold

¹School of Psychology, The University of Queensland, Australia.

Cortex; a Journal Devoted to the Study of the Nervous System and Behavior

|April 11, 2012

Summary

This summary is machine-generated.

Grapheme-colour synaesthesia involves seeing colours with text. This study found synaesthetic colours are processed at higher brain levels, unaffected by lighting changes, unlike normal colour perception.

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Area of Science:

Neuroscience
Cognitive Psychology
Sensory Perception

Background:

Grapheme-colour synaesthesia is a condition where individuals perceive colours associated with achromatic text.
Colour perception in typical individuals is influenced by lighting conditions, a phenomenon known as colour constancy.
The neural basis of synaesthetic colour perception remains incompletely understood.

Purpose of the Study:

To investigate the level of colour processing involved in grapheme-colour synaesthesia.
To determine if synaesthetic colour experiences are susceptible to colour constancy mechanisms.
To differentiate the neural locus of synaesthetic colour generation from that of normal colour perception.

Main Methods:

Utilized colour matching and naming tasks to assess synaesthetic colour perception.
Introduced simulated coloured illuminants to test for interactions with synaesthetic colours.
Compared synaesthetic colour responses to control participants performing colour matching on physically coloured stimuli.

Main Results:

Synaesthetic colour matching and naming were not affected by simulated changes in illuminant colour.
Control participants' colour matching performance was influenced by the simulated coloured illuminants, demonstrating colour constancy.
The results indicate a dissociation between synaesthetic colour processing and the mechanisms underlying perceptual constancy.

Conclusions:

Synaesthetic colour experiences are likely generated at higher levels of visual processing.
These higher-level colour signals are not subject to the same constancy adjustments as colours perceived through lower-level visual pathways.
The findings suggest a distinct neural pathway for synaesthetic colour perception, separate from the mechanisms supporting normal colour constancy.