Synesthesia and the McCollough Effect

Synesthesia and the McCollough Effect

Synesthetes, who see printed black letters and numbers as being colored, are thought to have enhanced cross-activation between brain modules for color and form. Since the McCollough effect also results from oriented contours (i.e., form) evoking specific colors, we conjectured that synesthetes may experience an enhanced McCollough effect, and find that this is indeed true.

Conditioning and blocking of the McCollough effect.

The cliassical conditioning explanation of the McCollough effect was extended by investigating blocking and allied phenomena predicted by the Rescorla-Wagner (1972) equations. The subjects were first exposed to colored gratings or moving spirals and then were tested after induction with a compound of both types of stimuli. The effects appeared to be additive, and the stronger stimuli overshadow...

The anti-McCollough effect: the mystery remains.

The functional anatomy of the McCollough contingent colour after-effect.

We report two functional magnetic resonance imaging (fMRI) experiments which reveal a cortical network activated when perceiving coloured grids, and experiencing the McCollough effect (ME). Our results show that perception of red-black and green-black grids activate the right fusiform gyrus (area V4) plus the left and right lingual gyri, right striate cortex (V1) and left insula. The ME activat...

Probing unconscious visual processing with the McCollough effect.

The McCollough effect, an orientation-contingent color aftereffect, has been known for over 30 years and, like other aftereffects, has been taken as a means of probing the brain's operations psychophysically. In this paper, we review psychophysical, neuropsychological, and neuroimaging studies of the McCollough effect. Much of the evidence suggests that the McCollough effect depends on neural m...