For my COGS 310: Consciousness project, I’ve been researching synethesia. Synethesia is the experience of a sense cross-modally. A synesthete may perceive time in a spatial rather than numeric terms. This particular article I’ve been reading is about an individual, R, who perceives his personal emotional states with colour. I drew up some of the juicier details of the study:

Subject R

R is a colour-blind synaesthete. Visually, he has trouble discriminating between between certain shades of red, brown, and green. R’s sensation of colour is, seemingly, a quale.¹ The paper discusses this aspect of R’s perception as being an aura or aura photism.

R’s Perception

When R encounters a person or object, he states that he experiences a sensation of colour: one that is never projected externally onto the person being perceived. Like all synaesthetes, R claims that his experience is highly consistent over time and cannot be suppressed by will.

Experiments & Method

The first experiments were establishing the extent of colour perception in R. They involved colour identification tasks and a stroop test. He had a hard time with certain colours and greys (especially red-green discrimination). There was no significant Stroop effect. The next set of experiments were aimed at inspecting the consistency of R’s aura photisms. The authors used the IAPS ² and went through approximately 500 images, naming an aura for each one. His responses were 98% consistent over time when he repeated the test 30 days later. The final set of pilot experiments involved the colours of emotion. Some of the stimuli that R described as perceiving a green photism included: tarantula spider, mutilated human head, mutilated dead body, half naked man with badly burnt body. It would seem that R’s green photisms were evoked with emotionally negative pictures. Red photisms tended to be evoked with emotionally positive pictures.

The Aura Stroop Effect

(This is the cool part) Although R performed well on the classical Stroop test (most likely due to his colour-blindness) he exhibited an Aura Stroop triggered by imaginary colours. These experiments involved an IAPS stimulus, followed by a colour stimulus. R had difficulty discriminating his aura photism from the colour-stimulus.

If you’re interested you should check it out. Here’s a full citation:

Hochel, M. Milan, E., Gonzalez, A., Tornay, F., McKenney, K., Diaz Caviedes, R., et al. (2007). Experimental Study of Phantom Colours in a Colour Blind Synaesthete. Journal of Consciousness Studies, 14, 75-95.