Probe-flash threshold curves were used to show that adaptation to textured fields consists not only of adaptation to the steady local constituents but also of a process that is similar to habituation to prolonged temporal modulation, which in this case could be caused by miniature eye movements across element boundaries. The response curves derived from probe-flash thresholds are compressive on both sides of the adaptation level after adaptation to spatially uniform fields but have an

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... ng form when they are measured after adaptation to textured backgrounds. This change is suggestive of a response equalization process, which modifies the response function of each mechanism to match the cumulative frequency distribution of its inputs.