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1888 Amer. Jrnl. Psychol. 2 639 Let us see if, as Helmholtz says, we have to do with contrast effects only... The shadow will appear of a slightly red tinge... This red is evidently purely an effect of contrast with the green.

1905 W. James in McClure's Mag. May 5/2 Thoroughness of sympathy..made us overflow, on meeting after long absences, into such laughing greetings as: ‘Ha! you old thief! Ha! you old blackguard!’—pure ‘contrast-effects’ of affection and familiarity passing beyond their bounds.

1909 E. B. Titchener Text-bk. Psychol. i. 76 The contrast-effect is always in the direction of greatest opposition.

1966 L. M. Hurvich & D. A. Jameson Perception of Brightness & Darkness v. 96 If we want a vividly striking demonstration of contrast effects, we can set up a stimulus situation where contours or lines are perceived in the visual field by contrast action even though no such lines actually exist in the stimulus pattern itself.

1967 H. Helson et al. Contemp. Approaches Psychol. iv. 165/2 The contrast effects (elation and depression) implied a learning about reward with which the older theory certainly could make no contact.