Extremely long-term persistence of the McCollough effect.

Abstract

The question has been raised whether an associative mechanism is responsible for the persistence of the McCollough effect. Since current estimates of its rate of decay are derived from procedures in which subjects are repeatedly tested, it was hypothesized that the measured effects might be attenuated by the testing process. Accordingly, a comparison was made between repeated testing and time-elapse testing. A conventional group of 16 subjects had repeated testing at 0, 8, 24, 56, and 120 hr. after induction. Five other groups of 16 were run, each at one of the time delays, with no intervening tests; an additional measure was taken where appropriate at 120 hr. A magenta-green nulling procedure was used to assess the aftereffect. The repeated-test group showed a linear decrease of effect against the stated delays, reaching zero at 120 hr. In contrast, the time-elapse groups showed little decline up to 120 hr. Those groups retested at 120 hr. showed declines due to prior testing. When four more groups were subsequently tested at intervals up to 2,040 hr., the effect remained at better than half strength.

Induction of the McCollough effect I: Figural variables

“…The conditioned stimulus (CS) is the grating that appears with the color. Thus, presentation of magenta leads to greater relative sensitivity to green, and this change in sensitivity becomes linked to the orientation Jones and Holding's (1975) report that testing accelerates the rate of decay. Presumably, eliciting the aftereffect by presenting achromatic gratings acts as extinction trials.…”

Orientation-contingent tactual size aftereffects

“…Adapting a colorcoded orientation detector to a particular color decreases its sensitivity to that color; a properly oriented achromatic test grating then produces a complementary color aftereffect. The most telling criticisms of that neural fatigue model are based on the extremely long duration of the McCollough effect-nearly 3 months under some conditions (Jones & Holding, 1975). Several workers (for example, Mayhew & Anstis, 1972;Murch, 1976) have argued that the McCollough effect has more of the characteristics of a conditioning phenomenon than of a process of neural fatigue.…”

Persistence of simple and contingent motion aftereffects

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Jones and Holding (1975) showed that orientation-contingent color aftereffects can persist for at least 3 months, but are depleted by repeated testing. We applied the same paradigm to a simple motion aftereffect (MAE) and found that it can persist for up to 1 week and is only slightly diminished by testing.

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