Spontaneous recovery of motion and face aftereffects

- We test if different adaptation durations engage distinct controlling mechanisms.
- Observers sequentially viewed adapters that produced opposite gain changes.
- After effects due to longer adapter recovered after being eliminated by shorter one.
- This pattern of results was observed in motion and face adaptation.
- Multiple temporally-tuned mechanisms may be a general feature of visual adaptation.

The ability of the visual system to rapidly adjust to changing environmental conditions is one of its key characteristics. Environmental changes can occur over a variety of timescales, however, and it remains unknown how the visual system adapts to these. Does a single mechanism control adaptation across all timescales, or is adaptation subserved by multiple mechanisms, each of which is tuned to its preferred duration? To address this question, we conducted three experiments in which subjects viewed motion (Exp. 1 and 2) or faces (Exp. 3) in a sequence designed to produce opposing aftereffects. A first adapter was presented for a relatively long duration, while a second one was presented only long enough to extinguish the effects of the initial adapter. Continued measurement of aftereffects revealed a spontaneous recovery of adaptation caused by the initial, longer-lasting adapter in all three experiments. This pattern of results suggests that adaptation in the visual system generally reflects a combination of multiple temporally-tuned mechanisms.