Dynamics of contrast adaptation in central and peripheral vision

Abstract

Adaptation aftereffects are generally stronger for peripheral than for foveal viewing. We examined whether there are also differences in the dynamics of visual adaptation in central and peripheral vision. We tracked the time course of contrast adaptation to binocularly presented Gabor patterns in both the central visual field (within 5°) and in the periphery (beyond 10° eccentricity) using a yes/no detection task to monitor contrast thresholds. Consistent with previous studies, sensitivity losses were stronger in the periphery than in the center when adapting to equivalent high contrast (90% contrast) patterns. The time course of the threshold changes was fitted with separate exponential functions to estimate the time constants during the adapt and post-adapt phases. When adapting to equivalent high contrast, adaptation effects built up and decayed more slowly in the periphery compared with central adaptation. Surprisingly, the aftereffect in the periphery did not decay completely to the baseline within the monitored post-adapt period (400 s), and instead asymptoted to a higher level than for central adaptation. Even when contrast was reduced to one-third (30% contrast) of the central contrast, peripheral adaptation remained stronger and decayed more slowly. This slower dynamic was also confirmed at suprathreshold test contrasts by tracking tilt-aftereffects with a 2AFC orientation discrimination task. Our results indicate that the dynamics of contrast adaptation differ between central and peripheral vision, with the periphery adapting not only more strongly but also more slowly, and provide another example of potential qualitative processing differences between central and peripheral vision.

Repulsive Aftereffects of Visual Space

“…Two factors might be responsible for this difference as follows: first, the eccentricity of the probes and, therefore, the activation of more peripheral retinal regions, and second, the distance of the probes to the adapter stimuli. The first hypothesis is likely because visual adaptation is known to generate stronger aftereffects in the periphery, including tilt aftereffects [18,19], motion aftereffects [20,21], shape aftereffects [22,23], face aftereffects [24,25] and contrast aftereffects [26]. Under the second hypothesis, adaptation might be absent (as it was in Experiment 2) because stimuli are presented closer to the adapter, as has already been proposed by [12].…”

“…The following two factors might play a role: the absolute eccentricity of the probe stimuli or the distance between the adapter and probe stimulus. The first factor, i.e., the absolute eccentricity, is likely relevant because many adaptation effects are stronger in the periphery [18][19][20][21][22][23][24][25][26]. The second factor, i.e., the distance between the adapter and probe stimulus, has been suggested by [12].…”

Changes of tuning but not dynamics of contrast adaptation with age

“…The experimental protocol was the same as that of Gao et al (2019). Specifically, each session lasted 900s and consisted of a 200s pre-adapt, 300s adapt and 400s post-adapt period.…”

Number adaptation: A critical look

“…In fact, we are not aware of any robust number adaptation effects that do not depend on the items being presented in the periphery. This point is worth a reflection: There is no obvious reason why number adaptation should be stronger in the periphery, not least because this is (yet again) atypical of visual adaptation in general (e.g., Gao, Webster, & Jiang, 2019;but see, e.g., Zimmermann, 2023).…”